Knee Fractures (Strategies in Fracture Treatments) 303081775X, 9783030817756

Citation preview

Strategies in Fracture Treatments

Marc Hanschen Peter Biberthaler James P. Waddell Editors

Knee Fractures

Strategies in Fracture Treatments Series Editors Peter Biberthaler Klinik u. Poliklinik für Unfallchirurgie TU München Klinikum rechts der Isar München, Bayern, Germany James P. Waddell St. Michael's Hospital Toronto, Canada

This series provides a clearly structured and comprehensive overview of fracture treatments based on the most recent scientific data. Each book in the series is organized anatomically, so the surgeon can quickly access practical aspects, examples, pearls and pitfalls of specific areas. Trauma and orthopaedic surgeons worldwide who are searching for a current knowledge of new implants, therapeutic strategies and advancements will be able to quickly and efficiently apply the information to their daily clinical practice. The books in the series are written by a group of experts from the Association for the Rationale Treatment of Fractures (ARTOF) who aim to provide an independent, unbiased summary of fracture treatments to improve the clinical and long term outcomes for patients. More information about this series at http://www.springer.com/series/13623

Marc Hanschen  •  Peter Biberthaler James P. Waddell Editors

Knee Fractures

Editors Marc Hanschen Department of Trauma Surgery, University Hospital Klinikum rechts der Isar, School of Medicine Technical University of Munich Munich Germany

Peter Biberthaler Department of Trauma Surgery University Hospital Klinikum rechts der Isar, School of Medicine Technical University of Munich Munich Germany

James P. Waddell University of Toronto St. Michael's Hospital Toronto, ON Canada

ISSN 2364-8295     ISSN 2364-8309 (electronic) Strategies in Fracture Treatments ISBN 978-3-030-81775-6    ISBN 978-3-030-81776-3 (eBook) https://doi.org/10.1007/978-3-030-81776-3 © Springer Nature Switzerland AG 2021 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

Contents

1 Anatomy of the Knee ����������������������������������������������������������������������   1 Moritz Crönlein 2 Imaging Following Knee Injury������������������������������������������������������   9 Tina Zahel and Heike Einhellig 3 Epidemiology and Classification of Distal Femur Fractures ������  27 Lukas Negrin 4 Preoperative Planning in Distal Femur Fractures������������������������  41 Adeel Aqil, Vivek Gulati, and James P. Waddell 5 External Fixation of Distal Femur Fractures��������������������������������  49 Arindam Banerjee 6 Nail Osteosynthesis of Distal Femur Fractures ����������������������������  57 Steve Borland, Jeremy Hall, and Aaron Nauth 7 Plate and Screw Osteosynthesis of Distal Femur Fractures��������  67 Jose A. Canseco, Ivan J. Zapolsky, Priya S. Prakash, and Derek J. Donegan 8 Epidemiology and Classification of Proximal Tibia Fractures����  77 Arindam Banerjee 9 Preoperative Planning in Proximal Tibia Fractures��������������������  85 Markus Prause 10 External Fixation of Proximal Tibia Fractures ����������������������������  89 Arthur Schwarz and Marc Hanschen 11 Nail Osteosynthesis of Proximal Tibia Fractures��������������������������  97 Christian von Rüden, Volker Bühren, and Mario Perl 12 Plate and Screw Osteosynthesis of Proximal Tibia Fractures�������������������������������������������������������������������������������� 105 Peter Biberthaler 13 Epidemiology and Classification of Patella Fractures������������������ 113 Alexander von Zelewski, Miriam Kalbitz, and Jochen Pressmar

v

vi

14 Preoperative Planning in Patella Fractures���������������������������������� 119 Michael Müller and Marc Hanschen 15 Wire, Screw and Plate Osteosynthesis of Patella Fractures�������� 123 Michael Müller and Peter Biberthaler 16 Periprosthetic Fractures Around the Knee������������������������������������ 133 Marc Hanschen 17 Floating Knee ���������������������������������������������������������������������������������� 141 Samuel Molyneux 18 Infected Nonunions Around the Knee�������������������������������������������� 159 Jamie Ferguson, Mario Morgenstern, David Stubbs, and Martin McNally 19 Non-infected Nonunions and Malunions Around the Knee �������� 185 Nando Ferreira 20 Posttraumatic Bone Defects Around the Knee������������������������������ 199 Martijn van Griensven 21 Management of Ligament Injuries Following Fractures Around the Knee������������������������������������������������������������������������������ 207 John Keating 22 Management of Chondral Injuries Following Fractures Around the Knee������������������������������������������������������������������������������ 223 Johannes Zellner, Matthias Koch, Johannes Weber, and Peter Angele 23 Challenges in Geriatric Patients with Fractures Around the Knee�������������������������������������������������������������������������������������������� 233 Alexander Martin Keppler, Evi Fleischhacker, Julian Fürmetz, Wolfgang Böcker, and Carl Neuerburg 24 Juvenile Fractures Around the Knee���������������������������������������������� 245 Hamzah Alhamzah, Jimmy Tat, Jong Min Lee, and David Wasserstein 25 Management of Nerve Injury in Knee Trauma���������������������������� 269 Sandro M. Krieg 26 Management of Vascular Injury in Knee Trauma������������������������ 275 Gabor Biro 27 Postoperative rehabilitation following fractures around the knee �������������������������������������������������������������������������������������������� 281 Marcus Schmitt-Sody

Contents

List of Editors

Marc  Hanschen Department of Trauma Surgery, University Hospital Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany James P. Waddell  Division of Orthopaedic Surgery, University of Toronto, Toronto, ON, Canada Peter  Biberthaler Department of Trauma Surgery, University Hospital Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany

vii

List of Authors

Hamzah  Alhamzah Department of Orthopaedic Surgery, College of Medicine, King Saud University, Riyadh, Saudi Arabia Peter Angele  Department of Trauma Surgery, University Medical Center of Regensburg, Regensburg, Germany Sporthopaedicum Regensburg, Regensburg, Germany Adeel  Aqil North Yorkshire Rotation, Northern Lincolnshire and Goole NHS Foundation Trust, London, UK Arindam  Banerjee NH Narayana Multispeciality and Superspeciality Hospitals, Howrah, West Bengal, India Institute of Neurosciences, Kolkata, West Bengal, India Gabor  Biro  Department of Vascular and Endovascular Surgery, Technical University of Munich, School of Medicine, University Hospital Klinikum rechts der Isar, Munich, Germany Wolfgang  Böcker Department of Orthopaedics and Trauma Surgery, Musculoskeletal University Center Munich (MUM), University Hospital, LMU Munich, Munich, Germany Steve Borland  Great North Trauma and Emergency Centre, Royal Victoria Infirmary, Newcastle Upon Tyne, United Kingdom Volker  Bühren, MD Department of Trauma Surgery, BG Unfallklinik Murnau, Murnau, Germany Jose  A.  Canseco Rothman Orthopaedic Institute at Thomas Jefferson University, Philadelphia, PA, USA Moritz Crönlein  Department of Trauma Surgery, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany Derek  J.  Donegan Division of Orthopaedic Trauma, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA, USA Heike  Einhellig  Campus Virchow-Klinikum (CVK), Institut Neuroradiologie, Charité Universitätsmedizin Berlin, Berlin, Germany

für

Jamie Ferguson  Bone Infection Unit, Nuffield Orthopaedic Centre, Oxford University Hospitals, Oxford, UK ix

x

Nando Ferreira  Division of Orthopaedic Surgery, Department of Surgical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa Evi  Fleischhacker Department of Orthopaedics and Trauma Surgery, Musculoskeletal University Center Munich (MUM), University Hospital, LMU Munich, Munich, Germany Julian  Fürmetz Department of Orthopaedics and Trauma Surgery, Musculoskeletal University Center Munich (MUM), University Hospital, LMU Munich, Munich, Germany Martijn van Griensven  cBITE, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, The Netherlands Vivek Gulati  The London Clinic, London, UK Jeremy  Hall  St. Michael’s Hospital, University of Toronto, Toronto, ON, Canada Miriam  Kalbitz Department of Trauma Surgery, University Hospital Erlangen, Erlangen, Germany John  Keating The University of Edinburgh, New Royal Infirmary of Edinburgh, Trauma and Orthopaedic Surgery, Edinburgh, Great Britain, UK Alexander  Martin  Keppler Department of Orthopaedics and Trauma Surgery, Musculoskeletal University Center Munich (MUM), University Hospital, LMU Munich, Munich, Germany Matthias Koch  Department of Trauma Surgery, University Medical Center of Regensburg, Regensburg, Germany Sandro  M.  Krieg  Department of Neurosurgery, Klinikum rechts der Isar, School of Medicine, Technische Universität München, Munich, Germany Jong Min Lee  Division of Orthopaedic Surgery, Toronto, ON, Canada Martin McNally  Bone Infection Unit, Nuffield Orthopaedic Centre, Oxford University Hospitals, Oxford, UK Samuel  Molyneux  The University of Edinburgh, New Royal Infirmary of Edinburgh, Trauma and Orthopedic Surgery, Edinburgh, Great Britain Mario  Morgenstern Klinik für Traumatologie, Universitätsspital Basel, Basel, Switzerland Michael  Müller Department of Trauma Surgery, University Hospital Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany Aaron Nauth  St. Michael’s Hospital, University of Toronto, Toronto, ON, Canada Lukas  Negrin Department of Orthopedics and Trauma-Surgery, Medical University of Vienna, Vienna, Austria

List of Authors

List of Authors

xi

Carl  Neuerburg Department of Orthopaedics and Trauma Surgery, Musculoskeletal University Center Munich (MUM), University Hospital, LMU Munich, Munich, Germany Mario Perl, MD, MHBA  Department of Trauma and Orthopedic Surgery, University Hospital Erlangen, Friedrich-Alexander University ErlangenNürnberg (FAU), Erlangen, Germany Priya S. Prakash  Division of Trauma and Acute Care Surgery, Department of Surgery, University of Chicago, Chicago, IL, USA Markus Prause  Department of Trauma Surgery, Berufsgenossenschaftliche Unfallklinik Frankfurt am Main, Frankfurt, Germany Jochen  Pressmar Department of Trauma Surgery, University Hospital Erlangen, Erlangen, Germany Christian  von Rüden, MD, MSc Department of Trauma Surgery, BG Unfallklinik Murnau, Murnau, Germany Institute for Biomechanics, Paracelsus Medical University, Salzburg, Austria Marcus Schmitt-Sody  Medical Park Chiemsee in Bernau-Felden, Bernau-­ Felden, Germany Arthur Schwarz  Department of Trauma Surgery, Klinikum rechts der Isar, Technical University of Munich, München, Germany David  Stubbs Bone Infection Unit, Nuffield Orthopaedic Centre, Oxford University Hospitals, Oxford, UK Jimmy Tat  Division of Orthopaedic Surgery, Toronto, ON, Canada David  Wasserstein Sunnybrook Health Sciences Centre, Toronto, ON, Canada Division of Orthopaedic Surgery, Toronto, ON, Canada Johannes  Weber Department of Trauma Surgery, University Medical Center of Regensburg, Regensburg, Germany Tina Zahel  Department of Diagnostic and Interventional Radiology, School of Medicine, University Hospital Klinikum rechts der Isar, Technical University of Munich, Munich, Germany Ivan  J.  Zapolsky Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA, USA Alexander  von Zelewski Department for Trauma, Hand, Plastic and Reconstructive Surgery, Ulm University Hospital, Ulm, Germany Johannes  Zellner Department of Trauma Surgery, University Medical Center of Regensburg, Regensburg, Germany Sporthopaedicum Regensburg, Regensburg, Germany

1

Anatomy of the Knee Moritz Crönlein

Abbreviations ACL ALL LCL MCL PCL

Anterior cruciate ligament Anterolateral ligament Lateral collateral ligament Medial collateral ligament Posterior cruciate ligament

1.1

Anatomy of the Distal Femur

The femur condyles represent the broadened distal end of the femur. They can be compared to two side-by-side standing wheels advancing each other in the ventral direction. The condyles are separated by a deep notch, called the intercondylar fossa in the dorsal aspects, and connected by the patellar surface in the ventral aspects [1, 2]. Their biconvex shape in the frontal and sagittal plane corresponds to the concave aspects of the proximal tibia. The curvature radius of the condyles increases from dorsal to ventral, medial from 17 to 38 mm and lateral from 12 to 60 mm [3]. Two small eminences, naming the lateral and the medial epicondyle, serve as femoral attachment of the collateral ligaments. The adductor M. Crönlein (*) Department of Trauma Surgery, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany e-mail: [email protected]

tubercle, placed cranially of the medial epicondyle, marking the medial ridge of the linea aspera, affords the insertion of the adductor magus muscle fibres [2, 4].

1.2

Anatomy of the Proximal Tibia

The proximal tibia is divided into a medial and a lateral plateau by the cartilage free intercondylar eminence [2, 4]. While the medial plateau has a biconcave shape, the lateral plateau is shaped convex in the sagittal view and concave in the frontal view. This results in a good stability between the medial plateau and the medial femur condyle, while the lateral joint in-congruency needs permanent stabilization of the anterior cruciate ligament (ACL) [3]. The tibia plateau has an anatomical retroversion of 3°–9° in the sagittal view, called the tibial slope (see Fig. 1.1) and a deviation of about 3° from lateral to medial in the frontal view [3, 4]. Because of the mentioned slope, the femur condyles tend to slip backwards in case of axial loading. This effect is inhibited by the capsule-ligamentous structures and the menisci. Highest bone density of the proximal tibia was found in the medial compartment. In the extended knee joint, the intercondylar eminence serves as stabilizer against rotational forces and medio-lateral displacement because of its good integration into the intercondylar fossa (see Fig. 1.2) [3, 5].

© Springer Nature Switzerland AG 2021 M. Hanschen et al. (eds.), Knee Fractures, Strategies in Fracture Treatments, https://doi.org/10.1007/978-3-030-81776-3_1

1

M. Crönlein

2 Fig. 1.1 Retroversion of the tibia [3]

4-9

Fig. 1.2  Illustration of an extended knee joint, showing the good integration of the intercondylar eminence into the intercondylar fossa, stabilizing the knee joint against rotation forces and medio-lateral translation [5]

1.3

Anatomy of the Patella

The patella is a flat, triangular-shaped sesamoid bone, integrated into the quadriceps tendon [3, 5]. Its cranial located basis attaches the quadri-

ceps tendon, while its caudal apex serves as origin of the patellar ligament. The convex-shaped front surface is pervaded by small vertical bone canals, which contain fibres of the quadriceps tendon. The tendon is connected to the patella

1  Anatomy of the Knee

surface via Sharpey’s fibres [3, 5]. The back surface of the patella consists of seven different facets, two main facets (medial and lateral) and five smaller facets placed on the patellar rim. The facets are divided by different small ledges. The cranial ¾ of the posterior surface are covered with cartilage and articulate with the femur as the femoropatellar joint, while the caudal ¼ of the surface is cartilage-free [3, 4, 6].

1.4

Cartilage, Ligaments, Meniscus and Capsule of the Knee

1.4.1 Cartilage The knee joint articulates with hyaline cartilage, consisting of chondrocytes, collagen fibres and hyaline ground substance. The cartilage nutrition is assured via diffusion from the synovia which is guaranteed by knee motion as the so called “synovial pump”. The synovial fluid is secreted by the synovial membrane containing hyaluronic acid, which regulates the viscosity. Joint motion decreases the viscosity of the synovia, which enlarges the diffusion rate and vice versa [3].

1.4.2 Ligaments 1.4.2.1 Collateral Ligaments The two collateral ligaments stabilize the knee joint in the frontal view against lateral or medial tilt. The lateral collateral ligament (LCL), as a mostly round-shaped ligament, has its origin at the lateral femoral epicondyle and attaches to the fibula head, leaving a small gap to the joint capsule for the popliteus tendon and the lateral meniscus [3, 5]. In full knee extension, the LCL prevents from varus instability; in knee flexion, the tension of the LCL is reduced, allowing knee rotation [7]. Another ligamentous structure, the anterolateral ligament (ALL), first described in 1879 by the French surgeon Segond, has come into atten-

3

tion in the recent past [7]. With a variable origin at the lateral femoral condyle and an insertion at the anterolateral tibia between Gerdy’s tubercle and the tip of the fibular head, the ALL is meant to provide rotatory knee stability [7–10]. The medial collateral ligament (MCL) is a more broad and flat-shaped ligament, with an origin at the medial femoral epicondyle and an insertion at the medial condyle of the tibia. The posterior fibres are adherent to the knee capsule while the deep surface of the MCL is adherent to the medial meniscus. In full knee extension, the inner parts of the MCL are tensioned which provides from valgus instability (see Fig. 1.3).

1.4.2.2 Cruciate Ligaments The anterior cruciate ligament (ACL) is subdivided into three different bundles, an anteromedial, an intermediate and a posterolateral bundle. It attaches to the anterior intercondylar area and inserts at the medial surface of the lateral femur epicondyle. The ACL limits the knee extension by preventing from anterior subluxation of the tibia in knee extension. It also limits internal and external knee rotation in knee flexion [3, 5, 12]. The posterior cruciate ligament (PCL) consists of two different bundles, the anterolateral and the posteromedial bundle. It attaches to the posterior intercondylar area of the tibia and inserts anterosuperiorly at the lateral surface of the medial femur condyle. The PCL is covered by its own synovial sheath and is surrounded by a well vascularized fat pad due to its extra-articular origin in the embryonic development, which may be an explanation for its good intrinsic healing response [13]. The PCL serves as flexion stabilizer as it limits the posterior tilt of the tibia during knee flexion. In addition, the PCL helps to limit the extension together with the ACL by restricting the anterior tilt of the femur during knee extension [3]. Both of the cruciate ligaments support the collateral ligaments in case of varus or valgus stress. Internal knee rotation increases the tension, while external knee rotation decreases the tension of the cruciate ligaments (see Fig. 1.3).

M. Crönlein

4 Lig. cruciatum anterius Lig.cruciatum posterius

Lig. collaterale laterale

Lig. collaterale mediale posterius Lig. collaterale mediale

Fig. 1.3  Anatomical preparation of an anterior aspect of the knee joint. The illustration shows the relation of the collateral ligaments, the cruciate ligaments and the

menisci to the tibial head from a ventral view in an anatomical preparation [11]

1.4.3 Meniscus

• Minimizing the punctual contact forces by transforming the load energy through deformation • Improving cartilage nutrition

The in-congruency of the knee joint is compensated by the medial and the lateral meniscus, two fibrocartilage and wedge-shaped discs. Anatomically, they can be divided into an anterior and a posterior horn which are attached to the anterior and posterior intercondylar area [5, 14]. An additional fixation between the anterior horns of the medial and lateral meniscus is provided by the transverse ligament. The medial meniscus is of a semilunar shape and covers around 50–60% of the articular surface of the medial tibia plateau, with a mean width of about 10 mm [14]. The lateral meniscus is of a semicircular shape with a mean width of 12 mm [3]. Blood supply is delivered mostly by small vessel entering from the joint capsule to the peripheral 1–2  mm of the meniscus. The more centrally located parts are known for poor vascularity [5, 15, 16]. The main functions of the menisci are: • Enhancement of joint stability • Compensation of joint disparity • Passive limitation of hyperflexion hyperextension

and

1.4.4 Capsule The knee capsule is a cylinder-shaped membrane that embraces the whole knee joint leaving a small gap for the patella. The capsule consists of two different layers, a synovia and a fibrous layer [3]. The fibrous layer is strengthened medially and laterally and attached to the peripheral meniscal base [14]. The synovial layer is highly vascularized, it is constituted by connective tissue, and it is responsible for the production of the synovial fluid [17]. One of the main components of the synovial fluid is hyaluronic acid which has an important role for joint lubrication and cartilage nutrition [18, 19]. The dorsal capsule stabilizes the knee joint against hyperextension as well as internal and external rotation in the extended knee. The medial capsule stabilizes the knee against valgus stress, anterior dislocation and external rotation

1  Anatomy of the Knee

in the flexed knee [20]. The lateral capsule stabilizes against internal rotation in flexion and extension as well as against external rotation in flexion [3].

1.5

 uscles, Nerves and Vessels M of the Knee

1.5.1 Muscles The quadriceps is the most important extensor of the knee joint. Four different portions can be distinguished, the rectus femoris, the vastus lateralis, the vastus medialis and the vastus intermedius. Extension forces are transferred to the quadriceps tendon connected via the patella and the patella tendon to the tibial tuberosity [3]. The slightly weaker flexors of the knee joint can be separated into the hamstring muscle group with the biceps femoris, the semitendinosus and the semimembranosus and the pes anserinus group (gracilis, sartorius and again the semimembranosus). The gastrocnemius and the popliteus only play a minor role in knee flexion. Internal knee rotation is provided by the sartorius, the gracilis, the semimembranosus, the semitendinosus and popliteus muscle, while external rotation is provided by the biceps femoris and the tensor fasciae latae [3].

1.5.2 Vessels Blood supply of the knee joint is delivered by the popliteal artery. The popliteal artery passes the popliteal fossa and delivers five different branches, communicating with each other through numerous anastomoses as the so-called rete articulare genus [5]: • • • • •

A. superior lateralis genus A. superior medialis genus A. medialis genus A. inferior lateralis genus A. inferior medialis genus

5

1.5.3 Nerves Innervation of the knee joint follows Hilton’s law through the nerves that additionally innervate the muscles that supply knee motion [5]. A medially placed nervous network for the innervation of the medial knee joint is supplied by branches of the tibial nerve, while a laterally placed nervous network for the innervation of the lateral knee is provided by the peroneal nerve. A cranial innervation is provided by few small branches submitted by the femoral nerve. Even small branches from the obturator nerve enter the knee joint from the craniomedial region with a very complex innervation pattern [5].

1.6

Functional Anatomy of the Knee

Knee motion is a complex mechanism that includes rolling, gliding and a terminal rotation. This complex motion was first described by Weber et al. in 1836 [11]. To understand the kinematics of the knee during extension and flexion, the femoral and tibial contact points were marked in a sagittal plane during knee motion. Weber et  al. found out that on the one hand, the tibial contact points shifted backwards during knee flexion and that on the other hand, the distance between the femoral contact points during flexion was twice as much as the distance of the tibial contact points [3]. With this experimental study, Weber et al. stated that the femoral condyles perform a roll and glide mechanism on the tibia plateau, which prevents from femoral posterior luxation and at the same time enlarges the knee flexion [3]. Further studies showed that during the first 20°–30° of knee flexion, there is only rolling motion, while in further flexion the articular surfaces glide on each other (see Fig. 1.4) [3, 11, 21]. Another motion has been described by Mayer et  al. in 1853 [11], naming the terminal rotation during the last 20° of knee extension [22]. The terminal rotation describes a 10° external rotation of the knee joint, enabled by the ACL

6

M. Crönlein

Fig. 1.4  Kinematics of the knee [3]. Illustration of the role and glide mechanism of the knee joint during flexion. The connection points of the medial femoral condyle and the tibia are marked. While the first 20° of knee flexion is predominated by rolling mechanisms, gliding mechanisms predominate during further knee flexion

and the iliotibial tract. At the end of this additional compulsory knee motion, the collateral ligaments are tensioned, and the knee joint is physiologically subluxated, with the femur condyles being wedged into the tibial articular surface, providing additional stabilization of the knee joint in full extension. Making another knee flexion possible, terminal rotation has to be dissolved by tension of the internal rotators [22].

References 1. Strobel M, Stedtfeld H-W, Eichhorn HJ. Anatomie, Propriozeption und Biomechanik. In: Strobel M, Stedtfeld H-W, Eichhorn HJ, editors. Diagnostik des Kniegelenks. 2nd ed. Berlin: Springer; 1990. p. 2–52. 2. Wagner M, Schabus R.  Knöcherne Strukturen. In: Wagner M, Schabus R, editors. Funktionelle Anatomie des Kniegelenks. Berlin: Springer; 1982. p. 3–10. 3. Jerosch J.  Endoprothesenrelevante Biomechanik und Pathophysiologie des Kniegelenks. In: Jerosch J, Heisel J, Tibesku CO, editors. Knieendoprothetik. 2nd ed. Berlin: Springer; 2015. p. 5–27. 4. Jagodzinski M, Müller W, Friederich N.  Anatomie. In: Jagodzinski M, Friederich N, Müller W, editors. Das Knie  – Form, Funktion und ligamentäre Wiederherstellungschirurgie. 2nd ed. Berlin: Springer; 2015. p. 1–14. 5. Prescher A. Anatomie des Kniegelenks. In: Wirtz DC, editor. AE-Manual der Endoprothetik – Knie. Berlin: Springer; 2011. p. 1–17. 6. de Oliveira SD, Briani RV, Pazzinatto MF, Goncalves AV, Ferrari D, Aragao FA, et al. Q-angle static or dynamic measurements, which is the best choice for patellofemoral pain? Clin Biomech. 2015;30:1083–7.

7. Claes S, Vereecke E, Maes M, Victor J, Verdonk P, Bellemans J.  Anatomy of the anterolateral ligament of the knee. J Anat. 2013;223:321–8. 8. Roessler PP, Schüttler KF, Stein T, Gravius S, Heyse TJ, Wirtz DC, et  al. Anatomic dissection of the anterolateral ligament (ALL) in paired fresh-frozen cadaveric knee joints. Arch Orthop Trauma Surg. 2017;137:249–55. 9. Helito CP, Bonadio MB, Rozas JS, Wey JMP, Pereira CAM, Cardoso TP, et  al. Biomechanical study of strength and stiffness of the knee anterolateral ligament. BMC Musculoskeletal Disorders. 2016;17(193):193–9. 10. Petersen W, Zantop T.  Anatomy of the lateral and medial stabilizers of the knee. Arthroskopie. 2017;30:4–13. 11. Jagodzinski M, Mueller W, Friederich N. Kinematik und angewandte Physiologie und Pathophysiologie der Ligamente. In: Jagodzinski M, Friederich N, Mueller W, editors. Das Knie – Form, Funktion und ligamentäre Wiederherstellungschirurgie. 2nd ed. Berlin: Springer; 2015. p. 15–59. 12. Dargel J, Gotter M, Mader K, Pennig D, Koebke J, Schmidt-Wiethoff R.  Biomechanics of the anterior cruciate ligament and implications for surgical reconstruction. Strategies Trauma Limb Reconstr. 2007;2(1):1–12. 13. Schüttler KF, Ziring E, Ruchholtz S, Efe T. Posterior cruciate ligament injuries. Unfallchirurg. 2017;120:55–68. 14. Smigielski R, Becker R, Zdanowicz U, Ciszek B.  Medial meniscus anatomy—from basic science to treatment. Knee Surg Sports Traumatol Arthrosc. 2015;23:8–14. 15. Arnoczky SP, Warren RF.  Microvasculature of the human meniscus. Am J Sports Med. 1982;10(2):90–5. 16. Henning CE, Lynch MA, Clark JR.  Vascularity for healing of meniscus repairs. Arthroscopy. 2010;26(10):1368–9. 17. Oliveira I, Goncalves C, Reis RL, Oliveira JM.  Synovial knee joint. In: Oliveira JM, Reis RL, editors. Regenerative strategies for the treatment

1  Anatomy of the Knee of knee joint disabilities. Berlin: Springer; 2017. p. 21–8. 18. Iwanaga T, Shikichi M, Kitamura H, Yanase H, Nozawa-Inoue K.  Morphology and functional roles of synoviocytes in the joint. Arch Histol Cytol. 2000;63(1):17–31. 19. Tandon PN, Agarwal R.  A study on nutritional transport in a synovial joint. Comput Math Appl. 1989;17(7):1131–41. 20. De Maeseneer M, Van Roy F, Lenchik L, Barbaix E, De Ridder F, Osteaux M. Three layers of the medial

7 capsular and supporting structures of the knee- MR imaging-anatomic correlation. Radiographics. 2000;20:83–9. 21. Duda GN, Heller MO, Pfitzner T, Taylor WR, König C, Bergmann G.  Biomechanik des Kniegelenks. In: Wirtz DC, editor. AE-Manual der Endoprothetik  – Knie. Berlin: Springer; 2011. p. 19–29. 22. Fuss FK.  Principles and mechanisms of automatic rotation during terminal extension in the human knee joint. J Anat. 1992;180:297–304.

2

Imaging Following Knee Injury Tina Zahel and Heike Einhellig

2.1

Plain Imaging

2.1.1 Introduction Plain imaging of the knee in an acute knee trauma is one of the most frequently performed radiological examinations in emergency departments [1, 2]. In spite of newer technologies, plain imaging sustains its position. It is readily available, faster, and cheaper compared to computed tomography. In addition, it enables an easy overview for therapy planning and helps to avoid delayed diagnoses, which may result in a poorer clinical outcome. Routinely performed two views [anterior posterior (ap) view, lateral view] are the minimum for initial evaluation of acute injuries of the knee. In some cases, even for specialists, it is quite difficult or even impossible to detect subtle fractures on radiographs. Undislocated fractures can

be missed, e.g. depression fracture of the tibia, stress, or insufficiency fractures. Additional views such as skyline patellar and tunnel view, oblique views, or ap views with varus and valgus stress can be helpful to increase sensitivity of fracture diagnostics [3–6]. Fractures can be missed due to insufficient positioning of the patient (dislocation, pain). It was proven that 15% of patients, especially those with multiple fractures, show an insufficient positioning, which may prohibit an accurate fracture diagnosis or fracture exclusion [7]. It has been suggested that four views (e.g. obliques) instead of two standard views (ap and lateral) show a higher sensitivity in fracture detection [5]. In daily emergency routine, two radiographs perpendicular to each other are the initial diagnostic procedure. Special views can be performed to improve evaluation of superimposed structures such as intercondylar area or patella (Fig. 2.1).

T. Zahel Department of Diagnostic and Interventional Radiology, School of Medicine, University Hospital Klinikum rechts der Isar, Technical University of Munich, Munich, Germany e-mail: [email protected] H. Einhellig (*) Campus Virchow-Klinikum (CVK), Institut für Neuroradiologie, Charité Universitätsmedizin Berlin, Berlin, Germany e-mail: [email protected] © Springer Nature Switzerland AG 2021 M. Hanschen et al. (eds.), Knee Fractures, Strategies in Fracture Treatments, https://doi.org/10.1007/978-3-030-81776-3_2

9

T. Zahel and H. Einhellig

10

a

b

c

Fig. 2.1  Vertical patella fracture. Almost invisible in standard views. Best seen in axial view. (a) ap view (b) lateral view (c) axial view

The ossification of the patella starts between 3 and 5  years and normally ends in adolescence. Incomplete ossification with remaining ossification centres can mimic patella. The epiphyses of the distal femur and the proximal tibia and proximal fibula are present until 17–19 years [8].

2.1.2 Technique For all views the patient has to undress his/her knee. Woman need to negate pregnancy. Gonadal protection or lead gown must be attached. The average effective dose of the knee is approximately 0.01 mSv for radiography [9].

2.1.2.1 Standard Views Knee Anteroposterior (AP) View The main indication for knee radiography is fracture diagnosis in emergency departments. Most of the times, fractures of the femoral condyles or tibia plateau can easily be seen on ap views, especially in cases with dislocation. But a closer look is necessary to evaluate other osseous injuries such as Segond fracture, intercondylar tubercles fracture, or luxation (displacement of the tibia with respect to the femur). Also (lipo-)hemarthrosis (joint effusion arranged in layers in the recessus patellaris) is a good indirect sign in serious knee injuries in case of joint involvement of the fracture. Beyond that, knee radiography is also performed in non-acute situations, e.g. for

tumours, infections, degeneration, osteochondritis dissecans, or Osgood-Schlatter. Patella fractures or non-dislocated tibia plateau fractures are often missed in standard ap views. For an ap view, supine position of the patient with stretched legs (sometimes minimal flexion in the joint) is necessary. The leg is normally rotated inwards by placing femoral epicondyles parallel with a centred patella. The central ray must be orthogonal on the joint space (about 1 cm below the lower patella apex) with passing x-rays from anterior to posterior. In some cases, the tube is angled to the patella apex in an angle of 5°–7° cephalad (Fig. 2.2). Quality criteria for ap views of the knee are an open femorotibial joint space, symmetrical located femoral condyles with a centred patella, a line appearance of the lateral tibia plateau, and a slightly oval appearance of the medial tibia plateau. The fibula head is partially superimposed by the tibia. The patella is completely superimposed. Potential mistakes are made if (1) the knee is not in the centre of the radiograph; (2) the knee is not stretched enough (the lower patella pole covers the eminentia intercondylaris and the lateral tibial plateau gets an oval shape); and (3) the patella is not medial enough [fibula head projects itself on the tibial head and the distal part of the patella protrudes the distal femur. Or the patella protrudes the medial side of the femoral edge and the fibula head is almost completely visible if the central ray is displaced (results in an oval shape of the medial and lateral tibia plateau)].

2  Imaging Following Knee Injury

11

1

Technical factors 2 3

3` 4 5

different technical factors for children

7

a

RG: none (big object: r 8) SID: 105 (115 cm) exposure automatic: free exposure or middle measuring chamber exposure: 60-75 kV; 2,5-3,2 mAs

6

b

Radiation grid(RG) source-to-image-recepter distance (SID)

1 Femur 2 Patella 3 Medial femoral condyle 3’ Lateral femoral condyle 4 Eminentia intercondylaris with Tuberculum intercondylare mediale and laterale 5 Tibia head 6 Tibial shaft 7 Fibula head

Fig. 2.2 (a) Positioning for ap view (b) anatomy of ap view

Shortcomings of an ap view of the knee especially apply to the patella and the tibial head. In an ap view of the knee, it is often hard to distinguish a true patella fracture from a patella bipartite (upper outer quadrant affection) or other osseous variants. For this reason, additional views may be necessary. Some fractures, e.g. depression fractures of the tibia, can also be subtle in an ap view. For preventing an overlook of a tibia fracture, it can be helpful to follow the osseous tibial joint contour for interruptions or irregularity. Also the tibiofemoral alignment should be correct (shift less than 5  mm). If hemarthrosis is visible, further investigation is indispensable, even if no osseous injury can be seen on radiographs. Valgus and varus stress views are options for evaluation of collateral ligaments. Further imaging techniques such as ap weight-­ bearing (Rosenberg) or ap weight bearing radiographs are meant for evaluation of joint space narrowing and are not meant for fracture evaluation.

Knee Lateral The lateral view is part of standard knee diagnostics. It enables an uncovered look on the patella in a lateral profile. Also the distal part of the femur, the proximal ends of the fibula and tibia, and the adjacent soft tissues (quadriceps and patellar tendon and suprapatellar pouch) can be assessed. This view is the optimal choice to look for lipohemarthrosis. Moreover, suspicions of luxation, osteoarthritis, or Osgood-Schlatter are typical indications. The patient lies in an exact lateral position on his/her affected side. The affected knee is slightly flexed (30°–45° flexion; relaxation of the muscles with view on the maximum volume of the joint space) and brought forwards to bring the knee into a lateral position on the image receiver (IR). The unaffected leg is almost stretched and far in front of the affected knee. Immobile patients can put the healthy leg behind the x-rayed knee. The foot of the affected knee is positioned with a wedge-shaped bolster. The epicondyles and the patella must be vertical to the plane of the under-

T. Zahel and H. Einhellig

12

lay and congruent with each other. Sometimes fixation of the healthy side with bolsters is necessary to avoid overrotation of the body. The central ray is focused, perpendicular mediolateral to the knee joint space, and 2 cm below the apex of the patella. The x-ray tube can be slightly angulated for a perpendicular central ray to the joint space (5° angle cephalad) (Fig. 2.3). Another highly preferred option for lateral radiographics for severely injured or immobile patients is the horizontal beam view (cross lateral view). Patients lie on their back. The affected and slightly flexed (ca. 30°) knee is supported with bolsters. The patella is oriented frontwards. The image receiver is positioned medial with a lateromedial central beam. Quality criteria are congruent femoral condyles to each other, an open retropatellar space, and a plane-parallel appearance of the tibial ­bearing area. The patella shows a lateral profile. The fibular head is hidden in the posterior part of the tibia. Low quality is performed with nonmatching condyles. Either the leg is overturned too much

a

or too little. If so, one can see the full fibula head with an overlain patella or you can find an overlain fibula head and an overlain patella. If the femur condyles show a double contour, the lower leg is not in the same height as the thigh. Lateral views are often better for evaluation of anterior or posterior depression of the tibia plateau. But even in the lateral view, it is often hard or even impossible to evaluate the posterior portion of the tibial head [6, 10]. Here the tibial plateau view can be helpful (15° view with tangential central beam to the tibia plateau). Lateral views can also be helpful to exclude undisplaced fractures of the eminentia intercondylaris [11]. Evaluation of discontinuity of the cortical margin of the distal femur (especially supracondylar) is possible. Tibia plateau fractures can be seen as discontinuity or sclerosis due to impaction. The patella for horizontal fractures can be evaluated (but vertical fractures are often invisible in the lateral view). Dependent on the clinical findings and the result of the standard views, further views are

b 1 3 4 Technical factors 2 See ap view

5 6 7

8 1 Femur 2 Condylus femoris 3 Patella 4 Femoropatellar joint 5 Eminentia intercondylaris mediale and laterale 6 Tibia head 7 Tuberositas tibiae 8 Fibula head

Fig. 2.3 (a) Positioning for lateral view, (b) anatomy of lateral view

2  Imaging Following Knee Injury

required. Joint effusion can be an indirect sign for meniscal tears and appears as soft tissue density extending behind the quadriceps and prepatellar tendon. The patella can be displaced anteriorly or inferiorly due to large effusions. For evaluation of ligamentary injuries of the ACL or PCL, stress radiography is possible (Fig. 2.4).

2.1.2.2 Additionals Patella Axial View Main indications are vertical fractures, luxations, and degeneration with focus on the patellofemoral joint.

13

The axial view is the main view in suspicion of patella fracture [7]. Never initiate a patella axial view in cases of transverse or fixed patella fractures. Several techniques to perform an axial image of the patella exist. The sunrise patella view with a patient in a prone position is the most commonly used projection. Maximum flexion of the preferred knee is necessary for this projection. The ideal positioning shows contact between the thigh and lower leg and a vertical orientation of the patella to the image receiver. The leg can be fixed with a band (Fig. 2.5). The central ray is angled on the femoropatellar joint and the middle of the image receiver. If

a

b

1 2 3 4

Evidence of ACL ruptur in stress test 1 Pushing focus 2 Patella 3 Condylus femoris 4 Distance of mismatch

Fig. 2.4 (a) Positioning and pressure points for ACL and PCL with Telos device. (b) Evidence of ACL rupture in stress test

a

b

1

2 3 4 1 Patella 2 Lateral femoral condyle 3 Medial femoral condyle 4 Femoropatellar joint

Fig. 2.5 (a) Positioning for axial view in mobile patients, (b) anatomy of axial view

14

the joint is not perpendicular, an angulation of the central beam of 15–20% is necessary. Well-performed axial views provide insight into an open femoropatellar joint. It can be difficult to reproduce the axial view in prone position due to knee mobility dependent on pain. In cases of immobile patients, the patella view is also possible for sitting or lying patients. But radiographs in a sitting position are associated with a higher radiation exposure. The patient sits or lies with a flexed (about 45°) knee. Stabilization of the knee with wedge-­ shaped bolster is necessary. The patient holds the x-ray plate with his hands and positions the image receiver above the knee perpendicular to the longitudinal axis of the patella (image receptor distance 115 cm). The central ray is focused axial on the femoropatellar joint/perpendicular to the lower patella pole perpendicular to the image receiver. The beam path enters horizontal from caudal (if necessary 5°–10°).

Mistakes are made in case of quadriceps tension (shifted patella) or non-visible femoropatellar joint (beam path incorrect). For further evaluation of the femoropatellar joint or patella luxation, the so-called en-défilé series (30°, 60°, 90° knee flexion) are possible with increasing knee flexion angle and increasing x-ray tube angulation for tangential horizontal central beam on the femoropatellar joint. Tunnel View Loose bodies, degeneration, and fractures with joint involvement in the area of the femur con-

T. Zahel and H. Einhellig

dyles (posteroinferior surface), intercondylar fossa, and intercondylar eminence are typical indications for tunnel view. Supine position of the patient with an angled knee (45°; fixation of the knee with sandbags). Leg with a slight internal rotation. The patella is centred between the femur condyles. The central ray is zoomed in on the joint space (beneath lower patella pole) in vertical direction to the axis of the lower limb. The image receiver is underneath the knee lying on the examination table. Alternative the patient is in prone position with a flexed knee (45°) and a patella resting on the IR (Fig. 2.6). Adequate tunnel views offer an open fossa intercondylaris with a line-like lateral tibia plateau and non-covered femoral condyles. Failed tunnel views show a covered tunnel due to external leg rotation or non-vertical central ray. Oblique (Internal or External Rotation) Oblique fractures of the femur condyles, fibula head fractures, epiphysial injuries, or small avulsion fractures or non-dislocated fractures especially of the tibia often need additional imaging, because they can be easily diagnosed in an oblique view radiograph. However, limitation is found by mobilization of injured patients. Further tumours or inflammatory joint changes or fracture of the fibula head can be assessed. Supine position with a stretched knee. Foot and leg show an internal or external rotation (foot/lower limb rotation of 45° inwards or outwards); fixation with wedge-shaped bolster). The central beam is orthogonal on the knee joint space from ventrodorsal and latermedial or ventrodorsal and mediolateral (Fig. 2.7). Criteria for a well-performed oblique radiograph are an open knee joint space and a partially non-covered patella. The fibula head is completely free by 45° internal rotation (fibula head view). Most of the other known knee imaging projections are not used for emergency diagnostics, but they may be used for other clinical indications, e.g. osteoarthritis.

2  Imaging Following Knee Injury

a

15

b Technical factors

50°

45°

RG: no Filter: no SID: 105 cm Exposure: 60-75 kV; 3,2 mAs 1 IR: 18x24 cm, landscape Collimation: centre

1` 2 3

c

4

different technical factors for children

90° 5 45° 1 Medial femoral condyle 1‘ Lateral femoral condyle 2 Fossa intercondylaris (tunnel) 3 Eminentia intercondylaris 4 Tibia head 5 Fibula head

Fig. 2.6 (a) Possibilities of positioning for tunnel view, (b) anatomy of tunnel view

a

b 5 5

1

1`

3

1` 3

2

2` 4

4

45° internal rotation 1 Lateral femoral condyle 1‘ Medial femoral condyle 2 Lateral Tibia plateau 2‘ Medial Tibia plateau 3 Eminentina intercondylaris 4 Fibula head 5 Patella

Fig. 2.7  Anatomy of (a) internal or (b) external rotation

45° external rotation

16

2.1.3 Examples and Catches to Avoid (Courtesy of Klinikum recht der Isar, Munich, Germany, Institute of Radiology) Lateral Tibia Plateau Fracture

Multifragmentary fracture of the tibia head with impression of the lateral tibia plateau

Patella Fracture

Almost invisible fracture line of the patella fracture in ap view

T. Zahel and H. Einhellig

2  Imaging Following Knee Injury

17

(Lipo-)hemarthrosis

Fat-blood fluid level (*) (lipohemarthrosis) in a patient with multifragmentary fracture of the tibia head. Best seen in lateral view

Intercondylar Eminence Fracture

Intercondylar eminence fracture with involvement of the medial tibia plateau. Additional impression fracture of the dorsal part of the lateral tibia plateau

18

T. Zahel and H. Einhellig

Segond Fracture

Avulsion fracture of the lateral tibia head. Further MRI evaluation with special focus on ACL is essential

Osgood-Schlatter Disease

Osgood-Schlatter with bony rest

2  Imaging Following Knee Injury

19

Pellegrini-Stieda Disease

*

Posttraumatic ossification (*) of the medial collateral ligament adjacent to femoral margin in a patient with reconstructed ACL

Fabella

Common sesamoid bone in the lateral head of the m. gastrocnemius in a knee with osteoarthritis

T. Zahel and H. Einhellig

20

Patella Bipartite a

b

(a) Patella bipartita with non-ossification superolateral (loco typico) and non-sharp fragments, (b) Horizontal patella fracture with sharp fragments

2.2

Special Imaging

2.2.1 Introduction The knee is an anatomically complex joint. Various ligamentous, tendinous, and meniscal structures attaching to the bone are prone to injury. In trauma patient workup, it is crucial to detect, visualize, and classify even small fractures. Availability and quality of modern imaging techniques aside from plain radiography have rapidly developed in the last decade. Nowadays, it is unthinkable in many clinical issues to abstain from cross-sectional imaging techniques like computed tomography (CT) or magnetic resonance imaging (MRI).

2.2.2 Imaging Modalities 2.2.2.1 Computed Tomography (CT) Two-plane radiography still is the gold standard in fracture diagnosis. Most special projections in plain radiography, however, have become obsolete. They have been replaced by CT. If clinical findings are suggestive of fracture, even though

standard projections in plain radiography are negative, additional CT imaging is advisable [12]. The first prototype CT scanner, developed by Godfrey Newbold Hounsfield, was used 1971 in London, England. Cross-sectional CT images are based on the radiodensity of different human tissues. Density measurements are documented in Hounsfield units. It was in the early 1970s that CT was first used in hospitals. Since then, technology has rapidly developed. In the early 1990s, the introduction of spiral CT scanners allowed for a continuous movement of the patient through the CT scanner. Instead of acquiring single slices, volumetric data could now be collected. Thus, multiplanar reconstructions were possible. Soon the introduction of multidetector scanners (MDCT) followed. Acquisition of multiple slices at the same time was now feasible in a short time. Thinner slides could be scanned in a much shorter time. In 2005, the first dual-source CT scanner was introduced. Dual-energy CT scanners have two x-ray sources with different energy levels rotating at the same time. They allow for a more precise tissue characterization. Postprocessing methods include multiplanar reformation (MPR), maximum intensity projec-

2  Imaging Following Knee Injury

tion (MIP), and volume rendering techniques (VPR). MPR and MIP are two-dimensional reconstructed images in any optional plane, the standard being axial, coronal, and sagittal. MIP images reconstruct highest density objects, e.g. contrast agent in vessels. VPR are three-­ dimensional images. The latter may be used for a better visual understanding in clinical demonstrations or for the patient [13]. In the acute polytrauma setting, computed tomography has become indispensible. It has been shown that whole-body CT increases the probability of survival in these patients. Whole-­ body CT scans, however, are associated with high radiation exposure (10–20 mSv). Particularly in the non-acute setting, it is reasonable to keep radiation dose low [14]. To reduce radiation exposure, it is important to apply radiation according to the ALARA (= as low as reasonably achievable) principle. This principle most importantly implies that examinations should be targeted to selective organs or anatomic regions and that the potentially harmful effects of radiation have to be weighed against good quality images. Effective radiation exposure for plain radiography series of the knee is estimated with 0.02 mSv, while it is approximately tenfold higher for a computed tomography.

21

Specifically designed imaging protocols and modern data processing techniques, e.g. iterative reconstruction algorithms, allow for considerable dose reduction as well as image quality improvement [15]. In general, CT aids in the clinical decision-­ making process for conservative or surgical measures of knee fractures. It is important to depict the full extent of the fracture and the fracture pattern. This is particularly true for fractures that involve the joint (Fig. 2.8). Classification systems like the Schatzker classification have been useful to assess initial fracture patterns, plan operative management, and predict prognosis [16]. Furthermore, CT scans may visualize certain types of fractures of the knee joint better compared to plain imaging. CT can reveal radiographically occult fractures—e.g. of the posteromedial corner [17]. Simple patella fractures are usually diagnosed in plain radiography; however, in certain cases, e.g. patella bipartita, complex fractures, or suspicion of osteochondral lesions, additional CT scan may be useful [18]. Tibial plateau fractures generally involve cortical interruption and depression or dislocation of the articular surfaces. Dislocated fractures are associated with a higher risk of ligamentous injuries, which may need further treatment. Compared to

Fig. 2.8  Fracture of the lateral tibia plateau (left: coronar image; right: sagittal image). CT depicts cortical fracture lines with minor displacement and lipohemarthrosis

22

plain radiography, in complex cases, CT scans render a more accurate visualization of the articular surface. They can also give a diagnostic clue to ligamentous or other soft tissue injuries. It has been shown that initial treatment strategies (based on plain radiography) were modified after exact fracture depiction on CT scans [16]. Knee fracture surgeries, particularly of the tibial plateau, can be very challenging. To result in optimal function of this weight-bearing joint and to avoid early postoperative osteoarthritis, it is necessary to adapt fractures correctly. Congruency of the articular surface needs to be achieved and ligamentous stability needs to be restored. Thus, it is vital to know fracture depression and displacement. CT gives the surgeon important information (fracture depiction, fracture classification, etc.), which facilitates preoperative planning, including operative access or material choice [19]. In addition, volume rendering techniques with 3D pictures can better visualize fracture extent. These pictures are also used in clinical routine to inform the patient about the planned procedure. CT scans are used on a routine basis to check for the postoperative status, including extraneous material positioning, fracture adaptation, or healing process. Furthermore, in the follow-up, CT aids in the analysis of femoral torsion, especially in patients with chronic instability of the patella or knee osteoarthritis [20]. If needed, application of intravenous iodinated contrast media can better depict potential vessel injury or vessel status. This is particularly true for majorly displaced fractures, lack of pulse in the distal joint, and in suspicion of bleeding (Fig. 2.9). For vessel depiction in knee injuries, CT angiography (CTA) has replaced conventional angiography for the most part [16].

T. Zahel and H. Einhellig

alignment changes are captured as a signal by a receiver. Additional magnetic fields (gradients) are applied to the patient to allow for selective slice selection in the human body. The data of collected signals can then be used for further image processing, much like image processing in CT scans. In contrast to other imaging techniques like CT, in MRI more than one tissue-specific parameter determines the contrast of the image. These are proton density, T1, and T2 relaxation times of tissue [21]. A standard protocol for evaluating knee injuries should include water-sensitive pulse sequences in three different planes (axial, coronal, sagittal). Furthermore, an additional T1-weighted image should be included in the protocol. Evaluation of cartilage requires high spatial resolution; thus, 3D gradient echo sequences can additionally be performed [22]. In the postoperative patient, it may be useful to adapt MR protocols to avoid susceptibility artefacts by metallic implants. Intermediate-weighted TSE sequences with fat suppression are suitable. In suspicion of infection, additional intravenous contrast agents may be used with T1-weighted images. For further diagnostic workup, MR arthrography may be useful. For this examination, a gadolinium-based contrast agent is directly administered to the knee joint [23]. In the past, clinicians have mostly relied on physical examination and arthroscopy for ligamentous injuries. Nowadays, MRI may be a good addition or alternative in many cases. The advantage of MRI compared to other imaging techniques is its good soft tissue contrast. While CT delivers mostly indirect signs for soft tissue injuries, MRI can directly depict ligamentous and meniscal structures and surrounding soft tissue including muscle (Fig. 2.10). Furthermore, it can 2.2.2.2 Magnetic Resonance Imaging depict cartilage and osteochondral lesions. The (MRI) disadvantages of MRI are prolonged examination The basis for magnetic resonance imaging (MRI) times, costs, and availability. is the magnetic field, to which the patient is subFor a simple bony depiction, CT scans are sufjected when placed in the scanner. A radio-­ ficient and more precise, particularly in shatter frequency pulse is applied by a transmitter. This fractures. CT can better show the number and causes changes in magnetization alignment of dislocation of fragments. These types of fractures molecules in the human body. These molecule are usually prone to open repair, and conse-

2  Imaging Following Knee Injury

23

Fig. 2.9  III° complex, open fracture of the knee joint with extensive soft tissue injuries. CT after application of iodinized contrast media depicts not only the fracture displacement and soft-tissue derangements, but also vessel

involvement. A reconstructed 3-D image (upper right) shows the complexity of the fracture with multiple fragments

quently soft tissue will be looked at intraoperatively [24]. In the pain-driven trauma patient, clinical examination can be challenging. Prokop et  al. describe 63% soft tissue injuries in patients with tibial plateau fractures. To result in the best outcome, it is important to detect tissue injuries early to plan the best therapeutic concept [24].

MRI has become an alternative to diagnostic knee arthroscopy in the primary assessment of the knee in many trauma patients. It has shown a high sensitivity to detect internal derangements. Preoperative planning based on MRI images may facilitate and thus shorten surgical procedures [16]. Furthermore, MRI is excellent for the evaluation of knee cartilage. Friemert et al. could show that MRI

24

T. Zahel and H. Einhellig

Fig. 2.10  Fracture of the lateral tibia plateau with typical bone marrow edema. Fracture lines extent to the cortex. Tibial cartilage shows a small fissure. MRI also depicts

rupture of the lateral collateral ligament (left: PD fatsat weighted coronar image) and lipohemarthrosis (right: T1 weighted sagittal image)

Fig. 2.11  Bony avulsion fracture of the anterior cruciate ligament. Typical bone marrow edema after contusion of the lateral femoral condyle, lateral tibia plateau and fibula

head in a pivot-shift injury. PD fatsat weighted images depict the bone marrow edema and accompanying soft tissue injuries

imaging has a very high specificity (97–99%) for cartilage lesions in tibial plateau fractures [25]. MRI is very sensitive in the detection of bone marrow oedema resulting from injury (Fig. 2.11). The location of the marrow oedema in the femur or tibia gives a clue to the injury mechanism. In pivot shift injuries, marrow oedema is usually found in the posterior aspect of the lateral tibial plateau and the lateral femur condyle. In this type

of trauma, accompanying soft tissue injuries including cruciate ligaments, menisci, and posterolateral corner structures are common. Marrow oedema located medially in the patella and/or the lateral femur condyle, or large effusion, and soft tissue oedema at the knee joint are suggestive of recent dislocation [12]. Furthermore, MRI may be useful in the detection of fractures that are occult even in CT scans.

2  Imaging Following Knee Injury

Stress and insufficiency fractures can easily be detected in MRI because of bone marrow oedema. MRI also depicts underlying degenerative changes like osteonecrosis, cysts, or even malignant lesions, which need to be differentiated from acute traumatic lesions [26]. MRI may be used in the follow-up of patients after surgery, particularly to visualize soft tissue structures or to detect posttraumatic changes, e.g. chronic osteomyelitis. Transplant failure of cruciate ligaments, reruptures, graft impingement, arthrofibrosis, ganglionic degeneration, and infection are typical postoperative complications that can be detected on MRI scans. Although MRI seems to be indispensable in the pre- and postoperative workup of knee injuries, standard guidelines for the use of MRI in these injuries are still lacking.

2.2.2.3 Ultrasound The most readily accessible, cost-efficient imaging method remains ultrasound (US). US neither requires ionizing radiation like plain radiography or CT nor long examination times as in MRI. Ultrasound aids in the detection of muscle tears. These are usually detected through hypoechoic changes (fresh blood) without the typical ripple of muscle. In knee trauma, ultrasound is used to look at the quadriceps tendon, the ligamentum patellae, and collateral ligaments. Tears in tendons usually also show hypoechoic changes. Cruciate ligaments and menisci are not a domain of ultrasound [26]. When using ultrasound to look for fractures, it is advisable to search for the normal continuous hyperechoic interface between bone and soft tissue. If this layer is disrupted, a fracture is likely. The most important indirect sign for fracture is the detection of lipohemarthrosis. It is usually seen on ultrasound as either a heterogeneous collection with two (hyperechoic fat and anechoic blood) or three layers (fat, anechoic serum, blood). Only infrapatellar fat pad rupture is a differential diagnosis to lipohemarthrosis. Using direct and indirect signs, sensitivity for fracture detection in ultrasound has been described to be 94%. In addition, colour Doppler ultrasound (colour Doppler) can be used to look for vascular trauma or reduced blood flow.

25

Nevertheless, ultrasound is time-consuming, observer dependent, and the extent and direction of the fracture line or displaced fractures are not sufficiently depictable [27].

2.2.2.4 Arthrography Arthrography of the knee joint is an invasive procedure, which can be combined with cross-­ sectional images, both CT and MRI.  Contrast media needs to be injected directly into the joint, usually using fluoroscopic guidance. Cross-­ sectional images should be acquired promptly after injection [28]. CT arthrography may be used to further evaluate the knee after trauma. In patients with contraindications for MRI, it may be used as an alternative. In the acute fracture, CT arthrography is used to evaluate underlying degenerative changes including meniscal and ligament tears, cartilage loss, subchondral cysts, sclerosis, and osteophytes [29]. Direct MR arthrography can also be used for further evaluation after knee trauma. It is particularly useful in the postoperative setting to evaluate menisci and cartilage. It may help to differentiate a meniscal tear or insufficient stitching from degenerative meniscal changes [23].

2.2.3 Summary In acute knee trauma, accurate diagnosis and visualization of knee fractures are vital for optimal treatment strategies. While plain radiography still remains the most important imaging modality in the primary diagnosis, cross-sectional imaging techniques including CT and MRI have become indispensable. In the emergency department setting, CT is usually easily accessible and images are rapidly acquired. However, radiation dose needs to be limited to a minimum. CT facilitates preoperative planning in more complex cases. It is particularly advisable to perform CT scans in complex tibial plateau fractures to minimize postoperative complications. CT is also helpful in the postoperative follow-up of patients with knee fractures. Additional application of contrast media can depict vessel status in severe cases.

26

In contrast to CT, MRI is much more time-­ consuming, often not readily accessible, and expensive. Nevertheless, MRI has great advantages in the depiction of soft tissue structures and cartilage. Thus, it has often become a good alternative to diagnostic knee arthroscopy in the primary assessment of knee trauma. MRI can also give a clue to the injury mechanism by evaluation of the marrow oedema. Knowledge of the injury mechanism aids in the detection of accompanying soft tissue injuries, e.g. rupture of the cruciate ligaments. MRI may also detect fractures that are occult even in CT scans. Furthermore, MRI is needed in the postoperative follow-up of patients, particularly in search of postoperative complications. In special cases, cross-sectional imaging techniques (CT and MRI) may be complemented by arthrography. Direct application of contrast media into the joint aids in the primary detection of meniscal and ligament tears and also in the postoperative follow-up.

References 1. Fagan DJ, Davies S.  The clinical indications for plain radiography in acute knee trauma. Injury. 2000;31(9):723–7. 2. Stiell IG, et  al. Implementation of the Ottawa Knee Rule for the use of radiography in acute knee injuries. JAMA. 1997;278(23):2075–9. 3. Bohndorf K, Kilcoyne RF. Traumatic injuries: imaging of peripheral musculoskeletal injuries. Eur Radiol. 2002;12(7):1605–16. 4. Daffner RH, Tabas JH. Trauma oblique radiographs of the knee. J Bone Joint Surg Am. 1987;69(4):568–72. 5. Gray SD, et al. Acute knee trauma: how many plain film views are necessary for the initial examination? Skelet Radiol. 1997;26(5):298–302. 6. Newberg AH, Greenstein R.  Radiographic evaluation of tibial plateau fractures. Radiology. 1978;126(2):319–23. 7. Mustonen AO, Koskinen SK, Kiuru MJ. Acute knee trauma: analysis of multidetector computed tomography findings and comparison with conventional radiography. Acta Radiol. 2005;46(8):866–74. 8. Spratt J, Salkowski L, Weir J, Abrahams P. Imaging atlas of human anatomy. Philadelphia, PA: Elsevier; 2010. 9. European Commission, Directorate-General for the Environment. Radiation protection 118: referral guidelines for imaging. Luxembourg: European Commission, Directorate-General for the Environment; 2000.

T. Zahel and H. Einhellig 10. Moore TM, Harvey JP Jr. Roentgenographic measurement of tibial-plateau depression due to fracture. J Bone Joint Surg Am. 1974;56(1):155–60. 11. Rogers LF.  Radiology of skeletal trauma. 2nd ed. New York: Churchill Livingstone; 1992. 12. Mauch F, Drews B.  Magnetresonanz- und Computertomographie. Unfallchirurg. 2016;119:790–802. 13. Alkadhi H, Leschka S, Stolzmann P, Scheffel H. Wie funktioniert CT? Berlin: Springer; 2011. 14. Huber-Wagner S, et al. Effect of whole-body CT during trauma resuscitation on survival: a retrospective, multicentre study. Lancet. 2009;373(9673):1455–61. 15. Stengel D, et al. Dose reduction in whole-body computed tomography of multiple injuries (DoReMI): protocol for a prospective cohort study. Scand J Trauma Resusc Emerg Med. 2014;22:15. 16. Markhardt BK, Gross JM, Monu JU. Schatzker classification of tibial plateau fractures: use of CT and MR imaging improves assessment. Radiographics. 2009;29(2):585–97. 17. Weil YA, et  al. Posteromedial supine approach for reduction and fixation of medial and bicondylar tibial plateau fractures. J Orthop Trauma. 2008;22(5):357–62. 18. Wild M, Windolf J, Flohé S.  Patellafrakturen. Unfallchirurg. 2010;5:401–12. 19. Wicky S, et  al. Comparison between standard radiography and spiral CT with 3D reconstruction in the evaluation, classification and management of tibial plateau fractures. Eur Radiol. 2000;10(8):1227–32. 20. Goutallier D, et  al. Influence of lower-limb torsion on long-term outcomes of tibial valgus osteotomy for medial compartment knee osteoarthritis. J Bone Joint Surg Am. 2006;88(11):2439–47. 21. Weishaupt D, Köchli VD, Marincek B. Wie funktioniert MRI? Berlin: Springer; 2014. 22. Wörtler K.  MRT des Kniegelenkes. Radiologe. 2007;47:1131–46. 23. Wörtler K.  MRT des Kniegelenks nach Kreuzbandund Meniskusoperationen. Radiologie up2date. 2009;9(01):67–81. 24. Prokop A, et al. [Multislice CT in diagnostic work-up of polytrauma]. Unfallchirurg. 2006;109(7):545–50. 25. Friemert B, et  al. Diagnosis of chondral lesions of the knee joint: can MRI replace arthroscopy? A prospective study. Knee Surg Sports Traumatol Arthrosc. 2004;12(1):58–64. 26. Wolf K.  Bildgebende Verfahren und Strahlenschutz in der Unfallchirurgie. Unfallchirurg. 1996;99(11):889–900. 27. Carter K, et al. Ultrasound detection of patellar fracture and evaluation of the knee extensor mechanism in the emergency department. West J Emerg Med. 2016;17(6):814–6. 28. Kassarjian A. Current concepts in MR and CT arthrography. Semin Musculoskelet Radiol. 2012;16(1):1–2. 29. Kijowski R, et  al. Imaging following acute knee trauma. Osteoarthr Cartil. 2014;22(10):1429–43.

3

Epidemiology and Classification of Distal Femur Fractures Lukas Negrin

3.1

Epidemiology of Distal Femur Fractures

Distal femur fractures are rare and severe injuries. In 2000, they accounted for 0.4% of all fractures in children and adults of all ages [1, 2], whereas a proportion of 0.6% was reported for the time period 1937–1956 and of 4.7% for the time period 1894–1937 [3]. In regard to adults (aged ≥16  years), with 4%, the rate of distal femur fractures in all femur fractures remained the same in the last 30–40 years [4, 5]. Their incidence, however, increased from 5.1/100000/year [5] to 7/100000/year until 2011 [4]. As Table 3.1 reveals, a classic bimodal distribution with a peak in frequency in young men as well as in women at an advanced age has been detected [5–8].

3.1.1 D  istal Femur Fractures in the Elderly and Super-Elderly 55.2% of all adult distal femur fractures occurred in the age group 65 plus (elderly) and 36.8% in the age group 80 plus (super-elderly) [3]. Furthermore, distal femur fractures comprised 0.9% of all fractures in the elderly and 1.2% of all L. Negrin (*) Department of Orthopedics and Trauma-Surgery, Medical University of Vienna, Vienna, Austria e-mail: [email protected]

fractures in the super-elderly with a proportion of 83% and 86%, respectively, for females [3]. Accordingly, a rate of 87% for females was reported in patients older than 60 years by Kolmert and Wulff [5]. Of males, an incidence of 8.4/100000/years and 20.1/100000/years was calculated for elderly and super-elderly, respectively. The equivalent incidences for females were 30.1/100000/year and 64.0/100000/year [3, 9]. Most of the distal femur fractures in the age groups 65 plus and 80 plus occurred after moderate trauma due to osteoporosis [5, 7]. In the elderly (super-elderly), 95.2% (96.4%) of the distal femur fractures were provoked by low-energy injuries secondary to falls [3]. Therefore, associated injuries and considerable soft tissue damage were rarely found in both age groups [10]. Alarmingly, a fourfold increase of osteoporotic distal femur fractures within 30 years was revealed [11]. Most recently, a periprosthetic proportion of 52.2% was detected in patients of 60  years or older [12]. Distal femur fractures were the most common periprosthetic fractures [13] and the second most frequent fragility fractures of the femur, following those of the hip [14]. Based on 44,511 primary and 3222 revision total knee arthroplasties, performed in the time period 1997–2008, an incidence of distal femur fractures of 0.6% (1.3%) 5 years (10 years) postoperatively was reported for primary procedures and of 1.7% (2.2%) for revision procedures [15], with the majority occurring in the supracondylar region [16, 17].

© Springer Nature Switzerland AG 2021 M. Hanschen et al. (eds.), Knee Fractures, Strategies in Fracture Treatments, https://doi.org/10.1007/978-3-030-81776-3_3

27

Publication Observation First author year period Kolmert 1982 1969–1976 [5] Arneson 1988 1965–1984 [6] Martinet 2000 1980–1989 [7] Court-­ 2006 2000 Brown [1] Ng [8] 2012 1984–2007 24 201

UK

USA

2165

USA

Switzerland

123

Origin Sweden

>0

≥12

>0

>0

Patient Number of age (years) fractures 137 ≥16

Table 3.1  Epidemiology and demographic data

10–19

About 20

5–24

Peak Male (years) ≤20

80–89

About 70 >75

≥75

Peak Female (years) 61–80

64.7

62.5

37.6

73.1

66.7

48.5

60.2

38.3

42.0

Severe Older than Female trauma (%) 50 years (%) (%) 84.0 73.0 38.0

8.2

4.5

11.7

Incidence (n/100000/ year) 5.1

3%

6%

Proportion of femoral fractures (%) 4%

28 L. Negrin

3  Epidemiology and Classification of Distal Femur Fractures

3.1.2 D  istal Femur Fractures in the Younger Adult Population

29

terms supracondylar/intracondylar or metaphyseal/epiphyseal, by their pattern (transverse, oblique, spiral), as well as by their displacement, angulation, and comminution. The clas44.8% of the distal femur fractures (55.0% in sification of distal femur fractures is presented men and 38.5% in women) arose in the 16–65 differently in the literature. Whereas Chiron age group [3]. They were usually caused by high-­ and coworkers [24] and Stewart and coworkers energy trauma [1], such as road traffic accidents, [25] divided these fractures into unicondylar, mainly car and motorcycle accidents (53–74%) supracondylar, and intercondylar (T-fractures), [7, 18, 19], or falls from significant heights (13– Neer and coworkers [26] omitted the first two 20%) [18, 19]. As a result of the excessive applied groups. force, many patients with distal femur fractures 3.2.1.1 Neer Classification suffered severe concomitant injuries [18, 20]. In 1967, Neer and coworkers [26] published a simple classification scheme of supracondylar-­ intracondylar femoral fractures, subdividing 3.1.3 Pediatric Distal Femur them into the following categories: minimal Fractures displacement (grade I); displacement of the Distal femur fractures were detected in 0.3% of condyles (grade II), including medial (IIA) pediatric patients younger than 16 years (2000) [2] and lateral (IIB) displacement; and concomiand in 1.1% of pediatric patients up to 17 years of tant supracondylar and shaft fractures (grade age (2009–2011) [21]. They amounted to 11.7% III). Due to the fact that this classification sys[22] (1998–2001) and 24.6% [21] (2009–2011) of tem does not provide much clinical and progall femur fractures in children and adolescents with nostic information to the surgeon it was rarely a maximum age of 17  years. However, steadily used. improved diagnostic tools might be one reason for these diverging findings. Regarding the patient 3.2.1.2 Seinsheimer Classification population evaluated from 2009 to 2011, 28.1% of In 1980, Seinsheimer [27] published a more the distal femur fractures were rated epiphyseal; detailed system. Type I denotes non-displaced they accounted for 0.3% of all fractures [21]. fractures (with less than 2  mm displacement of According to Eid and Hafez [23], the highest fre- the fractured fragments). Type II includes fracquency of distal epiphyseal fractures has to be tures involving only the distal metaphysis, withexpected in adolescents, with males at greater risk out extension into the intracondylar region, than females. Older children and adolescents pre- distinguishing between two-part fractures (type dominately sustain distal femur fractures via high- IIA) and comminuted fractures (type IIB). Type energy mechanisms (motor vehicle collisions, III comprises fractures involving the intercondypedestrians struck by cars, and sports accidents), lar notch in which one or both condyles are sepawhereas high-energy falls and child abuse are the rate fragments (type IIIA–IIIC). Finally, type IV fractures extend through the articular surface of leading causes for infants and toddlers [22]. the femoral condyles. They combine medial condyle fractures (type IVA), lateral condyle fractures (type IVB), and comminuted fractures (type 3.2 Classification IVC). Although the Seinsheimer Classification 3.2.1 Classification of Fracture describes the fracture pattern in a more detailed Pattern way, it did not become popular because it was not Clinically, distal femur fractures are usually user-friendly and provided minimal information described due to their location denoted by the on prognosis.

L. Negrin

30

3.2.1.3 AO/OTA Classification of Distal Femur Fractures The AO/OTA Classification of distal femur fractures, part of the AO/OTA Fracture and Dislocation Classification [28, 29], is graphically displayed in Fig. 3.1. It focuses on the involved anatomic region (designated as 33) and on the fracture pattern that inherently depends on the energy of the injury, considering all fractures within the trans-epicondylar width of the knee and even prognosticating the outcome. Based on the documentation of thousands of these fractures, the AO/OTA Classification of distal femur fractures distinguishes among extra-articular injuries (type A); partial articular injuries (type B), meaning parts of the articular surface remain in contact with the diaphysis of the femur; and complete articular injuries (type C) with both condyles being detached from the diaphysis. Each of these three categories is further divided into three groups by the degree of comminution. The 33-A1 subgroup includes fractures with a simple metaphyseal component, 33-A2 includes wedge fractures in the metaphysis, and 33-A3 includes fractures with a complex metaphyseal involvement. 33-B1 denotes partial articular fractures of the lateral condyle in the sagittal plane, 33-B2 partial articular fractures of the medial condyle in the sagittal plane, and 33-B3 partial articular fractures of the medial or lateral femoral condyle in the frontal plane (Hoffa fractures). Finally, the 33-C1 subgroup comprises supracondylar/intercondylar femur fractures with a simple metaphyseal component and simple splits, 33-C2 comprises supracondylar/intercondylar femur fractures with a complex metaphyseal compo-

nent and simple articular fragments, and 33-C3 comprises supracondylar/intercondylar femur fractures with complex articular fragments. Noteworthy, in progressing from A to C, the severity of the fracture increases, whereas the probability for a good result decreases. The same applies for the progression from 1 to 3 within each group. As the AO/OTA Classification of distal femur fractures is useful to guide treatment including the surgical approach and fracture implants, it has become widely used and accepted by trauma surgeons worldwide [30].

3.2.2 Classification of Soft Tissue Damage The extent of fracture-associated soft tissue injury is an intrinsic component of any fracture because it may create an exceptionally unfavorable environment for bone healing and thus represents an important factor for surgical decision-making and intraoperative tactics.

3.2.2.1 Tscherne and Oestern Classification The classification by Tscherne and Oestern [31] is a frequently referenced system for defining soft tissue injuries [32]. It differentiates between the two main fracture groups open (O) and closed (C). In each category, soft tissue injuries are grouped into four categories according to increasing severity (Table 3.2). The relationship between the severity of injuries rated by this system and long-term outcomes has been documented [33].

33 distal 33-A1

33-A2

33-A3

33-A extraarticular fracture 33-A1 Simple 33-A2 metaphyseal wedge and/or fragmented wedge 33-A3 metaphyseal complex

33-B1

33-B2

33-B3

33-B partial articular fracture 33-B1 lateral condyle, sagittal 33-B2 medial condyle, sagittal 33-B3 coronal

33-C1

33-C2

33-C3

33-C complete articular fracture 33-C1 articular simple, metaphyseal simple 33-C2 articular simple, metaphyseal multifragmentary 33-C3 articular multifragmentary

Fig. 3.1  AO/OTA Classification of distal femur fractures (reproduced from www.aofoundation.org)

3  Epidemiology and Classification of Distal Femur Fractures

31

Table 3.2  Classification of soft tissue injuries according to Tscherne Grade 0 I II III

IV

Open soft tissue injuries Fr. O 1—Skin lacerated by bone fragment, no or minimal skin contusion, negligible contamination Fr. O 2—Skin laceration with circumferential skin or soft tissue contusion and moderate contamination Fr. O 3—Extensive soft tissue damage, major vessel and/or nerve injury, compartment syndrome, severe contamination

Closed fractures Fr. C 0—No or minor soft tissue injury Fr. C 1—Superficial skin contusion or abrasion to the skin Fr. C 2—Deep contaminated abrasions and localized skin or muscle contusions Fr. C 3—Extensive skin contusion, destruction of muscle or subcutaneous tissue avulsion, degloving injury, compartment syndrome, vascular injury

Fr. O 4—Subtotal and total amputations (separation of all important anatomical structures, remaining soft tissue bridge less than 1/4 of the circumference of the limb)

Of interest, the Tscherne and Oestern grading is the only classification system for soft tissue injuries associated with closed fractures [33].

3.2.2.2 Gustilo and Anderson Classification Gustilo and Anderson [34] developed their classification of open fractures on the basis of an analysis of 1025 cases. They initially described three types: fractures with a clean wound of less than 1 cm in size with little or no contamination (type I), fractures with a skin laceration longer than 1  cm and surrounding tissues presenting with no flaps and avulsions (type II), and fractures with extensive soft tissue damage, frequently with compromised vascularity with or without severe wound contamination (type III). Due to the fact that clinical application revealed many different factors in severe fractures, Gustilo, Mendoza, and Williams [35] introduced the subgroups IIIA, IIIB, and IIIC, denoting adequate soft tissue coverage of the fractured bone (IIIA), extensive soft tissue loss with periosteal stripping and bone exposure, usually associated with massive contamination (IIIB), and concomitant major vascular injury requiring repair (IIIC). This system uses the amount of energy, the extent of soft tissue injury, and the extent of contamination for determination of fracture severity. Progression from grade I to IIIC implies a higher degree of energy involved in the injury, higher soft tissue and bone damage, and higher potential for complications.

The Gustilo and Anderson grading has become the most commonly used system for classifying open fractures [36]. Its parameters allow therapeutic conclusions, its simplicity makes it prone for the use in clinical routine, and its subgroups allow forecasting of possible complications, which increase with increasing classification number [36].

3.2.3 Classification of Periprosthetic Fractures The classification systems presented in Sect. 3.2.1 do not include the prosthesis stability and the bone quality that are both crucial for determining treatment strategy. Thus, specific systems have been developed for periprosthetic fractures.

3.2.3.1 Rorabeck Classification By subdividing periprosthetic fractures into three categories, according to the characteristics of the femoral component of the total knee arthroplasty the Rorabeck Classification [37, 38], which is graphically displayed in Fig.  3.2, takes fracture displacement and implant stability into account. Type I is assigned to a non-displaced distal femur fracture (less than 5 mm of displacement and less than 5° of angulation) around a well-fixed prosthesis. Type II denotes displaced fractures (≥5  mm displacement or ≥5° angulation) with the prosthesis remaining stable. These fractures are subdivided into type IIA (non-comminuted)

L. Negrin

32

a

b

c

d

Fig. 3.2  Rorabeck Classification. (a) Type I, (b) type II, (c and d) type III

and type IIB (comminuted). Finally, undisplaced or displaced fractures around a loose prosthesis are assigned to category IIIA and IIIB, respectively. Due to significant bone loss, these frac-

tures require a prosthetic replacement with stable fixation of the stem in the central part of the femur. The Rorabeck Classification is the most commonly used grading system for peripros-

3  Epidemiology and Classification of Distal Femur Fractures

thetic fractures [39]. Its main advantage is its simplicity. Nevertheless, it does not deal with the quality of the bone stock (e.g., osteoporosis), loosening prior to injury, the underlying implant, the fracture type, or whether there is an ipsilateral arthroplasty of the hip in situ. All these factors have to be considered when planning fracture fixation or replacement.

3.2.3.2 Unified Classification System The Unified Classification System (UCS) [40], a standardized grading system of periprosthetic fractures, was recently presented by the AO Foundation. It can be used to describe any periprosthetic fracture independently of the body region. Additionally, it provides a principles-­ based and pragmatic guide to fracture management [40, 41]. In general, there are six basic fracture characteristics (A–F), allocated to six, further subdivided into regions (I–VI), including the knee (V) [42]. Corresponding to the AO/OTA Fracture and Dislocation Classification, the digit 3 is allocated to the distal femur. V.3-A denotes varus/valgus injuries, with V.3-A1 affecting the lateral and V.3-A2 the medial epicondyle. Category V.3-B refers to the bed of the implant. The subgroup V.3-B1 includes periprosthetic distal femur fractures proximal to the stable stem with good bone stock, V.3-B2 includes fractures proximal to the loose stem with good bone stock, whereas V.3-B3 refers to fractures proximal to the loose stem with poor bone stock or bone defect. V.3-C fractures are located proximal to the implant and cement mantle, whereas V.3-D fractures are located between hip and knee arthroplasties close to the knee. Finally, V.3-E

Fig. 3.3  Salter-Harris Classification

33

denotes fractures of the femoral condyles articulating with a tibial hemiarthroplasty [42]. Field testing of the UCS has revealed substantial inter-observer reliability and almost perfect intra-observer reliability when applied to periprosthetic fractures in association with total knee arthroplasty in the hands of experienced and inexperienced users [43].

3.2.4 Classification of Pediatric Fractures The epiphysis is the weakest area in children’s anatomy. Identifying and accurately diagnosing physeal fractures are crucial for adequate treatment in order to minimize the possibility of growth disturbances and angular growth deformities.

3.2.4.1 Salter-Harris Classification for Distal Femoral Epiphyseal Fractures In 1963, Salter and Harris proposed a five-stage system classifying fractures according to the involvement of the physis, metaphysis, and epiphysis [44], which is presented in Fig.  3.3. Subsequently, six rarer types (VI [45] and VII–IX [46]) have been added. Type I denotes transverse fractures through the physis without an associated fracture through the adjacent epiphysis or metaphysis. Type II is characterized by fractures through the physis with an extension of the fracture line into a corner of the adjacent metaphysis, sparing the epiphysis. Type III includes fractures through the growth plate and epiphysis, separat-

L. Negrin

34

ing a part of it from the metaphysis. Common to type IV is a sagittal fracture line that extends from the metaphyseal cortex down to the physis and enters the epiphysis. Type V fractures are crush or compression type injuries that involve only the growth plate without a fracture of either the diaphysis or epiphysis, resulting in a decrease in the perceived space between the epiphysis and metaphysis on X-ray. The Salter-Harris Classification has been considered a useful tool in estimating both the prognosis and the potential for growth disturbance [47]. It has gained widespread acceptance throughout the world [48].

3.2.4.2 AO Pediatric Comprehensive Classification of Long-Bone Fractures To achieve a common understanding when dealing with long bone fractures in children and adolescents, the AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF) was introduced and evaluated in 2007 [49, 50] according to a three-phase concept proposed by Audigé and coworkers [51]. The overall structure of the PCCF is based on fracture localization and morphology [50, 52]. The latter is documented by a specific child code (1–9) that indicates the fracture pattern. The numbering of bones and their segments is similar to that of the AO/OTA Fracture and Dislocation Classification, but it was adapted specifically for the needs of the growing skeleton. Furthermore, the PCCF rates severity in two categories, simple (1), with two main fracture segments, and multifragmentary (2) [50, 52]. In general, internationally known and accepted fracture patterns in children are considered. Pediatric distal femur fractures are classified by a four-digit or five-digit code. The code starts with 33, denoting the bone and the segment, followed by the subsegment (M, metaphyseal; E, epiphyseal), a subsegment-specific child pattern digit, and (if applicable) the grade of severity. In case of ligament avulsions, the letter m (medial) or l (lateral) is appended to indicate the affected side. Three fracture patterns have been identified

for distal metaphyseal fractures of the femur (Fig. 3.4). Torus fractures (M/2), also known as buckle fractures, are incomplete fractures, defined as a compressive plastic deformation of the bony cortex on one side while the opposite cortex remains intact [53]. Complete fractures (M/3) involve the entire cross section of the bone, whereas avulsion fractures (M/7) indicate a separation of a small fragment of bone cortex at the site of ligament attachment. Patterns of epiphyseal fractures include the categories I–IV according to Salter and Harris [44] (using the child codes E/1–E/4), ligament avulsions (E/7), and flake fractures (E/8) with a small osteochondral fragment dislodged from the articular surface (Fig. 3.5). In an a retrospective cohort study of 2716 patients [54] focusing on an epidemiological evaluation of pediatric long bone fractures, the PCCF system was successfully used for fracture classification and appeared to be especially comprehensive for metaphyseal and epiphyseal lower extremity fractures [55].

3.3

Concomitant Injuries in High-Energy Trauma

A distal femur fracture in non-osteoporotic bone is the result of axial loading with varus, valgus, or torsional high-energy forces, exerted on the flexed knee [20, 56]. Not surprisingly, in most trauma victims, these forces produce additional injuries both in the same extremity and to other body regions. Although one fifth of distal fractures are supposed to occur as an isolated injury in trauma victims [57, 58], associated injuries have been reported in up to 95% [18, 59, 60]. Noteworthy, polytrauma was sustained by 28–48% [18, 20, 57, 61–63].

3.3.1 Ipsilateral Injuries Due to the excessive force, 14–27% [20, 60, 61, 64, 65] of the individuals, who suffered a distal

3  Epidemiology and Classification of Distal Femur Fractures

35

Fig. 3.4  AO Pediatric Comprehensive Classification of distal metaphyseal fractures (reproduced from www.aofoundation.org)

femur fracture, sustained additional fractures in the ipsilateral leg. In detail, there were femoral shaft fractures in 4–5% [18, 66], intertrochanteric femur fractures in 4% [66], and tibia fractures in 5–23.3% [18, 67–69]. The patella was involved in 5–19% [18, 20, 57, 68, 70, 71] and injuries to the ankle and to the foot occurred in 5% [68] and 8% [71], respectively. Upper limb injuries were found in 2% [60]. As a result of the high-energy mechanism, pelvic fractures were fairly common as well (18–42% [65, 72]). Ligamentous injuries to the knee were detected in 10–30% [20, 68, 70, 71, 73], mostly affecting the anterior cruciate ligament [70]. Lesions of the menisci were observed in 4–12% [64, 67, 71] and flake fractures in 7% [64]. Additionally, individuals suffering distal femur fractures often sustained considerable soft tissue damage [73, 74]. A pro-

portion of 23% [63] was reported for soft tissue injuries in general and of 20% [64] for closed soft tissue injuries in particular. 5–10% [56, 59] of distal femur fractures were open injuries. The open wound was usually located above the anterior thigh proximal to the patella, causing damage to the quadriceps muscle and extensor mechanism [56]. Neurovascular injuries were rare; nevertheless they have to be ruled out a priori [20]. With 0.2–10% [20, 25, 59, 72], the incidence of vascular injuries was not assessed consistently. Nerve injuries accounted for 1–5% [18, 20, 72]. Very limited data are available for concomitant injuries to pediatric epiphyseal distal femur fractures. Ligament injuries were reported in 37.5% [75], peroneal nerve palsy occurred in 7.3% [23], and vascular impairment in 2.6% [23].

L. Negrin

36

Fig. 3.5  AO Pediatric Comprehensive Classification of distal epiphyseal fractures (reproduced from www.aofoundation.org)

3.3.2 I njuries in Other Body Regions

References

In general, fractures of the contralateral leg were reported in 8–33.4% [60, 65, 76]. With 5% [68] and 10% [69], detailed data are solely available for femoral shaft fractures and tibial fractures. The proportion of fractures affecting the upper limb ranged from 5 to 33% [60, 65, 66, 68]. Chest injuries were found in 5–83% [65, 68, 72]. Abdominal injuries were detected in 18–58% [65, 72] and spine fractures in 4–25% [65, 71, 72], whereas the incidence of head injuries accounted for 10–42% [65, 68, 72]. Finally, with regard to pediatric epiphyseal distal femur fractures, visceral injuries and concomitant skeletal injuries were detected in 4.6% and 13.9%, respectively [23].

1. Court-Brown CM, Caesar B.  Epidemiology of adult fractures: a review. Injury. 2006;37(8):691–7. 2. Rennie L, Court-Brown CM, Mok JY, Beattie TF. The epidemiology of fractures in children. Injury. 2007;38(8):913–22. 3. Court-Brown CM, Bugler KE. Epidemiology of fractures in the elderly. In: Court-Brown C, McQueen M, Swiontkowski MF, Ring D, Friedmann SM, Duckworth AD, editors. Musculoskeletal trauma in the elderly. Boca Raton: CRC Press; 2016. 4. Davidson E, Court-Brown CM.  Distal femoral fractures. In: Court-Brown C, McQueen M, Swiontkowski MF, Ring D, Friedmann SM, Duckworth AD, editors. Musculoskeletal trauma in the elderly. Boca Raton: CRC Press; 2016. 5. Kolmert L, Wulff K. Epidemiology and treatment of distal femoral fractures in adults. Acta Orthop Scand. 1982;53(6):957–62. 6. Arneson TJ, Melton LJ 3rd, Lewallen DG, O’Fallon WM. Epidemiology of diaphyseal and distal femoral

3  Epidemiology and Classification of Distal Femur Fractures fractures in Rochester, Minnesota, 1965–1984. Clin Orthop Relat Res. 1988;(234):188–94. 7. Martinet O, Cordey J, Harder Y, Maier A, Bühler M, Barraud GE. The epidemiology of fractures of the distal femur. Injury. 2000;31(Suppl 3):C62–3. 8. Ng AC, Drake MT, Clarke BL, Sems SA, Atkinson EJ, Achenbach SJ, Melton L Jr. Trends in subtrochanteric, diaphyseal, and distal femur fractures, 1984– 2007. Osteoporos Int. 2012;23(6):1721–6. 9. Court-Brown CM, Clement ND, Duckworth AD, Aitken S, Biant LC, McQueen MM.  The spectrum of fractures in the elderly. Bone Joint J. 2014;96-B(3):366–72. 10. Neubauer T, Krawany M, Leitner L, Karlbauer A, Wagner M, Plecko M.  Retrograde femoral nailing in elderly patients: outcome and functional results. Orthopedics. 2012;35(6):e855–61. 11. Kannus P, Niemi S, Palvanen M, Parkkari J, Pasanen M, Järvinen M, Vuori I. Continuously rising problem of osteoporotic knee fractures in elderly women: nationwide statistics in Finland in 1970–1999 and predictions until the year 2030. Bone. 2001;29(5):419–23. 12. Streubel PN, Ricci WM, Wong A, Gardner MJ.  Mortality after distal femur fractures in elderly patients. Clin Orthop Relat Res. 2011;469(4):1188–96. 13. Ebraheim NA, Kelley LH, Liu X, Thomas IS, Steiner RB, Liu J.  Periprosthetic distal femur fracture after total knee arthroplasty: a systematic review. Orthop Surg. 2015;7(4):297–305. 14. Nieves JW, Bilezikian JP, Lane JM, Einhorn TA, Wang Y, Steinbuch M, Cosman F. Fragility fractures of the hip and femur: incidence and patient characteristics. Osteoporos Int. 2010;21(3):399–408. 15. Meek RM, Norwood T, Smith R, Brenkel IJ, Howie CR. The risk of peri-prosthetic fracture after primary and revision total hip and knee replacement. J Bone Joint Surg Br. 2011;93(1):96–101. 16. Kim KI, Egol KA, Hozack WJ, Parvizi J. Periprosthetic fractures after total knee arthroplasties. Clin Orthop Relat Res. 2006;446:167–75. 17. Whitehouse MR, Mehendale S.  Periprosthetic fractures around the knee: current concepts and advances in management. Curr Rev Musculoskelet Med. 2014;7(2):136–44. 18. Bedes L, Bonnevialle P, Ehlinger M, Bertin R, Vandenbusch E, Piétu G, SooFCOT. External fixation of distal femoral fractures in adults’ multicentre retrospective study of 43 patients. Orthop Traumatol Surg Res. 2014;100(8):867–72. 19. Nagla A, Manchanda A, Gupta A, Tantuway V, Patel V, Arshad N.  Study to evaluate the outcomes of surgical stabilization of distal 1/3rd fracture shaft femur with retrograde nailing. Int J Res Orthop. 2017;3(1):96–102. 20. Schütz M, Kääb MJ.  Distale Femurfrakturen. In: Haas NP, Krettek C, editors. Tscherne Unfallchirurgie Hüfte Oberschenkel. Berlin: Springer; 2012. 21. Audigé L, Slongo T, Lutz N, Blumenthal A, Joeris A.  The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF). Part III: multifrag-

37

mentary long bone fractures in children—a retrospective analysis of 2,716 patients from 2 tertiary pediatric hospitals in Switzerland. Acta Orthop Scand. 2017;88(2):133–9. 22. Rewers A, Hedegaard H, Lezotte D, Meng K, Battan FK, Emery K, Hamman RF.  Childhood femur fractures, associated injuries, and sociodemographic risk factors: a population-based study. Pediatrics. 2005;115(5):e543–52. 23. Eid AM, Hafez MA. Traumatic injuries of the distal femoral physis. Retrospective study on 151 cases. Injury. 2002;33(3):251–5. 24. Chiron HS, Tremoulet J, Casey P, Muller M. Fractures of the distal third of the femur treated by internal fixation. Clin Orthop Relat Res. 1974;100:160–70. 25. Stewart MJ, Sisk TD, Wallace S.  Fractures of the distal third of the femur. J Bone Joint Surg Am. 1966;48:784–807. 26. Neer CS 2nd, Grantham SA, Shelton ML.  Supracondylar fracture of the adult femur. A study of one hundred and ten cases. J Bone Joint Surg Am. 1967;49(4):591–613. 27. Seinsheimer F 3rd. Fractures of the distal femur. Clin Orthop Relat Res. 1980;(153):169–79. 28. Müller ME, Koch P, Nazarian S, Schatzer J. The comprehensive classification of fractures of long bones. Berlin: Springer; 1990. 29. Foundation AO.  AO/OTA fracture and dislocation classification 2014. Available from https://aotrauma. aofoundation.org/Structure/education/self-­directed-­ learning/reference-­materials/classifications/Pages/ao-­ ota-­classification.aspx 30. Berner A, Schütz M.  Distal Femur Fractures. In: Oestern HJ, Trentz O, Uranues S, editors. Bone and joint injuries: trauma surgery III.  Berlin: Springer; 2014. 31. Tscherne H, Oestern HJ.  A new classification of soft-tissue damage in open and closed fractures. Unfallheilkunde. 1982;85(3):111–5. 32. Ibrahim DA, Swenson A, Sassoon A, Fernando ND.  Classifications in brief: the tscherne classification of soft tissue injury. Clin Orthop Relat Res. 2017;475(2):560–4. 33. Dirschl DR, Cannada LK. Classification of fractures. In: Rockwood CA, Green DP, Bucholz RW, editors. Rockwood and Green’s fractures in adults. 7th ed. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins; 2010. p. 39–52. 34. Gustilo RB, Anderson JT.  Prevention of infec tion in the treatment of one thousand and twentyfive open fractures of long bones: retrospective and prospective analyses. J Bone Joint Surg Am. 1976;58:453–8. 35. Gustilo RB, Mendoza RM, Williams DN. Problems in the management of type III (severe) open fractures: a new classification of type III open fractures. J Trauma. 1984;24(8):742–6. 36. Kim PH, Leopold SS.  In brief: Gustilo-Anderson classification. [corrected]. Clin Orthop Relat Res. 2012;470(11):3270–4.

38 37. Lewis PL, Rorabeck CH. Periprosthetic fractures. In: Engh GA, Rorabeck CH, editors. Revision total knee arthroplasty. Baltimore: Williams & Wilkins; 1997. p. 275–95. 38. Rorabeck CH, Taylor JW. Classification of periprosthetic fractures complicating total knee arthroplasty. Orthop Clin North Am. 1999;30(2):209–14. 39. Yoo JD, Kim NK.  Periprosthetic fractures following total knee arthroplasty. Knee Surg Relat Res. 2015;27(1):1–9. 40. Duncan CP, Haddad FS. Classification. In: Schutz M, Perka C, Ruedi TP, editors. Periprosthetic fracture management. Stuttgart: Georg Thieme Verlag; 2013. p. 47–89. 41. Duncan CP, Haddad FS.  The Unified Classification System (UCS): improving our understanding of periprosthetic fractures. Bone Joint J. 2014;96-B(6):713–6. 42. Duncan CP, Haddad FS. Unified classification system. AO Foundation. 2015. Available from: www.aofoundation.org/legal 43. Van der Merwe JM, Haddad FS, Duncan CP. Field testing the Unified Classification System for periprosthetic fractures of the femur, tibia and patella in association with knee replacement: an international collaboration. Bone Joint J. 2014; 96-B(12):1669–73. 44. Salter RB, Harris WR. Injuries involving the epiphyseal plate. J Bone Joint Surg Am. 1963;45(3):587–622. 45. Rang M.  The growth plate and its disorders. Baltimore: Williams and Wilkins; 1969. 46. Ogden JA.  Skeletal growth mechanism injury patterns. J Pediatr Orthop. 1982;2(4):371–7. 47. Brown JH, DeLuca SA.  Growth plate injuries: Salter-Harris classification. Am Fam Physician. 1992;46(4):1180–4. 48. Peterson HA.  Epiphyseal growth plate fractures. Berlin: Springer; 2007. 49. Joeris A, Lutz N, Blumenthal A, Slongo T, Audigé L.  The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF). Part I: location and morphology of 2,292 upper extremity fractures in children and adolescents. Acta Orthop Scand. 2017;88(2):123–8. 50. Slongo TF, Audigé L, AO Pediatric Classification Group. Fracture and dislocation classification compendium for children: the AO pediatric comprehensive classification of long bone fractures (PCCF). J Orthop Trauma. 2007;21(10 Suppl):S135–60. 51. Audigé L, Bhandari M, Hanson B, Kellam J. A concept for the validation of fracture classifications. J Orthop Trauma. 2005;19(6):401–6. 52. Slongo T, Audigé L, AO Pediatric Classification Group. AO pediatric comprehensive classification of long-bone fractures (PCCF). AO Foundation. 2007. 53. Taylor-Butler KL, Landry GL.  Principles of heal ing and rehabilitation. In: Birrer RB, Griesemer B, Cataletto MB, editors. Pediatric sports medicine for primary care. Philadelphia: Lippincott Williams & Wilkins; 2002. p. 240.

L. Negrin 54. Joeris A, Lutz N, Wicki B, Slongo T, Audigé L. An epidemiological evaluation of pediatric long bone fractures—a retrospective cohort study of 2716 patients from two Swiss tertiary pediatric hospitals. BMC Pediatr. 2014;14:314. 55. Joeris A, Lutz N, Blumenthal A, Slongo T, Audigé L.  The AO Pediatric Comprehensive Classification of Long Bone Fractures (PCCF). Part II: location and morphology of 548 lower extremity fractures in children and adolescents. Acta Orthop Scand. 2017;88(2):129–32. 56. Collinge CA, Wiss DA.  Distal femur fractures. In: Bucholz RW, Heckman JD, Court-Brown CM, Tornetta 3rd. P, McQueen MM, Ricci WM, editors. Rockwood and Green’s fractures in adults. 7th ed. Philadelphia: Wolters Kluver; 2015. p. 1719–51. 57. Kinzl L.  Femur:Distal. In: Rüedi TP, Murphy WM, editors. AO principles of fracture management. Stuttgart New York: Thieme; 2000. p. 469–80. 58. Rüter A, Trentz O, Wagner M. Distales Femur. In: Rüter A, Trentz O, Wagner M, editors. Unfallchirurgie. München: Urban & Fischer; 2004. p. 1013–28. 59. Weight M, Collinge C. Early results of the less invasive stabilization system for mechanically unstable fractures of the distal femur (AO/OTA types A2, A3, C2, and C3). J Orthop Trauma. 2004;18(8):503–8. 60. Tailor A, Gajjar S, Mandalia M, Patel Y, Saxena S. Results of locking compression plates in fractures of distal end of femur. IJOS. 2017;3(1):360–3. 61. Schmit-Neuerburg KP, Hanke J, Assenmacher S. [Osteosynthesis of distal femoral fractures]. Chirurg 1989;60(11):711–722. 62. Erhardt JB, Vincenti M, Pressmar J, Kuelling FA, Spross C, Gebhard F, Roederer G.  Mid term results of distal femoral fractures treated with a polyaxial locking plate: a multi-center study. Open Orthop J. 2014;8:34–40. 63. Seifert J, Stengel D, Matthes G, Hinz P, Ekkernkamp A, Ostermann PA. Retrograde fixation of distal femoral fractures: results using a new nail system. J Orthop Trauma. 2003;17(7):488–95. 64. Tscherne H, Oestern H, Trentz O. Long term results of the distal femoral fracture and its special problems. Zentralbl Chir. 1977;102(15):897–904. 65. Khalil ALS, Ayoub MA.  Highly unstable com plex C3-type distal femur fracture: can double plating via a modified Olerud extensile approach be a standby solution? J Orthop Traumatol. 2012;13(4):179–88. 66. Motten T, Gupta R, Kalsotra N, Kamal Y, Mahajan N, Kiran U. The role of dynamic condylar screw in the management of fractures of the distal end of femur. Int J Orthop Surg. 2009;17(2):1–5. 67. Funovics PT, Vécsei V, Wozasek GE.  Mid- to long-­ term clinical findings in nailing of distal femoral fractures. J Surg Orthop Adv. 2003;12(4):218–24. 68. Aparajit P.  A study of management of supracondylar femur fractures by supracondylar nail. IJBABN. 2016;7(8):402–8.

3  Epidemiology and Classification of Distal Femur Fractures 69. Panchal P, Chintan Patel C, Poptani A. Treatment of distal end of fracture femur by locking compression plate. Int J Med Sci Public Health. 2015;5(9):1027–9. 70. Siliski JM, Mahring M, Hofer HP.  Supracondylar-­ intercondylar fractures of the femur. Treatment by internal fixation. J Bone Joint Surg Am. 1989;71(1):95–104. 71. Shafeed TP. Functional outcome of fixation of distal femoral fractures with DF-LCP: a prospective study. Int J Res Orthop. 2016;2(4):291–8. 72. Kovar FM, Jaindl M, Schuster R, Endler G, Platzer P.  Incidence and analysis of open fractures of the midshaft and distal femur. Wien Klin Wochenschr. 2013;125(13–14):396–401.

39

73. Walling AK, Seradge H, Spiegel PG.  Injuries to the knee ligaments with fractures of the femur. J Bone Joint Surg Am. 1982;64(9):1324–7. 74. Krettek C. Fractures of the distal femur. In: Heckman JD, Court-Brown CM, Tornetta P, Koval KJ, Bucholz RW, editors. Rockwood and Green’s fractures in adults: Rockwood, Green, and Wilkins’ fractures. 6th ed. Philadelphia: Lippincott Williams & Wilkins; 2006. 75. Bertin KC, Goble EM.  Ligament injuries associated with physeal fractures about the knee. Clin Orthop Relat Res. 1983;(177):188–95. 76. Yang RS, Liu HC, Liu TK. Supracondylar fractures of the femur. J Trauma. 1990;30(3):315–9.

4

Preoperative Planning in Distal Femur Fractures Adeel Aqil, Vivek Gulati, and James P. Waddell

4.1

Conservative Versus Surgical Treatment

Fractures of the distal femur are uncommon as they represent between 0.5 and 6% of all fractures and account for less than 3% of those affecting the femur [1, 2]. There is a bimodal distribution, with most commonly young men and older women being affected [1]. Nonoperative management options include the use of casting, traction, or a combination of both and have had some good results reported in the literature [3, 4]. Early studies even suggested that conservative was superior to operative management of these injuries [3–5]. However these older studies suffered from a selection bias where conservative treatment was more likely to occur in undisplaced fractures, and poorer techniques and implants for internal fixation were used in operative management. It is accepted that in general, casts are poorly tolerated and can result in pressure sores and joint stiffness [6]. Thus today, most of these fractures are treated surgically to prevent joint A. Aqil North Yorkshire Rotation, Northern Lincolnshire and Goole NHS Foundation Trust, London, UK V. Gulati (*) The London Clinic, London, UK J. P. Waddell Division of Orthopaedic Surgery, University of Toronto, Toronto, ON, Canada e-mail: [email protected]

stiffness, achieve early mobilization, and prevent complications associated with prolonged recumbency [7]. Having said this, nonoperative management may still have a role in selected cases, where patients are unfit for surgery or were already immobile prior to injury.

4.1.1 Periprosthetic Fractures of the Distal Femur The phenomenon of a periprosthetic distal femur fracture deserves special attention, as its management will obviously differ due to the presence of a knee replacement. There are more and more total knee replacements (TKRs) being performed each year worldwide. Whilst it is difficult to estimate the incidence of periprosthetic fractures, it stands to reason that their incidence will also be increasing. The literature suggests a periprosthetic fracture risk of between 0.2 and 2% following primary total knee replacement and an even higher rate following revision TKR procedures [8–11]. There is much in the literature discussing their management; however, treatment options are increasing with innovation. Most of these fractures occur following a low-­ energy fall and in elderly women [8, 12]. Other risk factors include inflammatory arthritis, chronic use of steroids, and osteopenia [13]. The phenomenon of femoral notching following TKR was initially thought to be a contributor, but now

© Springer Nature Switzerland AG 2021 M. Hanschen et al. (eds.), Knee Fractures, Strategies in Fracture Treatments, https://doi.org/10.1007/978-3-030-81776-3_4

41

A. Aqil et al.

42

is controversial, as a potential risk factor. Biomechanical studies seem to support its inclusion as a risk factor; however, clinical studies have demonstrated that most patients presenting with a fracture don’t actually have femoral notching [14, 15]. This is despite notching being quite common in asymptomatic patients with TKRs [9]. Traditionally, conservative management was the treatment of choice, which involved traction, casting, or a combination of both [16, 17]. However, non-weight bearing may be poorly tolerated, and prolonged recumbency was associated with high rates of pneumonia, pressure sores, and thromboembolic events [18, 19]. Mortality at 1-year has been documented to be 22%, with 9% of elderly patients having a late above knee amputation [18, 19]. This relatively high mortality rate means these patients are not dissimilar to those with a fracture of the proximal femur. The general consensus in fracture neck of femur patients is to operate, with the aim to allowing full immediate weight bearing in order to improve survival, and increase mobility, independence, and quality of life [20]. However internal fixation in this elderly group of patients is not without their complications. Poorer bone stock and the greater likelihood of grossly comminuted fractures mean that internal fixation is more likely to fail [21]. In the event of a fracture with a loose implant, revision or tumour prostheses have been used. These have the added advantage of allowing immediate weight bearing and an earlier restoration of function [22–24]. However their use involves resection of large amounts of bone, and failure may more likely result in amputation [25, 26]. Therefore, it is imperative that the most appropriate operative intervention be undertaken based on individual patient circumstances.

4.2

Timing of Surgical Treatment

Once surgical intervention has been decided upon, one should aim to undertake it as soon as possible to prevent medical deterioration of the patient from basal atelectasis, pneumonia, and venous stasis from immobility leading to throm-

boembolic events. However, one must also ensure that adequate planning has first been done to ensure the best possible outcome for the patient. This involves ensuring the patient is properly worked up for surgery and the relevant equipment and surgical team are available to perform the required operation. This may mean a delay of a couple of days but should not extend beyond a week. The exception is open fractures, which should be rushed to theatre early. However their operative management is very different from closed fractures and is done according to national and international guidelines [27].

4.3

Preoperative Planning

Planning is paramount and should consist of a history and examination followed by investigations. There are a number of salient points that should be considered in the history. Preoperative immobility and serious concomitant medical conditions may suggest nonoperative management might be more appropriate. For example, serious medical conditions, which significantly increase the risk of perioperative death or a history of malignancy with a short life expectancy, may indicate conservative management might be more suitable. Preoperative knee pain may give clues that the knee replacement was poorly functioning or even loose, suggesting that a revision procedure should be undertaken rather than fixation. Examination of the limb, which follows after excluding other more life-threatening injuries, should always commence with a neurovascular examination, followed by an inspection of the fracture site to ensure that the fracture is not open. Open fractures are managed using a completely different treatment algorithm in order to minimize the risk of infection and to maximize the chance of preserving the limb [27]. The skin should also be inspected carefully as patients with friable skin, such as those on long-term steroids, may develop significant skin tears, necrosis, and tissue loss if placed for any length of time in traction/plasters.

4  Preoperative Planning in Distal Femur Fractures

Further investigations, including plain orthogonal radiographs of the knee and entire femur, should follow, and a computed tomography (CT) scan of the distal femur may be appropriate to ascertain whether the fracture is intra-articular and to assess whether the knee replacement is well fixed or loose. Radiographs are also useful in assessing bone stock, which can aid decision-­ making as to which implant should be used if operative intervention is considered. If surgery is considered to be the best option, then it should aim to restore the mechanical alignment of the limb with a well-fixed and balanced knee replacement, if one is present, and in order to give the best chance of restoring function. Ideally one should try to aim to choose operative options, which allow immediate full weight bearing in order to reduce the chance of perioperative complications and a quicker restoration of quality of life.

4.3.1 Planning for Intramedullary Nailing of Distal Femoral Fractures Nailing of distal femoral fractures can be done ante- or retrograde. Antegrade nailing, however, may not bypass very distal fractures as the nail is unlikely to reach the most distal end of the femur. Furthermore, most antegrade nails have only two or three locking holes, at various distances from the tip of the nail. Thus the distal fragment is not as rigidly held as when a retrograde nail is used. Thus in general, retrograde nailing is preferred over antegrade nailing. Intramedullary nails provide relative fixation and thus fractures unite via secondary bone healing and callus formation. Thus open and absolute fracture reduction is not required if the fracture is extra-articular. In most circumstances, their use allows for early weight bearing and commencement of rehabilitation. They can be used effectively in simple or comminuted fractures. In isolation, they are generally not used with intra-articular fractures as displaced fractures should be reduced and internally fixed to prevent secondary bone healing and callus at the joint surface. Undisplaced fractures

43

also carry the risk of becoming displaced on insertion of the nail. One could consider open reduction and internal fixation with screws and then nailing the fracture, but this is extremely difficult when retrograde nailing, as the screws are likely to interfere with nail insertion. It may be possible to do this with long spiral fractures, which enter into the knee. In this circumstance, it may be possible to put screws across the femoral condyles to prevent fracture displacement prior to inserting an antegrade femoral nail. When selecting the nail diameter, one should try to ensure you chose the largest diameter that will be accommodated in the medullary canal. This provides more rotational stability to the construct. In turn this reduces stresses at the screw nail interfaces and those at the tip of the nail stem, thus reducing the risk of implant failure or periprosthetic fractures [28] (See Fig. 4.1). In very capacious canals, where adequate cortical fit cannot be achieved, or there is cortical thinning due to severe osteoporosis, additional cement can be used to provide increased nail rotational stability whilst allowing better purchase of locking screws [28]. However care should be taken that the fracture is well reduced and that cement does not leak out of the fracture site. Cement extrusion may lead to thermal damage of near-by soft tissues and prevent fracture healing by becoming interposed between the fracture ends. Therefore, under these circumstances and when using cement for additional fixation, we recommend that the fracture site is firstly exposed and secondly perfectly reduced and cabled, to inspect for and reduce the likelihood of cement escape. We would also recommend that pressurization of cement not be performed for the same reasons.

4.3.2 Planning for Intramedullary Nailing of Periprosthetic Distal Femoral Fractures Retrograde femoral nailing of these fractures has been reported to result in the highest rates of fracture healing [12]. This may be because fractures that lend themselves to this technique generally

A. Aqil et al.

44

Fig. 4.1  Distal femoral fracture treated with retrograde femoral nailing

have more distal bone stock or because the soft tissues around the fracture sites are less likely to be significantly disturbed during this type surgery. In addition, reaming of the femur generates bone graft and stimulation for fracture healing [28, 29]. Technically, retrograde femoral nailing of these fractures is similar to those without a TKR.  There are however a few caveats which should be borne in mind. Very few intra-articular fractures will have well-fixed TKR implants. Therefore if an intra-articular fracture is present, reconsider whether your implant is loose and whether a revision arthroplasty solution is more appropriate. In the event of an intra-articular fracture with a stable TKR, such as condylar fractures, which do not affect the implant cement mantle, condylar compression screws should be used to reduce fragments and prevent further comminution when inserting the nail. Care must be taken when placing these screws to avoid entering the knee joint or blocking the path for the insertion of the retrograde nail. Furthermore the use of a retrograde nail is only possible with cruciate sparing knee replacements and those with a wide enough intercondylar notch distance to allow a nail to pass. Posterior cruciate sacrificing TKRs have a closed box design preventing a nail from being used. In these

circumstances, plating and revision arthroplasty are the only surgical options available. It is imperative that post total knee radiographs, which have been taken prior to fracture, are studied carefully. A lateralized or flexed femoral component may make nail insertion impossible, as the notch will be eccentric to the longitudinal axis of the femur in the coronal or sagittal plane [30]. Slight flexion of the femoral component may not be deemed to be much of a problem initially but can be if the knee is very stiff and cannot flex to 90 degrees. Thus pre-fracture range of motion needs to be established and a gentle examination under anaesthesia of the knee is a good idea, prior to making ones incision. If the knee is found to be too stiff, then one should be prepared to plate the fracture instead (See Fig. 4.2). Another factor to consider is whether the patient has an ipsilateral total hip replacement or proximal intramedullary device. Retrograde nails have the additional risk of introducing stress risers between the tip of the nail and the stem of a hip replacement, which can result in further fractures. Therefore these inter-prosthetic fractures may be better managed with internal fixation using a robust plate which overlaps both implants [30] (See Fig. 4.3).

4  Preoperative Planning in Distal Femur Fractures

45

Fig. 4.2  Distal femoral periprosthetic fracture treated with retrograde femoral nailing

If you are fortunate enough to have a TKR, which can accommodate a nail passing through it, one must not forget about the polyethylene bearing and be prepared in case it needs to be replaced, prevents nail insertion, or becomes damaged. Therefore it is paramount that the brand of TKR is identified, the appropriate polyethylene extraction tools are obtained, and the full range of inserts are available should it need to be replaced and to achieve a balanced knee.

4.3.3 P  lanning for Internal Fixation of Distal Femoral Fractures There are a number of implant types available when internally fixing these fractures. However some of the older implant designs have largely been abandoned today. Angled blade plates, dynamic condylar screws, and condylar buttress

plates were either technically demanding to insert, weaker in construct, or had poor hold in the distal fragment [31]. Contemporary locking plates have been found to be biomechanically superior to non-locked designs and are responsible for the improvement of outcomes when performing internal fixation of these fractures [32]. They are designed to allow a submuscular insertion, thereby reducing tissue stripping around the fracture site. Screws are designed such that the heads are threaded and can lock into the plate. Thus, once all the screws are seated, the implant forms a fixed angle construct, which greatly increases its pull out strength and reduces the risk of implant failure in osteoporotic bone. A good working length should however be achieved between the fracture and nearest screw to allow for micro-motion of the fracture site and enable the best chance of bony union (See Fig. 4.3).

46

A. Aqil et al.

Fig. 4.3  Distal femoral fracture treated with a locking plate

4.3.4 P  lanning for Internal Fixation of Periprosthetic Distal Femoral Fractures Contemporary locking plates are far superior to non-locked designs and are responsible for the improvement of outcomes when performing internal fixation of these fractures [12, 33, 34]. If a cemented THR is present, proximal fixation can be achieved through bicortical screws, which go through the cement mantle. At the level of the stem, uni-cortical locking screws can be used or bicortical screws can also be used if one can squeeze them past the tapered tip of the stem. Cables can also provide additional fixation. Polyaxial locking plates, which allow screws to

be angled in different directions whilst still locking into the plate, are particularly useful when trying to navigate screws past femoral stems. Usefully these polyaxial plates sometimes have built-in holes to accommodate cables which prevent their displacement after insertion and when the patient commences rehabilitation (see Fig. 4.4). Cortical strut grafts provide initial stability and a matrix the body can use to bridge the fracture gap. However, an isolated cortical strut graft, cabled or wired at the fracture site, is insufficient in providing the required stability in these fractures [35]. A locking plate is still required and an orthogonally placed strut graft may have a role in preventing fixation failure

4  Preoperative Planning in Distal Femur Fractures

47

Fig. 4.4  Distal femoral periprosthetic fracture treated with a locking plate

prior to fracture union. Certainly, non-locked plates should not be used for these types of fractures where one is undoubtedly faced with osteoporotic and deficient bone [12].

4.3.5 Planning for Revision Arthroplasty of Periprosthetic Distal Femoral Fractures For low-demand patients, and in the presence of poor femoral bone stock, ligamentous instability, or loose TKR implants, the revision arthroplasty is the ideal surgical treatment choice [25, 36]. In severe situations, a distal femoral replacement may even be indicated. The operative technique does not differ greatly whether a total knee replacement is present or not, as the distal femur is resected. The only real difference occurs when dealing with the proximal tibial component, which may be well fixed. Care must be taken to preserve as much bone as possible on the tibial side and when removing cement. These procedures are best undertaken by those with experience in using these endo-prostheses. In summary, unfortunately, the literature lacks strong enough evidence to determine whether locking plates, nails, or revision knee replace-

ments are best for treating these fractures. A meta-analysis of retrospective evidence attempted to shed light on this question but found no difference in union rates between the use of locking plates or retrograde femoral nails [12]. Thus, it seems prudent that treatment decisions are made based on the availability of expertise, equipment, and patient-related variables. As such, there is no panacea for treating these injuries, and they should be treated with the general principles of relieving pain, restoring function, whilst reducing the possibility of complications associated with prolonged immobility.

References 1. Court-Brown CM, Caesar B.  Epidemiology of adult fractures: a review. Injury. 2006;37(8):691. 2. Martinet O, Cordey J, Harder Y, Maier A, Buhler M, Barraud GE. The epidemiology of fractures of the distal femur. Injury. 2000;31(Suppl 3):C62. 3. Mooney V, Nickel VL, Harvey JP Jr, Snelson R. Cast-­ brace treatment for fractures of the distal part of the femur. A prospective controlled study of one hundred and fifty patients. J Bone Joint Surg Am. 1970;52(8):1563. 4. Chiron HS, Tremoulet J, Casey P, Muller M. Fractures of the distal third of the femur treated by internal fixation. Clin Orthop Relat Res. 1974;(100):160.

48 5. Neer CS 2nd, Grantham SA, Shelton ML.  Supracondylar fracture of the adult femur. A study of one hundred and ten cases. J Bone Joint Surg Am. 1967;49(4):591. 6. Seinsheimer F 3rd. Fractures of the distal femur. Clin Orthop Relat Res. 1980;153:169. 7. Smith JR, Halliday R, Aquilina AL, Morrison RJ, Yip GC, McArthur J, Hull P, Gray A, Kelly MB, Orthopaedic Trauma Society. Distal femoral fractures: the need to review the standard of care. Injury. 2015;46(6):1084. 8. Berry DJ. Epidemiology: hip and knee. Orthop Clin North Am. 1999;30(2):183. 9. Ritter MA, Thong AE, Keating EM, Faris PM, Meding JB, Berend ME, Pierson JL, Davis KE. The effect of femoral notching during total knee arthroplasty on the prevalence of postoperative femoral fractures and on clinical outcome. J Bone Joint Surg Am. 2005;87(11):2411. 10. Aaron RK, Scott R.  Supracondylar fracture of the femur after total knee arthroplasty. Clin Orthop Relat Res. 1987;(219):136. 11. Inglis AE, Walker PS. Revision of failed knee replacements using fixed-axis hinges. J Bone Joint Surg. 1991;73(5):757. 12. Herrera DA, Kregor PJ, Cole PA, Levy BA, Jonsson A, Zlowodzki M.  Treatment of acute distal femur fractures above a total knee arthroplasty: systematic review of 415 cases (1981–2006). Acta Orthop. 2008;79(1):22. 13. Figgie MP, Goldberg VM, Figgie HE 3rd, Sobel M.  The results of treatment of supracondylar fracture above total knee arthroplasty. J Arthroplast. 1990;5(3):267. 14. Zalzal P, Backstein D, Gross AE, Papini M. Notching of the anterior femoral cortex during total knee arthroplasty characteristics that increase local stresses. J Arthroplast. 2006;21(5):737. 15. Lesh ML, Schneider DJ, Deol G, Davis B, Jacobs CR, Pellegrini VD Jr. The consequences of anterior femoral notching in total knee arthroplasty. A biomechanical study. J Bone Joint Surg Am. 2000;82-A(8):1096. 16. Delport PH, Van Audekercke R, Martens M, Mulier JC.  Conservative treatment of ipsilateral supracondylar femoral fracture after total knee arthroplasty. J Trauma. 1984;24(9):846. 17. Hirsh DM, Bhalla S, Roffman M.  Supracondylar fracture of the femur following total knee replacement. Report of four cases. J Bone Joint Surg Am. 1981;63(1):162. 18. Butt MS, Krikler SJ, Ali MS. Displaced fractures of the distal femur in elderly patients. Operative versus non-operative treatment. J Bone Joint Surg Br. 1996;78(1):110. 19. Karpman RR, Del Mar NB.  Supracondylar femoral fractures in the frail elderly. Fractures in need of treatment. Clin Orthop Relat Res. 1995;(316):21. 20. British Orthopaedic Association. BOAST 1 guideline Version 2. Patients sustaining a fragility hip Fracture. 2012.

A. Aqil et al. 21. Giannoudis PV, Schneider E.  Principles of fixa tion of osteoporotic fractures. J Bone Joint Surg. 2006;88(10):1272. 22. Schmidt AH, Braman JP, Duwelius PJ, McKee MD. Geriatric trauma: the role of immediate arthroplasty. J Bone Joint Surg Am. 2013;95(24):2230. 23. Freedman EL, Hak DJ, Johnson EE, Eckardt JJ. Total knee replacement including a modular distal femoral component in elderly patients with acute fracture or nonunion. J Orthop Trauma. 1995;9(3):231. 24. Wakabayashi H, Naito Y, Hasegawa M, Nakamura T, Sudo A. A tumor endoprosthesis is useful in elderly rheumatoid arthritis patient with acute intercondylar fracture of the distal femur. Rheumatol Int. 2012;32(5):1411. 25. Pour AE, Parvizi J, Slenker N, Purtill JJ, Sharkey PF. Rotating hinged total knee replacement: use with caution. J Bone Joint Surg Am. 1735;89(8):2007. 26. Mortazavi SM, Kurd MF, Bender B, Post Z, Parvizi J, Purtill JJ. Distal femoral arthroplasty for the treatment of periprosthetic fractures after total knee arthroplasty. J Arthroplast. 2010;25(5):775. 27. British Orthopaedic Association. Boast 4 guideline. The management of severe open lower limb fractures. 2009. 28. Chen SH, Yu TC, Chang CH, Lu YC. Biomechanical analysis of retrograde intramedullary nail fixation in distal femoral fractures. Knee. 2008;15(5):384. 29. Gliatis J.  Periprosthetic distal femur fracture: plate versus nail fixation. Opinion: intramedullary nail. J Orthop Trauma. 2007;21(3):220. 30. Johnston AT, Tsiridis E, Eyres KS, Toms AD.  Periprosthetic fractures in the distal femur following total knee replacement: a review and guide to management. Knee. 2012;19(3):156. 31. Forster MC, Komarsamy B, Davison JN. Distal femoral fractures: a review of fixation methods. Injury. 2006;37(2):97. 32. Zlowodzki M, Williamson S, Cole PA, Zardiackas LD, Kregor PJ. Biomechanical evaluation of the less invasive stabilization system, angled blade plate, and retrograde intramedullary nail for the internal fixation of distal femur fractures. J Orthop Trauma. 2004;18(8):494. 33. Large TM, Kellam JF, Bosse MJ, Sims SH, Althausen P, Masonis JL. Locked plating of supracondylar periprosthetic femur fractures. J Arthroplast. 2008;23(6 Suppl 1):115. 34. Erhardt JB, Grob K, Roderer G, Hoffmann A, Forster TN, Kuster MS.  Treatment of periprosthetic femur fractures with the non-contact bridging plate: a new angular stable implant. Arch Orthop Trauma Surg. 2008;128(4):409. 35. Schmotzer H, Tchejeyan GH, Dall DM.  Surgical management of intra- and postoperative fractures of the femur about the tip of the stem in total hip arthroplasty. J Arthroplast. 1996;11(6):709. 36. Berend KR, Lombardi AV Jr. Distal femoral replacement in nontumor cases with severe bone loss and instability. Clin Orthop Relat Res. 2009;467(2):485.

5

External Fixation of Distal Femur Fractures Arindam Banerjee

5.1

Indications

The use of external fixators in distal femur fractures is relatively uncommon. Most surgeons would prefer a rigid internal fixation at the very onset of treatment with a device such as a plate or a nail or combination of screws and a plate. Only internal fixators can provide stability and reduction of intra-articular fragments for restoration of optimum joint function. However external fixators have a niche role to play, and their usage is invaluable in the management of some of these fractures. The indications of use are as follows: 1. Using an external fixator is often part of polytrauma management in patients with multiple musculoskeletal injuries. Such a patient may be unfit for immediate definitive surgery and may require damage control procedures (DCO) as a lifesaving option. This patient subgroup usually involves young male patients with femur fractures [1]. 2. Damage control procedures may also be necessary for polytrauma victims who have significant chest, abdominal, or head injuries and may require other lifesaving operations on an A. Banerjee (*) NH Narayana Multispeciality and Superspeciality Hospitals, Howrah, West Bengal, India Institute of Neurosciences, Kolkata, West Bengal, India

emergency basis. For such patients, the musculoskeletal system is a lesser injury and the external device may offer a bridging period by allowing relative stability of the limb fracture until the general condition of the patient is optimized [2]. 3. Sometimes femoral fractures are complex and are difficult to fix with internal implants only. In such cases, the external fixator can supplement and augment stability. The external fixator can be used up to 3 months if necessary or can be removed earlier if the fracture becomes ‘sticky’ which means that a reasonable amount of callus is seen in follow-up X-rays and relative stability has been achieved [3]. 4. Certain external fixators can be used independently (i.e. without ORIF supplementation) as well. The Ilizarov and hybrid frames (which follow the external fixator principle) are extremely versatile. Orthofix and Delta frames have often been used as they offer more stability than uniplanar frames such as the Hoffman fixator [4]. 5. Some open fractures are extremely contaminated. These are injuries seen with agricultural or industrial accidents. These wounds are vulnerable to uncontrollable infection and therefore not suitable for definitive internal fixation until the infection is fully under control. These are patients who would benefit from external fixation [5].

© Springer Nature Switzerland AG 2021 M. Hanschen et al. (eds.), Knee Fractures, Strategies in Fracture Treatments, https://doi.org/10.1007/978-3-030-81776-3_5

49

A. Banerjee

50

6. This is also true for patients with significant vascular injuries. It is important to remember that the popliteal artery is almost an end artery and injuries to it often require urgent reconstructive surgery to prevent an amputation. Vascular injuries are frequently a part of a complex femoral trauma, and the external fixator with its ease and speed of application can save valuable time to allow the vascular surgeon to do his work as soon as possible. It is very important to remember that in such a case the external fixator has to be placed in a plane which will not hamper vascular surgery. Placement of Schanz screws have to be done in close consultation with vascular colleagues. There is no consensus on which of these injuries orthopaedic or vascular should be done first and should be decided on a case-to-case basis dependent of skill availability and other logistic considerations. The principle generally followed in an ideal situation is dependent on the fracture geometry and the immediate vascular status of the limb. If features of acute ischemia are obvious—the vascular surgeon must restore circulation first. Otherwise it is better to deal with the fracture stability urgently so that the subsequent vascular reconstruction is protected. This is very important in grossly unstable fractures [6]. 7. Frontline military trauma often happens faraway from bigger army hospitals which would have the infrastructure to offer internal fixation in a sterile environment. The external fixator can be inserted in a field hospital allowing patient transfer. This decreases the pain of the patient as well as the danger of sending a patient away with an unstable femur fracture. Unstable femur fractures can cause secondary injuries during transfer such as fat embolism or ARDS [7]. 8. Distal femoral fractures are frequently associated with fractures of the proximal tibia. Proximal tibial fractures are often associated with internal degloving injuries. Extensive blistering and swelling is noted at or immediately after presentation. Such injuries are unsuitable for immediate internal fixation and

require a 2–3-week interval of leg elevation in a suitable splint before they can be considered for surgery. External fixators temporarily stabilize in the interim period. ORIF done immediately on a badly swollen limb is an invitation for infection and disaster [8]. 9. External fixation can also be used in compartment syndromes as a supplementation to fasciotomy [9]. Open fractures of a distal femur which are relatively clean are not a contraindication for immediate ORIF. This is different from fractures of the proximal tibia. The distal femur has a generous muscular cover with quadriceps anteriorly, hamstrings posteriorly, and the insertion of the adductors on the medial aspect [10].

5.2

Surgical Approach

Patients undergoing external fixation generally do not require surgical exposure or open reduction of the fracture. The Schanz screws are placed appropriately, and the reduction is attempted by indirect techniques either manually with traction or using the distraction device of the fixator. If the fracture is open, some local manipulation is permissible. Wound debridement should also be done. The surgical approach normally involves creating soft tissue tracts to access the bone for placement of the screw. A No. 11 blade is used to make a sharp cut down to the level of the bone through the fascia and other soft tissue envelopes. It is necessary to have a deep drill sleeve to protect the surrounding tissue from collateral damage of the rotatory movements of the drill. The drill should be sharp and care must be taken not to damage soft tissue and vital structures distal to the second cortex of the bone. For optimum external fixation, it is important to place close attention to detail involving: • Site of placement • Angle of placement • Plane of placement

5  External Fixation of Distal Femur Fractures

In order to do this, the surgeon must have a clear map in his mind of the local anatomy as well as the three-dimensional fracture geometry so that he can choose a safe corridor for the passage of the Schanz screw. The bridging device of the external fixator can then act as an effective stabilizing and distracting tool by effecting traction on the fracture through embedded Schanz screws.

5.2.1 S  ite of Placement of Schanz Screws A pair of Schanz screws should be placed proximal and distal to the fracture or fractures site. The distance of the screws should be placed at an optimum distance from the fracture(s): this depends on the type of definitive staged procedure being planned afterwards. If the placement is too far apart, the leverage and immobilization of the fracture will not be adequate. And conversely, if pin placement is too close to the fracture, it will impinge on the potential space reserved for implants for subsequent ORIF. Using the same area of the bone for implant fixation in both stages of surgery will increase infection rates and cause bone to mechanically weaken. Placing screws in drill holes previously occupied by Schanz screws will also lead to poor purchase in bone. It is better that the bone used for placement of screws and plates in definitive surgery is kept virginal [10]. The external fixation construct should not obstruct the surgical field of plastic or vascular surgeons who plan to operate subsequently.

5.2.2 Angle of Placement It is important to angle the Schanz screws in a way that it does damage important vascular structures around the fracture. Knowledge of the course of these arteries is essential in order to avoid injuring them.

51

The important structures to avoid are: Above the Knee • The femoral artery in the adductor canal • Large perforating branches of the femoral artery (difficult to avoid in every case) • The profunda femoral artery Since the arterial supply of the distal femur is antero-medial, the pins are normally placed in the lateral or antero-lateral aspect of the femur. The pins cannot be placed posteriorly as they will lie between the limb and the patient’s bed. This will lead to pain and severe discomfort. At the Knee • The popliteal artery. This is the main structure to keep in mind. It is virtually an end artery and damage to it will precipitate a surgical disaster such as an amputation. Below the Knee • The branches of the popliteal artery mainly the anterior and posterior tibial artery • The tibia-peroneal or TP trunk which is a short trunk and is the direct continuation of the popliteal artery of anterior tibial origin [11] (Figs. 5.1 and 5.2).

5.2.3 Plane of Placement • The external fixator used can be: –– Uniplanar –– Biplanar The exact construct depends on the stability requirements of the fracture geometry and duration the surgeon plans to keep the external fixator on for [12].

5.3

Case ‘External Fixation of Distal Femur Fractures’

The use of external fixators as a primary treatment for the problem of floating knees is rela-

A. Banerjee

52

Quadriceps femoris

Quadriceps femoris tendon

Femur

Suprapatellar bursa Bursa under lateral head of gastrocnemius

Prepatellar bursa Patella

Joint capsule Articular cartilage

Synovial membrane

Meniscus

Joint cavity Infrapatellar fat pad Superficial infrapatellar bursa Deep infrapatellar bursa

Tibia

Fig. 5.1  Anatomical structures around the distal femur

Fig. 5.2 Neurovascular structures around the distal femur

Popliteal artey

Common peroneal nerve

Saphenous nerve Superior lateral genicular artery

Tibial nerve

Superficial peroneal nerve

Deep peroneal (anterior tibial) nerve

5  External Fixation of Distal Femur Fractures

53

Fig. 5.3  Open clavicle fracture with chest injury

tively common. Similarly using external fixator in the early stages of a femoral shaft diaphyseal fracture is also standard practice. But finding an isolated distal femoral fracture which required external fixation is not easy. A 26-year-old male presented in December 2006 with an open clavicle (Fig. 5.3) as well as an open (Gustilo-Anderson grade I injury) comminuted distal femoral fracture (Fig. 5.4). There was also a cut injury to the neck. Open clavicle injuries are potentially serious injuries and are usually associated with life-threatening chest injuries as the clavicle is in close relationship to the subclavian vessels. Lung trauma and haemo-/ pneumothorax are frequent [13]. However in this case there were no major thoracic injuries. This patient underwent external fixation of the distal femoral fracture (Figs. 5.5, 5.6, and 5.7) as well as debridement of the thigh wound. The external fixator was later converted to ORIF after 4 weeks. However it is important to remember that even in the absence of life-threatening injuries, association with ARDS through metabolic insults is common. When a femur fracture is added to this injury and the victim is a young male adult, the risk is increased manifold. Therefore in this particular case, a decision was taken to use an external fixator for the initial

treatment until the general condition of the patient stabilized and the fracture of the clavicle was treated. The distal femur was subsequently fixed internally. Take-Home Message • Usage of external fixation as a primary or definite line of management is an uncommon procedure in isolated distal femoral fractures. Primary ORIF is more common. This is because the distal femur has generous muscle cover and most injuries are suitable for primary ORIF. • External fixation may be used as a first line of treatment for patients who have life-­ threatening injuries (DCO) or comorbidities or have major soft tissue or vascular problems. • External fixation has wider usage in distal femoral fractures associated with other injuries such as proximal tibial fractures (the floating knee) as a primary treatment. These injuries are usually converted to a secondary ORIF after 2–3 weeks or as soon as they are suitable for conversion. Acknowledgement and Thanks  The case report on the use of external fixator in distal femur fractures was provided by Dr. G.G. Kar from Calcutta, India.

54

Fig. 5.4  Distal femoral fracture

A. Banerjee

5  External Fixation of Distal Femur Fractures Fig. 5.5 Preoperative clinical image

Fig. 5.6  Application of external fixator after debridement

Fig. 5.7  Post-operative X-rays

55

56

References 1. Bedes L, Bonnevialle P, Ehlinger M, Bertin R, Vandenbusch E, Piétu G, SoFCOT. External fixation of distal femoral fractures in adults’ multicenter retrospective study of 43 patients. Orthop Traumatol Surg Res. 2014;100(8):867–72. 2. Nicola R. Early total care versus damage control: current concepts in the orthopedic care of polytrauma patients. ISRN Orthop. 2013;2013:329452. 3. Morshed S, Miclau T 3rd, Bembom O, Cohen M, Knudson MM, Colford JM Jr. Delayed internal fixation of femoral shaft fracture reduces mortality among patients with multisystem trauma. J Bone Joint Surg Am. 2009;91(1):3–13. 4. Ehlinger M, Ducrot G, Adam P, Bonnomet F. Distal femur fractures. Surgical techniques and a review of the literature. Orthop Traumatol Surg Res. 2013;99(3):353–60. 5. Copuroglu C, Heybeli N, Ozcan M, Yilmaz B, Ciftdemir M, Copuroglu E. Major extremity ­injuries associated with farmyard accidents. Sci World J. 2012;2012:314038. 6. Mavrogenis AF, Panagopoulos GN, Kokkalis ZT, Koulouvaris P, Megaloikonomos PD, Igoumenou V, Mantas G, Moulakakis KG, Sfyroeras GS, Lazaris A, Soucacos PN.  Vascular injury in orthopedic trauma. Orthopedics. 2016;39(4):249–59.

A. Banerjee 7. Pathak G, Atkinson RN. Military external fixation of fractures. ADF Health. 2001;2:24–8. 8. Muñoz Vives J, Bel JC, Capel Agundez A, Chana Rodríguez F, Palomo Traver J, Schultz-Larsen M, Tosounidis T. The floating knee: a review on ipsilateral femoral and tibial fractures. EFORT Open Rev. 2017;1(11):375–82. 9. Harwood PJ, Giannoudis PV, Probst C, Krettek C, Pape HC.  The risk of local infective complications after damage control procedures for femoral shaft fracture. J Orthop Trauma. 2006;20(3):181–9. 10. Micheau A, Hoa D. e-Anatomy 2017. SECTION Limbs. https://www.imaios.com/en/e-­Anatomy/ Limbs/Leg-­arteries-­bones-­3D 11. Carroll EA, Koman LA. External fixation and temporary stabilization of femoral and tibial trauma. J Surg Orthop Adv. 2011;20(1):74–81. 12. Höntzsch D, Gebhard F, Kregor P, Oliver C.  Ed. Colton C.  External fixator—distal femur—AO surgery reference. https://www2.aofoundation. org/.../04_Sj9CPykssy0xPLMnMz0vMAfGjzOKN_ A0M3. 13. Van Laarhoven JJ, Hietbrink F, Ferree S, Gunning AC, Houwert RM, Verleisdonk EM, Leenen LP. Associated thoracic injury in patients with a clavicle fracture: a retrospective analysis of 1461 polytrauma patients. Eur J Trauma Emerg Surg. 2016;45(1):59–63.

6

Nail Osteosynthesis of Distal Femur Fractures Steve Borland, Jeremy Hall, and Aaron Nauth

6.1

Introduction

These goals are most commonly achieved using internal fixation with either an intramedulFractures of the distal femur comprise approxi- lary nail or a distal femoral locking plate used as mately 4–5% of femoral fractures [1]. As with a bridge plating construct. This chapter focuses on many fractures, they have a bimodal distribution the use of intramedullary nails to treat fractures of with peaks in young patients who sustain high-­ the distal femur. Indications, approaches, and energy injuries and in elderly patients who sus- techniques are discussed, along with appropriate tain fragility fractures. In addition, periprosthetic postoperative management and the recognized fractures around the knee following total knee advantages and disadvantages of this technique. arthroplasty (TKA) are becoming increasingly common and most commonly involve the distal femur [2]. The vast majority of distal femur frac- 6.2 Indications tures are treated operatively, with nonoperative treatment reserved for undisplaced fractures or Nailing can be indicated for most OTA/AO type A non-ambulatory patients. (extra-articular) and type C (complete articular) Fractures of the distal femur should be treated fractures of the distal femur, including periprosaccording to general fracture principles. Intra-­ thetic fractures above a TKA [3]. These indicaarticular fractures require an anatomic reduction tions are similar to those for locked plating, with a performed via a direct, open approach with the goal few exceptions. Nails may be contraindicated in of absolute stability and primary bone healing. In specific settings such as the presence of hardware contrast, the metaphyseal and diaphyseal portions in the ipsilateral proximal femur (e.g., a total hip of the fracture are often reduced indirectly with the arthroplasty or proximal femoral nail), fractures aim of restoring length, alignment, and rotation with extensive articular comminution (type C3), while achieving relative stability and healing by fractures with too small a condylar segment to bridging callus (secondary bone healing). allow nailing (less than 6–7 cm), and, finally, periprosthetic distal femur fractures with a closed femoral box or stemmed femoral component. S. Borland Great North Trauma and Emergency Centre, Royal Victoria In contrast, there are a number of situations Infirmary, Newcastle Upon Tyne, United Kingdom where nailing of distal femur fractures may offer J. Hall · A. Nauth (*) specific advantages including fractures with subSt. Michael’s Hospital, University of Toronto, stantial shaft extension (Fig. 6.1), fractures assoToronto, ON, Canada ciated with an ipsilateral fracture of the femoral e-mail: [email protected] © Springer Nature Switzerland AG 2021 M. Hanschen et al. (eds.), Knee Fractures, Strategies in Fracture Treatments, https://doi.org/10.1007/978-3-030-81776-3_6

57

S. Borland et al.

58

a

b

c

Fig. 6.1 (a) Preoperative radiograph demonstrating a comminuted extra-articular fracture of the distal femur in a 64-year-old male involved in a high-speed motorcycle accident. (b and c) Intraoperative photographs demonstrating closed reduction of the fracture, starting guidewire insertion and placement of a 5 mm blocking screw

a

b

c

d

e

(red arrow) to correct coronal alignment. (d and e) Postoperative radiographs demonstrating anatomic alignment. Note the use of four multi-planar distal locking screws (including one locking condylar bolt) and a blocking screw (red arrows)

d

e

Fig. 6. 2 (a and b) Preoperative radiographs demonstrating a distal femoral shaft fracture, an intra-articular medial femoral condyle fracture, and an ipsilateral displaced femoral neck fracture in a 26-year-old male involved in a high-speed motorcycle accident. (c, d and e) Long-term follow-up radiographs demonstrating healing of all three fractures. The patient was treated with provisional lag

screw fixation of the medial femoral condyle via a medial parapatellar approach, followed by RIMN, further plate fixation of the medial femoral condyle, and finally, closed reduction and sliding hip screw fixation of the femoral neck fracture. Note the RIMN was ended below the lesser trochanter to allow passage of the proximal sliding hip screw into the femoral neck

neck (Fig. 6.2), floating knee injuries where distal femur fractures are combined with fractures of the ipsilateral tibia (see Fig.  6.3), open fractures (see Fig.  6.4), and situations where early weight-bearing is desired (see Fig. 6.5). Recent evolutions in the design of modern nails have allowed the indications for nailing of distal femur fractures to expand substantially. These include increasing the number of distal

locking screws, employing the use of oblique/ multi-planar distal locking screws, clustering of distal locking screws in the distal aspect of the nail, and the inclusion of locking condylar bolts (see Figs. 6.1, 6.3 and 6.4) or fixed angle locking screws. All of these modern design evolutions have served to improve fixation in small condylar segments or osteoporotic bone, thereby substantially expanding the indications for which a nail

6  Nail Osteosynthesis of Distal Femur Fractures

a

b

59

c

Fig. 6.3 (a, b and c) Preoperative radiographs and 3D CT scan reconstructions demonstrating a comminuted, intra-­ articular distal femur fracture and a proximal tibial shaft fracture (floating knee injury) in a 23-year-old male involved in a high-speed motorcycle accident. The distal femur fracture was an open injury (Gustilo grade 2). (d and e) Six-month postoperative radiographs demonstrat-

a

b

c

d

e

ing healing in anatomic alignment following RIMN of the femur fracture and antegrade nailing of the tibia fracture. Note the use of multiple anteroposterior and lateral to medial lag screws in the distal femur (red arrows), locking condylar bolts in the RIMN, and blocking screws in the proximal tibia (blue arrows)

d

e

f

Fig. 6.4 (a, b, c and d) Preoperative radiographs and 3D CT scan reconstructions demonstrating a comminuted, intra-articular distal femur fracture in a 32-year-old male involved in a high-speed motorcycle accident. The distal femur fracture was an open injury (Gustilo grade 3). (e and f) Postoperative radiographs demonstrating anatomic

reduction following RIMN. Note the use of two lateral to medial lag screws in the distal femur placed anterior and posterior to the nail (blue arrows), locking condylar bolts in the RIMN (white arrows), and a blocking screw to aid in coronal alignment reduction (red arrow)

can be used. These modern nails have offered improved biomechanics [4] and clinical outcomes [5].

recommend the use of a retrograde nail for several reasons. First, the use of a retrograde nail allows direct access to guidewire placement in the distal fragment which dramatically improves reduction and control of the distal fragment. Second, the use of retrograde nail is advantageous for intra-articular fractures, as articular reduction and nail start point can be achieved through the same approach. Third, retrograde nailing is performed with the patient supine and the leg placed over a radiolucent triangle which substantially improves the ability to perform a

6.3

 ntegrade vs Retrograde A Nailing

While it is technically possible to use an antegrade nail for distal femur fractures and recent series have described the use of specially designed antegrade nails for this purpose [6], we

S. Borland et al.

60

a

b

c

d

e

Fig. 6.5 (a and b) Intraoperative radiographs demonstrating an extra-articular distal femur fracture in a 72-year-old female following a low-energy fall. This patient had previously undergone fixation of a periprosthetic fracture of the proximal femur several years prior and had well-fixed hardware in situ. A short RIMN was chosen for treatment as it allowed for removal of the least amount of pre-existing hardware and facilitated early weight-bearing. Note the placement of the radiolucent tri-

angle at the apex of the fracture to correct extension of the distal fragment (blue arrow) and the ideal positioning of the starting guidewire (center of the intercondylar notch on the AP view and anterior to Blumensaat’s line on the lateral view). In addition, on the lateral intraoperative view, flexion of the knee to approximately 40 degrees to facilitate safe reamer passage can be appreciated. (c, d and e) Six-month postoperative radiographs demonstrating healing in anatomic alignment

closed reduction of the distal femur over antegrade nailing. Fourth, there is widespread availability of retrograde nails with the modern distal fixation options described above. Finally, retrograde nailing has a much stronger track record in the literature on the treatment of distal femur fractures [1, 3, 7, 8].

inserted using smaller, more minimally invasive incisions that better preserve fracture biology. Finally, locked plating has often resulted in constructs that are overly stiff and potentially impair secondary bone healing, leading to higher nonunion rates than nails [2, 7]. However, recent evolutions in surgical technique and implant design have sought to address this issue with locked plating [10–12]. Hoskins et al. recently published a retrospective review of locked plating versus retrograde intramedullary nailing (RIMN) for the treatment of distal femur fractures based on Australian registry data in 2016 [1]. They were able to analyze outcomes for 297 patients (195 treated with locked plating and 102 treated with RIMN). Their primary finding was a clinically relevant and statistically significant improvement in general health outcomes, on the basis of EuroQol-5 Dimensions (EQ-5D) scores at 6  months with RIMN being superior to locked plating. There was a trend toward improved EQ-5D scores at 1 year in the RIMN group as well, although the difference was no longer statistically significant. They also reported a significant reduction in angular deformity in the RIMN group. The authors concluded that RIMN may be a superior treatment to locked plating for fractures of the distal femur, although their study had several

6.4

Retrograde Nailing Versus Locked Plating of Distal Femur Fractures

There remains at the present time relative controversy with respect to the use of retrograde nailing versus locked plating for the management of distal femur fractures. As described above, the indications for both implants are generally similar. Locked plating likely has more versatility with respect to small distal fragments and accommodating pre-existing hardware [9]. In addition, reduction may be more difficult to achieve with retrograde nailing. However, retrograde nailing has several potential advantages. First, retrograde nailing has been shown to be biomechanically superior when modern nail implants are compared to locked plating constructs [4]. Second, nails function as a load-sharing device that facilitates early weight-bearing. Third, nails can be

6  Nail Osteosynthesis of Distal Femur Fractures

limitations based on its retrospective nature, and this diminished the strength of their conclusions. However, the authors did feel that their results strongly supported the need for a randomized trial comparing RIMN to locked plating. In 2013, Tornetta et al. presented the results of a prospective randomized trial comparing 156 patients with extra or intra-articular fractures of the distal femur randomized to either locked plating (80) or RIMN (76) [13]. Treatment with a RIMN demonstrated trends toward improved functional outcomes and quality of life, although the observed differences failed to reach statistical significance, despite being above the threshold for clinical relevance. They also found that malunion in valgus >5° was more common with plate fixation. The results of this study, which represent the only level I evidence at present, suggest that overall there may be an advantage to RIMN over locked plating for the treatment of extra-­ articular or simple intra-articular fractures of the distal femur. In a recent meta-analysis from 2018, Koso et al. reported on the issue of plating versus retrograde nailing of distal femur fractures [8]. They combined the results from 11 studies, including a total of 505 patients (376 treated with plate fixation and 129 treated with RIMN). The authors found no significant differences in nonunion, malunion, complications, or revision surgery rate between the two groups. The authors concluded that based on their findings, both treatments were acceptable for distal femur fractures and the choice of implant could be based upon surgeon preference, patient factors, and specific fracture characteristics. In 2014, Ristevski et al. completed a systematic review on the treatment of periprosthetic distal femur fractures [2]. The authors compared locked plating to RIMN in 418 patients (308 treated with locked plating ant 110 treated with RIMN). There were no significant differences in nonunion or secondary surgical procedures, although there was a trend toward increased rates of nonunion with locked plating (8.8% with locked plating versus 3.6% with RIMN). In contrast, the rate of malunion was significantly lower with locked plating (7.6% with locked plating

61

versus 16.4% with RIMN). The authors concluded that results failed to indicate which was the preferred technique overall, and they felt there was a strong need for a prospective randomized trial comparing locked plating to RIMN for the treatment of periprosthetic distal femur fractures. Overall, the current evidence does not strongly support one technique over the other with respect to the use of RIMN versus locked plating for the management of distal femur fractures. On this basis, the selection of a nail versus a plate can be made at the discretion of the surgeon, while taking into account specific fracture pattern, surgical experience, and patient factors.

6.5

Surgical Approaches and Reduction Techniques

The patient positioning for retrograde nailing is supine with the use of a radiolucent table or radiolucent extension. Often a bump or sandbag under the ipsilateral buttock or a side support is helpful to prevent external rotation of the limb. In select cases where obtaining appropriate length and rotation may be particularly challenging (i.e., a highly comminuted and/or segmental fracture), we will often position the patient completely flat and prepare and drape both limbs to allow length and rotation to be matched directly to the intact limb intraoperatively. A radiolucent triangle or gown pack is placed under the knee to allow knee flexion for nail entry and also to relax the gastrocnemius, which in combination with the pull of the extensor mechanism commonly results in extension of the distal fragment. The surgeon should check that appropriate fluoroscopic views can be obtained prior to prepping the patient. Surgical approach is dependent upon fracture characteristics. For extra-articular fractures (see Figs. 6.1 and 6.5), a 3 cm midline incision is created just below the inferior pole of the patella. The patellar tendon can subsequently be split or a medial parapatellar incision can be used. Often a portion of the fat pad is excised. This allows access to the distal femur for insertion of the starting guidewire. For intra-articular fractures

62

where reduction and fixation of intra-articular fracture lines must be performed (see Figs. 6.2, 6.3 and 6.4), a formal medial parapatellar or lateral parapatellar approach is used to allow visualization and fixation of the articular surface. The remainder of the approach generally consists of percutaneous incisions for placement of locking screws and/or bolts in addition to percutaneous reduction aids.

6.5.1 R  eduction and Nail Insertion (Extra-articular Fractures) In the case of extra-articular fractures, the fracture can frequently be reduced in closed fashion. We begin the procedure by obtaining a provisional reduction of the fracture. This generally consists of traction on the limb with flexion of the knee over a radiolucent triangle. It is critical to place the radiolucent triangle directly at the apex of the fracture to correct the extension of the distal fragment that commonly occurs due to the pull of the gastrocnemius (see Fig.  6.5). Varus/ valgus alignment can then be corrected with direct manipulation of the distal limb. An appropriate start point for the retrograde nail is then obtained. In the setting of distal femur fracture, the start point is critical and often dictates the quality of the reduction that is subsequently obtained. The guidewire should be placed in the center of the intercondylar notch on the AP view and just anterior to Blumensaat’s line on the lateral view (see Fig.  6.5). The trajectory of the starting guidewire should then match the alignment of the distal femur on both views. Once optimal guidewire position is confirmed, reaming over top of the guidewire is then performed with a starting reamer. A soft tissue protector should be used to protect the patellar tendon and patellar cartilage. Flexion of the knee to approximately 30–40 degrees facilitates this (see Fig. 6.5). Once the starting point has been reamed, a ball-tipped guidewire is placed into the distal femur and across the fracture, to the level of the lesser trochanter. At this point reduction of the fracture should be confirmed with anatomic restoration of length and alignment. If the closed techniques described above are insufficient to achieve this,

S. Borland et al.

further reduction aids are required. In our experience, this is often the case, particularly with more distal and comminuted fractures. A variety of percutaneous strategies that maintain the biological advantages of nailing can be employed including [14]: 1. Percutaneous application of bone hooks or ball spiked pushers 2. Schanz pins in the distal fragment and/or proximal fragment 3. Blocking or Poller screws (see Figs. 6.1 and 6.4) 4. Percutaneous reduction clamp placement We find the use of blocking screws to be an excellent method for aiding reduction when nailing distal femur fractures (see Figs. 6.1 and 6.4). These screws can be placed in either the proximal or distal fragment and should be positioned in such a fashion to direct the path of the nail and correct any malreduction (most commonly in the coronal plane for distal femur fractures). Their utility and application has been well described in the literature [15, 16]. It is critical that reaming is done (or redone) after placement of the blocking screw(s) (see Fig. 6.1). Our preference is to use the 5 mm screws that accompany the nail set, as they are more robust for reaming around, more reliable for aiding fracture reduction, and this precludes the need to open an additional set. Once reduction is achieved and confirmed, reaming over the ball-tipped guidewire is carried out in 0.5 mm increments until cortical fit (“chatter”) is achieved. We typically over-ream by 1.5 mm. Nail length is selected based on measurement for a nail that will end at or above the lesser trochanter. The exception of this would be when a femoral neck fracture is present, in which case we end the nail distal to the lesser trochanter to allow for the placement of fixation in the femoral neck with a sliding hip screw (see Fig. 6.2). The nail is then passed over the guidewire and impacted into position with care taken to ensure that the nail is countersunk at least 3–5 mm below the articular surface of the distal femur. Fluoroscopic assessment is once again used to confirm anatomic restoration of length and alignment in both planes with the nail in position. In our experience, it is

6  Nail Osteosynthesis of Distal Femur Fractures

not uncommon to require some adjustment of fracture reduction at this stage, despite a good initial reduction and a satisfactory starting point, particularly in more complex (distal and/or comminuted) fractures. This most commonly occurs in the coronal plane and is often best addressed with the aid of blocking screws (see Figs. 6.1 and 6.4). This requires removal of the nail, insertion of a well-positioned blocking screw, and repeat reaming, prior to re-­insertion of the nail. Once satisfactory reduction is achieved, distal locking screw insertion is performed using a targeting guide, with screws placed through percutaneous incisions. In the setting of distal femur fractures, multiple distal locking screws (ideally 3–4 multiplanar screws) should be placed [5]. We find the use of locking condylar bolts to be advantageous, particularly in very distal or intra-articular fractures where compression and optimal fixation in the condyles is desired (see Figs. 6.1, 6.3 and 6.4). There is both biomechanical and clinical literature supporting the use of locking condylar bolts in this setting [4, 17]. Once distal locking is complete, final confirmation of both rotation and length should be confirmed prior to proximal locking. Removal of the targeting guide at this stage facilitates this, as it allows the leg to be placed in full extension on the table. Confirmation of length and rotation can be confirmed by visualization of fracture reduction in more simple fracture patterns (see Figs. 6.4 and 6.5). However, in more comminuted fractures, ancillary techniques such as comparison of the lesser trochanter profile with the contralateral limb or free draping of the contralateral limb to allow direct intraoperative clinical comparison may be required (see Fig. 6.1). Once this is confirmed, proximal locking is done anterior to posterior using fluoroscopic guidance through a small anterior incision and blunt dissection through the rectus femoris. In our experience, these screws generally measure 35 mm in women and 40 mm in men [18]. The use of 1 versus 2 proximal locking screws can be done at the discretion of the surgeon based on fracture pattern and bone quality.

63

6.5.2 R  eduction and Nail Insertion (Intra-articular Fractures) Distal femur fractures with intra-articular extension that are treated with RIMN fixation require open and anatomic reduction of the joint surface with rigid fixation. We generally begin with reducing and fixing any coronally oriented fractures (“Hoffa fragment”) with anterior to posterior screws (see Fig.  6.3). We typically use 3.5 mm or 2.7 mm screws for this to minimize hardware crowding. We then reduce the two condyles together in an anatomic fashion with the aid of k-wires to manipulate the individual condyles and the placement of a large pointed reduction clamp. The condyles are then secured together with 3.5 mm lag screws placed from lateral to medial. Care must be taken to avoid the desired path of the retrograde nail when placing these screws, which can be technically demanding. We generally find there is sufficient room for at least one lag screw anterior and one posterior to the nail. Two lag screws are most often sufficient, particularly when locking condylar bolts are subsequently placed in the nail (see Fig. 6.4). Once the intra-articular fractures are anatomically reduced and rigidly fixed with lag screws, RIMN proceeds as outlined above. At the conclusion of retrograde nailing, the femoral neck should be screened radiographically to ensure there are no fractures. We always obtain a preoperative CT scan to look for any evidence of a femoral neck fracture in all young patients with high-energy femur fractures prior to operative planning for a RIMN.  Despite this, it remains imperative to screen the femoral neck at the conclusion of the nailing procedure. In addition, the limb should be examined to compare length, alignment, and rotation to the contralateral limb once all the drapes are removed and prior to waking up the patient. Finally, both distal pulse palpation and a ligamentous examination of the knee should be carried out.

S. Borland et al.

64

6.6

Postoperative Treatment

Analgesia, antibiotic prophylaxis, and deep vein thrombosis prophylaxis are all done as per standard of care following nailing of distal femur fractures. Postoperative weight-bearing is dependent upon fracture pattern and fixation. For extra-­ articular fractures (including periprosthetic fractures above a total knee arthroplasty), we generally allow immediate weight-bearing as tolerated (WBAT). This is especially important in geriatric patients with fractures of the distal femur. If there is intra-articular involvement of the weight-bearing surface, then we generally restrict weight-bearing to toe-touch for the first 6 weeks and then progress to WBAT. Irrespective of fracture pattern, immediate active and passive ROM of the knee is allowed without restriction. Routine clinical and radiographic follow-up is carried out at 6 weeks, 12 weeks, 6 months, and 1 year, with continued follow-up until complete clinical and radiographic healing. On occasion, patients develop symptoms at the site of locking screw insertion due to prominence. Once fracture healing is complete, these screws can be removed in the clinic under local anesthetic (for one or two simple screws) or as an outpatient surgical procedure (for multiple symptomatic screws or for locking condylar bolts). Nail removal is rarely required unless it is for revision surgery in the setting of non-union or infection.

6.7

Conclusions

Retrograde nailing represents an excellent option for the treatment of extra-articular and simple intra-articular fractures of the distal femur. In more complex and more distal fractures, retrograde nailing can be technically demanding, and advanced techniques to both obtain and maintain reduction are often required. However, nailing offers substantial benefits with regard to minimally invasive insertion, biomechanical strength, early weight-bearing, and the potential to improve union rates and decrease complications. For these reasons, retrograde nailing is our treatment of

choice for the treatment of most distal femur fractures. Further research further defining indications and comparing treatment outcomes between RIMN and locked plating is warranted.

References 1. Hoskins W, Sheehy R, Edwards ER, et  al. Nails or plates for fracture of the distal femur? Data from the Victoria Orthopaedic trauma outcomes registry. Bone Joint J. 2016;98-B(6):846–50. 2. Ristevski B, Nauth A, Williams DS, et al. Systematic review of the treatment of periprosthetic distal femur fractures. J Orthop Trauma. 2014;28(5):307–12. 3. Beltran MJ, Gary JL, Collinge CA.  Management of distal femur fractures with modern plates and nails: state of the art. J Orthop Trauma. 2015;29(4):165–72. 4. Wahnert D, Hoffmeier KL, von Oldenburg G, Frober R, Hofmann GO, Muckley T.  Internal fixation of type-C distal femoral fractures in osteoporotic bone. J Bone Joint Surg Am. 92(6):1442–52. 5. Toro-Ibarguen A, Moreno-Beamud JA, PorrasMoreno MA, Aroca-Peinado M, Leon-Baltasar JL, Jorge-­ Mora AA.  The number of locking screws predicts the risk of nonunion and reintervention in periprosthetic total knee arthroplasty fractures treated with a nail. Eur J Orthop Surg Traumatol. 2015;25(4):661–4. 6. Zhao Z, Li Y, Ullah K, Sapkota B, Bi H, Wang Y. The antegrade angle-stable locking intramedullary nail for type-C distal femoral fractures: a thirty four case experience. Int Orthop. 2018;42(3):659–65. 7. Thomson AB, Driver R, Kregor PJ, Obremskey WT.  Long-term functional outcomes after intra-­ articular distal femur fractures: ORIF versus retrograde intramedullary nailing. Orthopedics. 2008;31(8):748–50. 8. Koso RE, Terhoeve C, Steen RG, Zura R.  Healing, nonunion, and re-operation after internal fixation of diaphyseal and distal femoral fractures: a systematic review and meta-analysis. Int Orthop. 2018;42(11):2675–83. 9. Streubel PN, Gardner MJ, Morshed S, Collinge CA, Gallagher B, Ricci WM. Are extreme distal periprosthetic supracondylar fractures of the femur too distal to fix using a lateral locked plate? J Bone Joint Surg Br. 2010;92(4):527–34. 10. Ricci WM, Streubel PN, Morshed S, Collinge CA, Nork SE, Gardner MJ.  Risk factors for failure of locked plate fixation of distal femur fractures: an analysis of 335 cases. J Orthop Trauma. 2014;28(2):83–9. 11. Bottlang M, Fitzpatrick DC, Sheerin D, et al. Dynamic fixation of distal femur fractures using far cortical locking screws: a prospective observational study. J Orthop Trauma. 2014;28(4):181–8.

6  Nail Osteosynthesis of Distal Femur Fractures 12. Linn MS, McAndrew CM, Prusaczyk B, Brimmo O, Ricci WM, Gardner MJ.  Dynamic locked plating of distal femur fractures. J Orthop Trauma. 2015;29(10):447–50. 13. Tornetta P EK, Jones CB, Ertl, JP, Mullis B, Perez E, Collinge CA, Ostrum R, Humphrey C, Nork S, Gardner MJ, Ricci WM, Phieffer LS, Teague D, Ertl W, Born CT, Zonno A, Siegel J, Sagi CH, Pollak A, Schmidt AH, Templeman D, Sems A, MD18; Freiss DM, Pape HC. Locked plating versus retrograde nailing for distal femur fractures: a multicenter randomized trial. 2013 Annual meeting of the Orthopaedic trauma association; 2013; Phoenix, Arizona. 14. Virkus WW, Kempton LB, Sorkin AT, Gaski GE. Intramedullary nailing of periarticular fractures. J Am Acad Orthop Surg. 2018;26(18):629–39.

65 15. Stedtfeld HW, Mittlmeier T, Landgraf P, Ewert A. The logic and clinical applications of blocking screws. J Bone Joint Surg Am. 2004;86-A(Suppl 2):17–25. 16. Auston D, Donohue D, Stoops K, et al. Long segment blocking screws increase the stability of retrograde nail fixation in geriatric supracondylar femur fractures: eliminating the “bell-clapper effect”. J Orthop Trauma. 2018;32(11):559–64. 17. Garnavos C, Lygdas P, Lasanianos NG.  Retrograde nailing and compression bolts in the treatment of type C distal femoral fractures. Injury. 2012;43(7):1170–5. 18. Collinge CA, Koerner JD, Yoon RS, Beltran MJ, Liporace FA.  Is there an optimal proximal locking screw length in retrograde intramedullary femoral nailing? Can we stop measuring for these screws? J Orthop Trauma. 2015;29(10):e421–4.

7

Plate and Screw Osteosynthesis of Distal Femur Fractures Jose A. Canseco, Ivan J. Zapolsky, Priya S. Prakash, and Derek J. Donegan

7.1

Indications for Plate and Screw Fixation of Distal Femur Fractures

Distal femur fractures make up 8 cm superior to the femoral con-

dyles [15, 16], although newer nail designs allow their use in fractures more distal. Some hip arthroplasty stems may also prohibit intramedullary fixation of such fractures. If the knee prosthesis is loose as in the case of Rorabeck III fractures, revision TKA is the appropriate choice for fixation [14, 17]. In cases other than those described previously, plate and screw fixation vs revision of arthroplasty hardware are the options remaining [14]. Surgeon skill and familiarity with the surgical technique has a significantly larger effect of outcomes after plate and screw fixation of distal femur fractures as compared to intramedullary nail fixation [18]. It has been shown that the low-­ volume surgeon has comparable success rates with intramedullary nailing of distal femur fractures as compared to higher-volume surgeons with greater experience [19]. However, in the case of minimally invasive locked plating fixation of distal femur fractures, surgeon experience has a major moderating factor on patient outcomes [19]. Patients treated by less experienced surgeons have more variable and overall worse outcomes when compared to highly experienced surgeons using the same systems for treatment of similar fractures [20].

7.2

Choice of Implants for the Plate and Screw Fixation of Distal Femur Fractures

As discussed above, the nature—or classification—of the fracture at the distal femur will help guide the choice of fixation. For intra-articular fracture components, absolute stability with anatomic reduction of articular fragments is paramount, followed by applying absolute versus relative stability principles to the extra-articular fracture components depending on the fracture patterns [21]. Conventional plating, fixed-angle plates with or without additional screw fixation, and locked plate fixation are three major options [19, 22]:

7  Plate and Screw Osteosynthesis of Distal Femur Fractures

69

7.2.1 Conventional Plate Fixation Despite many technological advances in plate and screw engineering, there remain some fracture geometries, like simple medial condyle fractures and Hoffa fragments, which are best managed via interfragmentary compression screws supplemented with a plate and screws in a position where they provide neutralization or a buttress function (Fig. 7.1).

7.2.2 Fixed-Angle Plate Fixation As implied by the name, fixed-angle plates are implants that are “precontoured” with a constant

Fig. 7.2  Femur with extra-articular distal fracture and compression screw fixation with blade plate for neutralization. Image art by Ivan Zapolsky, MD

Fig. 7.1  Femur with medial condyle fracture and compression screw fixation supplemented by a conventional plate utilized as a buttress. Image art by Ivan Zapolsky, MD

angle between the plate blade or screw designed to fit the anatomy of the distal femur [4, 23] (Fig. 7.2). In most cases, they are used for simple fractures with metaphyseal comminution, extra-­articular fractures, fractures in the supracondylar/intercondylar region, or fractures involving only one femoral condyle [4, 21–23]. With the advent of fixed-angle plates, there is a significant improvement in the success of treatment of distal femur fractures [19]. There are two main variants of the fixed-angle plate, the blade plate, and the dynamic condylar screw/compression plate. Blade plates are stable, rigid, and fixed-angle constructs that provide compression at the site of fractures [4, 23]. One of the most commonly used blade plates is the 95° plate [19, 22]. Given the shape of the plate, once inserted laterally, it will provide medial compres-

70

J. A. Canseco et al.

sion due to the valgus nature of the femur’s articular surface [23]. In order to be effective, the blade must be positioned approximately 2 cm proximal to the femoral joint line along the diaphyseal axis of the femur and over the anterior half of the femoral condyles [23]. Although a very good fixation device, there are disadvantages to its use, particularly in osteoporotic bone or cyclic stress loading situations, and due to the extensive surgical exposure required for insertion and less than optimal ability to address coronal plane fracture lines [4, 23]. From the blade plate design, dynamic condylar screw/compression plates (DCS) evolved with ability to provide epiphyseal lag screw fixation for fracture compression, particularly when there are intercondylar fracture lines [4, 23] (Fig. 7.3). The advantage was the less-extensive exposure needed

and easier insertion technique [4, 23]. However, disadvantages are similar to the blade plate in terms of cyclic stress loading tolerance [4].

Fig. 7.3 Femur with medial condyle fracture and dynamic condylar screw fixation. Image art by Ivan Zapolsky, MD

Fig. 7.4  Femur with comminuted very distal fracture and locking bridge plate fixation. Image art by Ivan Zapolsky, MD

7.2.3 Locked Plate Fixation As designs evolved in plate fixation, the use of minimally invasive techniques became more popular. Within distal femur fracture fixation, this led to the use of precontoured locked plates [4, 24]. An advantage of locked plate fixation is that constructs provide improved stability, which is particularly important when addressing osteoporotic bone (Fig. 7.4). Specifically, by locking the screw directly on the plate, the stability of the construct becomes independent of the interaction between

7  Plate and Screw Osteosynthesis of Distal Femur Fractures

71

the bone and the plate—a feature of fixed-angle devices [23]. Not only does this improve stability but also spares the devitalization of periosteum beneath the plate [19, 23]. Locked plates tend to have a precontoured design so as to allow reduction during insertion; in other words, the plate can be used as a reduction tool in the form of a mold [19, 23]. Additional advantages of novel locked plate designs are their ability to be inserted open or via minimally invasive approaches, all dependent on fracture pattern, degree of articular involvement, and experience of the surgeon [23]. Generally, longer plates are preferred so as to distribute stress and strain over long lengths of fixation constructs [19, 23]. Nevertheless, as in fixed-angle devices, plate placement is of utmost importance, with locked plates ideally placed parallel to the bone cortex and close to bone on AP view and aligned on lateral views with the intramedullary femoral canal [19, 23]. It is important to note that modern plating techniques have developed the ability to combine fixed-angle device features with locked plating advantages, thus creating hybrid constructs [19, 23]. By locking certain screw holes and utilizing nonlocking screws in others, a hybrid fixation with advantages of both constructs can be achieved to dial in appropriate stability to fractures based on bone quality and fixation construct [23]. Additionally, by using same plates, one can provide improved mechanical performance under torsional loads, particularly when using polyaxial locked screw fixation [19, 23].

approaches are also possible and are generally modifications of the above approaches.

7.3

The medial approach should be strongly considered for the plating of fractures on the medial femoral condyle [21]. The interval is between the vastus medialis and sartorius muscles (Fig. 7.1). Vastus medialis is elevated and sartorius is generally retracted posteriorly to reveal the adductor magnus muscle and its insertion to the adductor tubercle. Adductor magnus can then be retracted posteriorly to reveal the distal femur [1, 21]. During this approach, care should be taken, as the neurovascular bundle comprising the superficial femoral artery (transitioning to popliteal artery),

Surgical Approaches to the Distal Femur for Plate and Screw Fixation

There are three main surgical approaches available for the insertion of plates for distal femur fracture fixation: (1) lateral, (2) medial, and (3) posterior approach [1, 4, 21, 25]. Some surgeons describe an anterior approach, which is usually a medial or lateral parapatellar approach and is discussed in the respective medial or lateral sections. Of note, minimally invasive submuscular

7.3.1 Lateral Approach A majority of distal femur fractures are addressed utilizing the lateral approach, usually combined with a lateral parapatellar arthrotomy (Fig. 7.1). This approach is particularly helpful if there is involvement of the articular surface and for the application of most plate constructs [1, 4, 21]. The approach involves the split of the iliotibial (IT) band in line with the skin incision, and the internervous plane between the vastus lateralis muscle and the lateral intermuscular septum overlaying the hamstring muscles [1, 25]. The vastus lateralis is elevated anteriorly which reveals the distal femur [1]; however, care should be taken with this maneuver, as the profunda femoris perforators lie in the region depending on the extent of proximal dissection. Perforators should be tied off carefully prior to continuing dissection. The minimally invasive modification generally involves an incision over the anterior half of the lateral femoral condyle in line with Gerdy’s tubercle over the joint line and through the IT band. If the incision is performed about the epicondyle, little vastus lateralis should be encountered, which is retracted anteriorly to expose the lateral aspect of the distal femur.

7.3.2 Medial Approach

J. A. Canseco et al.

72

Fig. 7.5  Approaches to the distal femur. Green, lateral; blue, medial; orange, posterior; (1) femur; (2) popliteal a. and v.; (3) sciatic n. (3a common peroneal n., 3b tibial n.); (4) great saphenous v.; (5) quadriceps tendon; (6) vastus medialis; (7) vastus lateralis; (8) biceps femoris; (9) semi-

membranosus/semitendinosus; (10) gracilis; (11) patella; (12) lateral head of gastrocnemius; (13) medial head of gastrocnemius; (14) patellar tendon. Image art by Ivan Zapolsky, MD

femoral vein, and sciatic nerve (transitioning to common peroneal and tibial nerves) is encountered just posterior to the femur and beneath the adductor magnus [21]. This approach can be modified to fit the standard medial parapatellar approach to the distal femur/knee, such as in total knee arthroplasty, to help in the exposure of intra-articular fracture fragments [1].

to distal, the sciatic nerve lies anterior to the biceps femoris, which runs in a medial to lateral course across the posterior thigh [25]. Therefore, for proximal posterior femur approaches, the biceps and sciatic should be retracted medially, whereas for more distal incisions, the biceps and sciatic should be retracted laterally [25] (Fig. 7.5).

7.3.3 Posterior Approach On rare occasions, a Hoffa fragment that is very posterior might need to be addressed. In these cases, a posterior approach to the knee is warranted for fragment fixation. The incision is centered midline at the popliteal fossa but is made in an S shape beginning proximal-laterally over the biceps femoris, then diagonally across the fossa and medial-distal over the medial gastrocnemius [25]. There is no formal interval, but once deep fascia is incised, extreme caution should be observed due to the number of important neurovascular structures encountered, including the tibial nerve medial and posterior to the semimembranosus and medial gastrocnemius, the common peroneal nerve lateral and posterior to the biceps femoris, and the popliteal artery and vein, both deep and medial to the tibial nerve [25] (Fig. 7.1). The approach can be extended proximally, with the important note that from proximal

7.4

Postoperative Course and Follow-Up After Plate and Screw Fixation of Distal Femur Fractures

Following plate and screw fixation of a distal femur fracture, a strict postoperative activity protocol is an important facet of success. Articular fractures require strict non-weight-bearing, while some types of fixation may allow weight-bearing immediately after surgery [26, 27]. Though rehabilitation after distal femur fractures has been poorly studied, literature suggests that postoperative protocols should include early mobilization and range of motion to reduce postoperative complications secondary to prolonged immobilization; low-force loading associated with immediate postoperative ROM has a beneficial effect on the healing of articular cartilage [3–5, 13, 26, 28]. Weight-bearing restrictions following plate and screw fixation of distal femur fractures depend on fracture geometry and patient factors. If the articular surface is involved in the fracture,

7  Plate and Screw Osteosynthesis of Distal Femur Fractures

73

a patient must have protected weight-bearing for 8–12  weeks with close follow-up and radiographic evidence of healing prior to advancement [26]. If the fracture is extra-articular, the surgeon should strive to provide a stable enough construct to allow a patient to be weight-bearing as tolerated immediately after surgery [18]. Provided that adequate length, alignment, and rotation were obtained, and the patient demonstrated minimal postoperative pain, immediate weight-­ bearing is recommended [18]. If the construct cannot provide this level of stability, a patient should be instructed to have protected weight-­ bearing. The patient may then be advanced after 6–8 weeks, as long as there is radiographic evidence of bone healing or callus formation [27, 29]. Gait training and knee motion with a hinged knee brace on postoperative day 1 with physical therapy has been shown to improve motion and

function [1]. Utilizing a continuous passive motion machine may be necessary for patients unable to ambulate or incapable of moving the knee [3, 30]. Full knee extension should be emphasized during rehabilitation to prevent flexion contracture [1].

Fig. 7.6  Initial injury films. Comminuted intra-articular fractures of the distal femur and proximal tibia are evident. This was an open injury; intra-articular gas can be

seen on AP and lateral images. Images courtesy of Derek Donegan, MD MBA

7.5

 linical Case: Plate C and Screw Fixation of a Distal Femur Fracture

A 24-year-old man was struck by an automotive, sustaining multiple injuries including an intra-­ articular distal femur fracture (Fig. 7.6). He was initially placed in a knee and ankle spanning external fixator (Fig.  7.7). The intra-articular component was addressed first through a medial parapatellar arthrotomy. Articular fragments were mobilized and reduced to form a single articular block. Once the articular block was

74

J. A. Canseco et al.

Fig. 7.7  Preoperative 3D ghost reconstruction of right femur utilizing CT images obtained following placement of a knee spanning external fixator. Images courtesy of Derek Donegan, MD MBA

restored, it was reduced as a unit back to the intact metadiaphysis utilizing the previously placed external fixation system and strategically placed bone clamps, restoring length, alignment, and rotation. An 18-hole variable angle curved condylar plate was placed on the lateral aspect of the femur in a submuscular fashion via a lateral approach. The plate was balanced and secured in

place using k-wires. The plate was then secured with a nonlocking screw distally, and nonlocking screw proximally, just distal to the lesser trochanter, to compress the plate to bone and restore coronal and sagittal planes. The plate was then further secured utilizing hybrid fixation with locking screws distally and nonlocking screws proximally (Figs. 7.8 and 7.9).

7  Plate and Screw Osteosynthesis of Distal Femur Fractures

Fig. 7.8  Postoperative x-ray images of the distal and diaphyseal femur demonstrating restoration of distal femoral length alignment and rotation with anatomic reduc-

75

tion of the articular block. Images courtesy of Derek Donegan, MD MBA

Fig. 7.9  Postoperative x-ray images of the proximal femur demonstrating plate and screw placement. Anterior-­ posterior (left). Cross table lateral (right). Images courtesy of Derek Donegan, MD MBA

References 1. Gwathmey FW, Jones-Quaidoo SM, Kahler D, Hurwitz S, Cui Q.  Distal femoral fractures: current concepts. J Am Acad Orthop Surg. 2010;18:597–607. 2. Court-Brown CM, Caesar B.  Epidemiology of adult fractures: a review. Injury. 2006;37:691–7. 3. Smith JRA, Halliday R, Aquilina AL, Morrison RJM, Yip GCK, McArthur J, Hull P, Gray A, Kelly MB, OTS COTS.  Distal femoral fractures: the need to review the standard of care. Injury. 2015;46:1084–8.

4. Gangavalli AK, Nwachuku CO. Management of distal femur fractures in adults: an overview of options. Orthop Clin North Am. 2016;47:85–96. 5. Cass J, Sems SA. Operative versus nonoperative management of distal femur fracture in myelopathic, nonambulatory patients. Orthopedics. 2008;31:1091. 6. Handolin L, Pajarinen J, Lindahl J, Hirvensalo E. Retrograde intramedullary nailing in distal femoral fractures—results in a series of 46 consecutive operations. Injury. 2004;35:517–22. 7. Ebraheim NA, Liu J, Hashmi SZ, Sochacki KR, Moral MZ, Hirschfeld AG.  High complication rate

76 in locking plate fixation of lower periprosthetic distal femur fractures in patients with total knee arthroplasties. J Arthroplast. 2012;27:809–13. 8. Hoffmann MF, Jones CB, Sietsema DL, Koenig SJ, Tornetta P.  Outcome of periprosthetic distal femoral fractures following knee arthroplasty. Injury. 2012;43:1084–9. 9. Ruchholtz S, Tomás J, Gebhard F, Larsen MS.  Periprosthetic fractures around the knee-­ the best way of treatment. Eur Orthop Traumatol. 2013;4:93–102. 10. Langford J, Burgess A. Nailing of proximal and distal fractures of the femur: limitations and techniques. J Orthop Trauma. 2009;23:S22–5. 11. Zlowodzki M, Williamson S, Zardiackas LD, Kregor PJ.  Biomechanical evaluation of the less invasive stabilization system and the 95-degree angled blade plate for the internal fixation of distal femur fractures in human cadaveric bones with high bone mineral density. J Trauma: Injury, Infection, and Critical Care. 2006;60:836–40. 12. Zlowodzki M, Williamson S, Cole PA, Zardiackas LD, Kregor PJ. Biomechanical evaluation of the less invasive stabilization system, angled blade plate, and retrograde intramedullary nail for the internal fixation of distal femur fractures. J Orthop Trauma. 2004;18:494–502. 13. Poole WEC, Wilson DGG, Guthrie HC, Bellringer SF, Freeman R, Guryel E, Nicol SG. “Modern” distal femoral locking plates allow safe, early weight-­ bearing with a high rate of union and low rate of failure: five-year experience from a United Kingdom major trauma Centre. Bone Joint J. 2017;99-B:951–7. 14. Su ET, DeWal H, Di Cesare PE. Periprosthetic femoral fractures above total knee replacements. J Am Acad Orthop Surg. 2004;12:12–20. 15. Maniar RN, Umlas ME, Rodriguez JA, Ranawat CS.  Supracondylar femoral fracture above a PFC posterior cruciate-substituting total knee arthroplasty treated with supracondylar nailing. A unique technical problem. J Arthroplasty. 1996;11:637–9. 16. Hanks GA, Mathews HH, Routson GW, Loughran TP.  Supracondylar fracture of the femur following total knee arthroplasty. J Arthroplasty. 1989;4:289–92. 17. Rorabeck CH, Taylor JW. Classification of periprosthetic fractures complicating total knee arthroplasty. Orthop Clin North Am. 1999;30:209–14. 18. Ehlinger M, Adam P, Abane L, Arlettaz Y, Bonnomet F.  Minimally-invasive internal fixation of extra-­ articular distal femur fractures using a locking plate:

J. A. Canseco et al. tricks of the trade. Orthop Traumatol Surg Res. 2011;97:201–5. 19. Collinge CA, Gardner MJ, Crist BD.  Pitfalls in the application of distal femur plates for fractures. J Orthop Trauma. 2011;25:695–706. 20. Hierholzer C, Rüden C, Pötzel T, Woltmann A, Bühren V. Outcome analysis of retrograde nailing and less invasive stabilization system in distal femoral fractures: a retrospective analysis. Indian J Orthop. 2011;45:243–15. 21. Beltran MJ, Gary JL, Collinge CA.  Management of distal femur fractures with modern plates and nails: state of the art. J Orthop Trauma. 2015;29:165–72. 22. Miller MD, Thompson SR, Hart J. Miller’s review of orthopaedics. Philadelphia: Elsevier Health Sciences; 2015. 23. Ehlinger M, Ducrot G, Adam P, Bonnomet F. Distal femur fractures. Surgical techniques and a review of the literature. Orthop Traumatol Surg Res. 2013;99:353–60. 24. Collinge CA, Sanders RW.  Percutaneous plating in the lower extremity. J Am Acad Orthop Surg. 2000;8:211–6. 25. Hoppenfeld S, de Boer P, Buckley R.  Surgical exposures in Orthopaedics: the anatomic approach. Philadelphia: Lippincott Williams & Wilkins; 2016. 26. Smith TO, Hedges C, MacNair R, Schankat K. Early rehabilitation following less invasive surgical stabilisation plate fixation for distal femoral fractures. Physiotherapy. 2009;95:61–75. 27. Smith WR, Stoneback JW, Morgan SJ, Stahel PF. Is immediate weight bearing safe for periprosthetic distal femur fractures treated by locked plating? A feasibility study in 52 consecutive patients. Patient Saf Surg. 2016;10:26. 28. Salter RB, Simmonds DF, Malcolm BW, et  al. The biological effect of continuous passive motion on the healing of full-thickness defects in articular cartilage. J Bone Joint Surg Am. 1980;62(8):1232–51. 29. Smith TO, Hedges C, MacNair R, Schankat K, Wimhurst JA. The clinical and radiological outcomes of the LISS plate for distal femoral fractures: a systematic review. Injury. 2009;40:1049–63. 30. Henderson CE, Lujan TJ, Kuhl LL, Bottlang M, Fitzpatrick DC, Marsh JL. 2010 mid-America Orthopaedic association physician in training award: healing complications are common after locked plating for distal femur fractures. Clin Orthop Relat Res. 2011;469:1757–65.

8

Epidemiology and Classification of Proximal Tibia Fractures Arindam Banerjee

8.1

Introduction

The understanding of proximal tibial fractures along with optimum treatment has changed considerably over the last few decades. This is due to: 1. A better understanding of the changing epidemiology of the fracture. This variation is due to changing lifestyles due to urbanisation and industrialisation, population ageing as well as regional variations such as roads logistics and transportation. 2. A better understanding of the 3D fracture patterns with the advent and usage of modern CT scan machines which have greatly altered our awareness of fracture patterns which again has led to change in fracture classification. 3. The understanding that soft tissue plays a crucial role in treatment of these fractures. The concept of internal degloving injury which has been appreciated by our plastic surgical colleagues long before we did and who are frequently asked to help us achieve stable soft tissue cover [1].

A. Banerjee (*) NH Narayana Superspeciality and Multispeciality Hospitals, Howrah, West Bengal, India Institute of Neurosciences, Kolkata, West Bengal, India

This chapter deals with all the above issues. It also deals with open fractures of proximal tibial fractures which are an important and difficult subgroup of this injury.

8.2

Epidemiology of Proximal Tibia Fractures

Worldwide, the epidemiology of fractures is changing. Some of the leading causes are enumerated below though the list is not exhaustive: • The population of the world is ageing. This leads to more fractures (as ageing bone is more vulnerable to a smaller quantum of trauma) as well as a changing fracture geometry [2]. • People are less active than they were decades ago. The labour-saving devices and increase in usage of computers and social media have made us more sedentary individuals more prone to osteoporosis and consequently more fractures [3]. • Increasing body mass due to rising BMI has made us more injury prone as the energy spent at the point of impact is dependent on the body mass of the individual (kinetic energy =1/2 mv2). • The increase in the speed of transport worldwide has contributed as the energy at the point of impact (kinetic energy) the square of the

© Springer Nature Switzerland AG 2021 M. Hanschen et al. (eds.), Knee Fractures, Strategies in Fracture Treatments, https://doi.org/10.1007/978-3-030-81776-3_8

77

A. Banerjee

78

velocity of the individual. This is more important in rapidly industrialising and urbanising nations who have lax traffic management. In our experience in India, motorbike accidents are the frequent culprits [4]. • Dietary changes and less exposure to sunlight is another important factor. Individuals seem to have lower levels of vitamin D than previously recorded [5]. The jury is still out on whether this needs to be treated on a routine basis. With these general changes in mind, we need to focus on the epidemiology of proximal tibial fractures. A review of the epidemiology of proximal and distal tibial fractures in Edinburgh has shown a slight increase in proximal tibial fractures from 13.3/100000/year in 2000 to 15.6/100000/year in 2007/2008. The average age of patients presenting with proximal tibial fractures rose from 48.9 years in 2000 to 56.0 years in 2007/2008. The increase in average age is perhaps a reflection that in a section of the increasingly affluent population, older patients having more sporting and travel activity than in previous generations [6]. This data corroborated with a Danish study [7] which reviewed all patients within a geographic area of North Denmark from 2005 to 2010 and found a prevalence rate of 10.3/100000 population with a mean age of 52.6. Other interesting factors which were highlighted in this study were the following: • Commonest age range for this fracture in men and women 40–60  years. Mean age was for 46.8 (M) and 57.7 (F). • More women had this fracture if all age groups considered but there were more men in the age group >50 years. • Commonest fracture types – AO 41-B3 (35%) and 41-C3 (17%) as per the AO/OTA classification. • Commonest cause of injury in men was the motorcycle and other motorised injuries as well as fall from heights. In women, the main causes were bicycling, indoor walking as well as fall from heights. The advantage of studies from Scandinavia is that they are able to include their entire populations within their studies as their resources are

higher, relative to their population. They also have a high degree of universal health care in the public domain. High literacy also helps. Albuquerque et al. from Brazil in 2013, however, found a strong male preponderance (70%) which could be due to different set of population dynamics, different types of injuries or the exclusion of fractures treated conservatively in their series [8].

8.3

Patterns and Classification of Proximal Tibia Fractures

Fractures generally have been classified in many ways. But the importance of any classification lies with only one major factor – it should have bearing on the management of that fracture. In this chapter, we will discuss three important classifications: • Schatzker • AO • The three column classification

8.3.1 Schatzker Classification [Ref. 9 and Fig. 8.1] The earliest attempt at tibial plateau fracture classification was based on the observation of common themes and three fracture types were described: 1 . Split of a condyle 2. Subchondral depression 3. Comminuted bicondylar involvement Schatzker et  al. presented their classification system in the 1970s, which was created based on findings from AP radiographs. The Schatzker group recognised six groups of tibial plateau fractures based on fracture pattern, which helped to decide on operative versus nonoperative treatment.

8.3.2 AO/OTA Classification [Ref. 10 and Fig. 8.2] The AO/OTA system is part of a larger system of classification of bone fractures throughout the body, meant to categorise the fracture by localisation and severity and to predict treatment and prognosis.

8  Epidemiology and Classification of Proximal Tibia Fractures

Type I Split

Type II Split-depression

Type III Central depression

Type IV Split fracture, medial plateau

79

Type V Bicondylar fracture

Type VI Dissociation of metaphysis and diaphysis

Fig. 8.1  Graphic representation of the Schatzker classification

Fig. 8.2  Diagrammatic representation of the AO/OTA classification

The importance of the AO/OTA classification is twofold: • All fractures of the human body are classified under the same system. • Since it documents fractures in great detail, it is possible to assign a grade to every fracture. This is excellent for documentation and future comparison of outcomes of the same fracture treated by different techniques or from different medical centres.

8.3.3 The Three-Column Classification [Ref. 11, 12 and Fig. 8.3] With the widespread use of 3D CT in preoperative surgical planning a three-column the-

ory of classifications has evolved. These authors claim that fractures of the posterior column are not fully appreciated in plain x-rays. Elevating and fixing the posterior column is important to restore the joint line and minimise secondary osteoarthrosis of the joint. It gives us an idea on whether primary bone grafting is required for ORIF.  Preoperative C-arm imaging is required to check whether the quantity of bone graft used for the procedure is sufficient. Luo et  al. have introduced the three-column classification of tibial plateau fractures. This classification is based on three pillars and can be used as a supplement to the conventional Schatzker classification, since especially posterior column fractures are not well depicted in the conventional classifications. Subsequently, the three-column classification helps the surgeon to

A. Banerjee

80 Fig. 8.3 Diagrammatic representation of the three-column classification

better understand the fracture type and plan the operative procedure preoperatively.

8.4

Concomitant Injuries and Classification of Open Fractures of the Proximal Tibia

8.4.1 Concomitant Injuries The proximal tibial fracture often has associated injuries. These injuries fall under the following categories: Fractures of other bones. The following bones are often involved either alone or in a combination: 1 . Fractures of the distal femur 2. Fractures of the patella 3. Fractures of the fibula (including lower fibula) Injuries of the knee joint (separate injuries or in combination): 1. Meniscal injuries 2. Ligamentous injuries Neurovascular injuries: 1. Arterial injuries are very common especially with the subtype.

2. Significant nerve injuries causing foot drop are not common except in sharp injuries and military trauma.

8.4.2 Classification of Open Fractures of the Proximal Tibia Open fractures are a different subgroup of fractures based on soft tissue injuries. There is no direct connection with fractures of the proximal tibia and open fractures. However since the proximal tibia is a region of the body which is frequently exposed to external injuries such as motorbikes and car bumpers, it is particularly vulnerable during road traffic accidents. Since the proximal tibia has very little soft tissue cover and is subcutaneous in its medial aspect, it is easily stripped by the fracture causing force leading to an open injury. The importance of open fractures lies in the susceptibility of the fracture and its surrounding tissue to infection. Since this is a fairly common injury, it is necessary to classify this subgroup of fractures separately. Also this is a generic classification which is applicable to all regions of the body. We will discuss three important classifications: • Gustilo-Anderson Table 8.1]

classification

[13

and

8  Epidemiology and Classification of Proximal Tibia Fractures Table 8.1  Gustilo-Anderson open fracture classification Gustilo grade Definition I Open fracture, clean wound, wound 1 cm but 10 cm [4]), damage or loss or an open segmental fracture. This type also includes open fractures caused by farm injuries, fractures requiring vascular repair or fractures that have been open for 8 h. prior to treatment IIIA Type III fracture with adequate periosteal coverage of the fracture bone despite the extensive soft tissue laceration or damage IIIB Type III fracture with extensive soft tissue loss and periosteal stripping and bone damage. Usually associated with massive contamination. Will often need further soft tissue coverage procedure (i.e. free or rotational flap) IIIC Type III fracture associated with an arterial injury requiring repair, irrespective of degree of soft tissue injury

• The Ganga hospital classification [14, 15] • The AO classification of open injuries [16] The Gustilo-Anderson score (Table 8.1) is the most widely known and frequently used. However it has several drawbacks. It is based on the size of the wound and needs reclassification after every debridement. But more important, the IIIB fracture is a complex injury and needs detailed subgrouping. This deficiency has been addressed in the Ganga Hospital score (Table  8.2) by detailed focusing on the type of tissue involvement. This tissue could be skin and subcutaneous tissue, functional motor units such as muscle/tendon/ nerves or skeletal tissue such as bones or nerves. The Ganga Hospital score also addresses the role of comorbidities on tissue healing something orthopaedic surgeons are becoming increasingly aware of. This score allots points from one to five according to the severity of injury to each of the three components of the limb, namely:

81

Table 8.2  Ganga Hospital score Covering structures: Skin and fascia Score Wounds without skin loss  Not over the fracture 1  Exposing the fracture 2 Wounds with skin loss  Not over the fracture 3  Over the fracture 4 Circumferential wound with skin loss 5 Skeletal structures: Bone and joints  Transverse/oblique fracture/butterfly 1 fragment  50% circumference 2  Comminution/segmental fractures without 3 bone loss  Bone loss  65 years 4. Drug dependent diabetes mellitus/cardio respiratory diseases leading to increased anesthetic risk 5. Poly trauma involving chest or abdomen with ISS>25/Fat embolism 6. Hypotension with systolic blood pressure 5 neutrophils per high-powered field (x400 magnification) on histology

© Springer Nature Switzerland AG 2021 M. Hanschen et al. (eds.), Knee Fractures, Strategies in Fracture Treatments, https://doi.org/10.1007/978-3-030-81776-3_18

Suggestive criteria Clinical signs of infection (Local and systemic) Radiological and/or nuclear imaging signs New onset joint effusion Elevated serum inflammatory makers

Persistent wound drainage Pathogenic organism identified by culture from a single deep tissue/implant specimen 159

J. Ferguson et al.

160

18.1.2 Risk Factors and Epidemiology of Infected Nonunion There are several factors that predispose to infected nonunion, as summarised in Table 18.2. Host factors include comorbidities that impair the immune response. Local factors relate to the severity of the original injury, the integrity of the soft tissues, the quality of the bone and the organism virulence. Finally there are surgical factors, which have a detrimental effect if poor operative decisions are made. Fracture-related infections are rare in non-­ operatively treated close fractures. The rate of infection in surgically fixed closed fractures is thought to be around 1–2% [8]. The infection rates in open fractures are related to the severity of the soft-tissue injury [9], with infection rates of 0–2% in Gustilo-Anderson type I fractures, 2–10% for type II and up to 10–50% for type III injuries [10]. Open tibial fractures are particularly susceptible to infection, with infection rates twice as high as similar grade injuries in other bones [11]. Other risk factors include a history of compartment syndrome, pathological fractures or a history of previous local radiotherapy. Surgery on previously aseptic nonunions carries an infection risk twice that of acute fracture fixation [12, 13]. Prolonged use of vacuum-assisted closure devices and delays in definitive soft-tissue cover for open fracture wounds are associated with a higher rate of deep infection [14, 15]. The demographics of patients undergoing internal fixation of fractures in the developed

world has changed. An aging population with associated comorbidites, such as immunocompromise and osteoporosis, has led to an increased risk of developing infected nonunion [16, 17].

18.1.3 Patient Factors The higher the number of associated comorbidities a patient has, the higher the risk of infection and poorer outcome following treatment. The risk of developing infection following open fracture was found to be almost three times greater if one or two comorbidities were present and up to six times higher when there were three or more comorbidities [18]. In the LEAP study (Lower Extremity Assessment Project), smoking was found to more than double the risk of developing infection and prolong union time and was associated with a 3.7 times increase in the risk of developing osteomyelitis at the site of a limb-threatening open tibial fracture [19]. Clinical presentations of infection may be atypical in the immunocompromised host when more indolent organisms can cause infection without the florid signs normally expected, resulting in delay to diagnosis.

18.1.4 Pathophysiology of Fracture-­ Related Infection During a fracture there is damage to the surrounding soft tissues, with periosteal stripping

Table 18.2  Risk factors for the development of infected nonunion Host factors Nutritional deficiency Smoking Drug abuse Steroid use Vascular insufficiency Immunocompromised Metabolic disorders

Local factors Open fracture Soft-tissue deficiency Poor bone stock • High-energy fracture patterns  – Comminution  – Bone defects Osteoporosis Organism • Virulence • Antibiotic resistance

Table adapted from Lammens et al. [7]

Surgical errors Inadequate stabilisation Inadequate debridement Excessive soft-tissue stripping • Poor approach selection • Incorrect timing of surgery • Excessive osteosynthesis Delay to definitive soft-tissue coverage Malalignment

18  Infected Nonunions Around the Knee

161

Fig. 18.1 Distal femoral fracture treated with ORIF. Note the comminuted fracture pattern and use of medial and lateral plating which has resulted in extensive soft-tissue striping and a large femoral sequestrum

occurring in proportion to the energy transferred to the limb. Soft-tissue stripping can be further exacerbated through surgical approaches to stabilise the fracture (see Fig. 18.1). During fracture healing, small areas of dead bone caused by this stripping are gradually replaced by creeping substitution. However, if infection does develop, these areas of bone can act as a nidus for infection. Planktonic organisms may adhere to dead bone, implants or poorly vascularised soft tissue using specific factors called adhesins, and during an accumulative phase they start to adhere to one another, forming a biofilm. This is a complex self-produced polymer matrix consisting of polysaccharides, proteins and DNA [20]. This early biofilm can quickly mature and become more resistant to elimination by severely limit-

ing antimicrobial action and the host immune response [21]. The organisms are able to signal to one another through a process called quorum sensing that can modify organism behaviour to support the maturation of the biofilm. The organisms contained within the biofilm enter a slow growing or dormant state, rendering them up to 1000 times more resistant to the immune system or antimicrobial agents compared to normal planktonic organisms [22, 23]. Established biofilms are then able to release planktonic organisms [21] that can disseminate and incite local inflammation. This induces leucocytes to release cytokines such as tumour necrosis factor alpha (TNF-α), ­interleukin 1 and interleukin 6, which cause upregulation of osteoclastic activity through the receptor activator of nuclear factor-

J. Ferguson et al.

162

kB (RANK) system, resulting in osteolysis and implant loosening [24]. The presence of a foreign body, such as an implant, significantly increases infection susceptibility. This has been demonstrated in both human and animal models where the presence of a subcutaneous implant resulted in more than a 100,000-fold reduction in the number of Staphylococcus aureus organisms required to result in abscess formation [25, 26]. Furthermore, there is some evidence that the presence of metal implants may also inhibit granulocyte and plasma cell function as well as T-cell activation [27]. This inoculation of microorganisms can occur at the time of the injury (as in an open fracture), intraoperatively during surgical fixation or post-

operatively if there are problems with wound healing or delays to definitive closure [8].

18.1.5 Duration of Infection Fracture-related infection has been classified on the basis of the time from fixation to symptom onset into early (less than 2 weeks duration), delayed (3rd–10th week duration) and late (greater than 10 weeks duration) (see Table 18.3) [28]. In reality these timeframes should not be seen as absolutes, but they do highlight that the evolution of infection exists on a spectrum, such that the longer the process has been allowed to continue, the greater the risk of bone lysis, sequestrum formation and instability developing.

Table 18.3  Variations in presentation and treatment options for fracture-related infection depending on time of symptom onset after initial surgery Time after fracture fixation Early 10 weeks

(a) Chronic • Pain • Instability • Sinus formation • Wound breakdown (b) Haematogenous (rare) • Acute symptoms as above

Polymicrobial and resistant organisms more common due to delayed or poor previous treatment • Staphylococcus aureus • Escherichia coli

Treatment options Early intervention required •S  urgical debridement and implant retention • Ensure good soft-tissue cover • Antibiotics guided by intraoperative sampling If implant stable: • Debridement • Implant retention possible • Soft-tissue reconstruction Culture-guided antibiotic treatment If implant lose: • Consider exchange fixation or removal and external fixation • Consider local antibiotics • Soft-tissue reconstruction • Culture-guided antibiotic treatment If nonunion with infection clinically expected: • Debridement with implant exchange/ removal • Reconstruction • Antibiotics If nonunion lacking signs of infection: • Intraoperative sterile site sampling • Exchange implant • Antibiotics until infection ruled out by samples If united with infection clinically expected: • Debridement with implant removal • Reconstruction • Antibiotics

18  Infected Nonunions Around the Knee

The impact a pathogen has on the local biological environment of fracture healing is a function of the organism’s virulence, the duration of time the infection has been present, and the integrity of the host immune system. More virulent organisms such as Staphylococcus aureus are more likely to present at an earlier stage and incite a more florid inflammatory response that can quickly lead to bone lysis, soft-tissue damage, implant loosening, and suppression of fracture healing. In contrast, more indolent organisms such as Staphylococcus epidermidis may only precipitate a low-grade inflammatory response, resulting in less obvious signs of infection. In this situation diagnosis is commonly delayed because infection symptoms are often more non-specific, allowing the inflammation to persist for much longer before being treated. This allows biofilm to become established in the operative field and on the implant that can result in implant loosening or failure of fracture healing. Any case presenting with a painful non-union and radiographic appearances of progressive bone lysis should be considered infected until proven otherwise. The indicators of the severity of infected nonunion are the extent of bone necrosis and/or sequestra, the size of any bone defects and the virulence of the causative organism [7].

18.2 Preoperative Planning 18.2.1 Diagnosis Infected nonunion can present in one of two ways. Firstly, an early infection can be missed or receive suboptimal treatment with antibiotics alone, allowing it to evolve and become an established infected nonunion. Secondly, infection can be caused by a relatively low-virulence organism, and in this situation there may be an absence of typical symptoms such as sinus formation or systemic upset. Most commonly the patient may complain of non-specific pain or local swelling. Due to the more indolent nature of these types of organisms, blood tests are often unhelpful as inflammatory markers may be falsely reassuring. Often the alarm is only raised because the fracture is failing to unite or the implants are showing gradual signs of loosening or fatigue failure.

163

With some implants, such as a retrograde femoral nail, there is a risk of a septic arthritis developing if the infection is able to track down the implant and into the joint. In these situations emergent treatment is required with diagnostic joint aspiration and prompt knee washout.

18.2.2 Clinical Presentation The diagnosis of an infected nonunion may be obvious. Wound breakdown or on-going ­drainage, combined with an absence of fracture consolidation, confirms infected nonunion. However, bone may develop a hypertrophic pattern of healing with a relatively stiff nonunion in the presence of infection. In some cases, the diagnosis may be difficult. If a fracture around the knee is not healing, infection should be considered likely until it is excluded. Delay in diagnosis may also result from the inappropriate use of antibiotics that can mask more overt symptoms [29].

18.2.3 Laboratory Tests Following fracture and surgical fixation, the white cell count, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) may well be elevated. In a normal situation, the CRP should normalise within 1–2 weeks. If these blood markers remain high beyond this timeframe, then infection should be considered, particularly in the presence of the clinical signs discussed above. However, none of these tests are either sensitive or specific for infection, particularly when the organism is more indolent. Even in patients with chronically draining sinuses, the blood markers may remain normal [8]. Blood cultures are usually unhelpful because of their poor sensitivity. However, if the individual is unwell with a fever, blood cultures should be taken before antibiotic therapy is instigated, as this may be the only opportunity to gain a microbiological culture sample that yields the causative organism [30].

J. Ferguson et al.

164

18.2.4 Imaging 18.2.4.1 Plain Radiographs Serial plain radiography can define the progression of union or the gradual failure of fixation. Signs suggestive of loosening include progressive lucency around fixation or screw breakage. Periosteal new bone formation is an encouraging indicator that the underlying bone is well vascularised. If this is absent after several months, it indicates the underlying bone is likely to be dead.

a

b

c

e

g

After injury, disuse of the injured limb will cause osteopenia. In contrast, sequestered bone is unable to undergo remodelling and will therefore remain at the pre-injury density, appearing relatively “sclerotic” compared to the surrounding healthy bone. Dead fracture fragments retain a well-demarcated sharp margin without becoming rounded-off or fuzzy. Although these signs are not specific, rapidly progressive lucency on serial imaging is highly suggestive of infection (see Fig. 18.2c, d).

d

f

h

Fig. 18.2  Serial radiographs of a segmental femoral fracture in a 63-year-old lady treated with an intramedullary nail and lateral plate (a). At 4 months, there was a failure of bone healing and minimal remodelling of the fracture, suggesting devascularisation (b). Despite removal of the plate and revision nailing at 4 months (c), there was evidence of progressive bone lysis, suggesting infection at 6 months when they were referred (d). There was sinus formation within the lateral scar (e). At surgery, the nail was

i

j

removed, the canal was reamed, the locking bolts holes were over-drilled and the canal was washed and filled with antibiotic-eluting calcium sulphate pellets (f). Next a 4 cm segmental excision was undertaken to healthy bleeding bone (g), and an Ilizarov frame was used to acutely compress the nonunion site (h). The initial postoperative radiograph showing the frame with corticotomy below the third half pin to allow limb length equalisation (i). Clinical photograph of frame three weeks following application (j)

18  Infected Nonunions Around the Knee

18.2.4.2 Ultrasonography This investigation is useful in identifying fluid collections around implants or joint effusions that might suggest infection. Ultrasound can also guide fluid aspiration for microbiological culture. However, the presence of an effusion does not necessarily indicate infection in this context as a reactive sterile knee effusion can occur adjacent to an implant infection or nonunion. 18.2.4.3 Computer Tomography CT scanning is helpful in determining if implant loosening is present and whether the fracture has united. It can also help in surgical planning by defining the extent of osteonecrosis and is particularly helpful in identifying small areas of sequestered bone that may not be easily seen on plain film imaging. CT imaging can also help in identifying viable cortical bone, which can be seen to have new periosteal bone forming upon it. CT is poor at visualising the soft tissues and the path of sinuses. Image quality can be degraded by the presence of metal implants, with titanium causing less distortion than stainless steel [12]. Metal artefact reduction sequences (MARS) can limit this to a degree, as can trying to align the axis of the implant with the CT gantry and using narrow collimation [31]. 18.2.4.4 Magnetic Resonance Imaging MRI scanning is the investigation of choice for bone infection when there is no metalwork present. It is able to visualise the extent of osteomyelitis, demonstrate subperiosteal and soft-tissue collections, cloaca, medullary abscesses and sinus tracts. MRI tends to overplay the area of infection involvement as the oedema surrounding infection also shows up as high signal intensity. Furthermore, it is unable to differentiate between living and dead cortical bone, although sequestra are often clearly seen if they have detached from the surrounding bone. Unfortunately MRI is not very good at differentiating between septic and aseptic nonunion, and its diagnostic utility is greatly diminished in the presence of metalwork, due to artefact.

165

18.2.4.5 Nuclear Imaging Whilst a variety of different nuclear imaging modalities are available, in general they add little to the diagnosis of infected nonunion. The bone gallium-67 or technetium-99m scintigraphy lacks sensitivity, because they are prone to false-­ positive results caused by trauma, surgery, on-­ going fracture healing and degeneration. The indium-111-labelled leukocyte scan has a superior accuracy of 90% [32], but it is time-­ consuming and only produces two-dimensional imaging. These types of radionuclide scans may have more of a role in excluding infection in a patient where the index for suspicion is relatively low. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) are nuclear medicine imaging techniques that use a labelled ligand to give a three-­ dimensional image of metabolic activity. They are often combined with CT to provide anatomic information that helps localise areas of high metabolic activity, such as infected nonunion. SPECT uses a gamma-emitting radioisotope tracer (such as technicium-99, iodine-123 or iodine-131), whereas 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) uses a radiolabeled glucose molecule that emits positrons. Its theoretical advantages over a radiolabeled leucocyte scan are that it is quicker to administer (requiring a single scan as opposed to two different scans on 2 different days) and involves a lower radiation exposure. Both SPECT and FDG-PET have a high diagnostic accuracy, but the three-dimensional resolution of FDG-­ PET is superior, giving clear anatomical information that can help preoperative surgical planning by defining the anatomical distribution of the infected or dead bone [33].

18.2.5 Microbiological and Histological Diagnosis Sampling for microbiological and histological analysis is an important component of successful infection treatment. Sterile site microbiological

166

culture is the definitive test for establishing the diagnosis of infection (see treatment section below). Surface swabs of the wound or draining sinuses should be avoided because their results are misleading due to skin commensal contamination. Radiologically guided samples may be taken, but the accuracy of intraoperative sampling is higher [34]. Treatment can be compromised by providing the microbiologist with poor samples, which can result in an antibiotic lottery and less reproducible outcomes. If possible, all antibiotics should be stopped at least two weeks before sampling is undertaken to optimise the intraoperative sample culture yields.

18.2.6 Classification of Infected Nonunion It is useful to subdivide infected nonunion as it can be helpful in planning treatment. Weber and Čech proposed a classification system for all nonunions based on the viability of the bone ends [35]. Types A, B and C are said to be viable, because there is vascular bone present on both sides of the nonunion. Type D has non-vascular bone on one or both sides of the nonunion but with no segmental defect, type E as a separate dead piece of sequestered bone, and types F and G are associated with bone defects. Areas of non-­ viable bone are much more commonly encountered in infected nonunion. This classification highlights the importance of identifying areas of dead bone, which must be removed to eradicate the infection and allow bone union (see Fig. 18.3f, g).

18.3 Infection and Reconstruction Management 18.3.1 General Principles of Management The principal aims of treating infected nonunion are [17]: 1. Achieving fracture union

J. Ferguson et al.

2. Infection eradication or infection suppression until fracture union is achieved 3. Restoration of a competent soft-tissue envelope 4. Prevention of residual chronic osteomyelitis after bone healing 5. Return of function In contrast to acute fracture-related infection, there is an increasing recognition that treatment of infected nonunion is best delivered in a multidisciplinary environment, involving the skills of orthopaedic surgeons, infectious disease physicians, radiologists with a special interest in musculoskeletal conditions and plastic surgeons with expertise in managing bone infection [36]. Successful treatment of infected nonunion around the knee depends on several important principles [37]: • Preoperative –– Optimisation of reversible medical comorbidities affecting the individual –– Diagnostic tests to look for underlying medical problems and to assess the vascularity of the limb –– Discussion of treatment options and ensuring realistic outcomes are understood • Operative –– Adequate microbiological and histological sampling –– Thorough debridement with removal of avascular dead bone –– Osseous stabilisation ensuring mechanical axis is corrected. This might need to be achieved with either implant retention, implant exchange or external fixation –– Dead space management –– Delivery of antimicrobial therapy using local and systemic antibiotics –– Soft-tissue coverage • Postoperative –– On-going culture-specific antimicrobial therapy –– Early functional rehabilitation of the knee joint –– Close follow-up to monitor for signs of infection recurrence or other complications –– Staged secondary reconstruction for malunion, joint stiffness or on-going nonunion

18  Infected Nonunions Around the Knee

18.3.2 Particular Challenges Faced in Infected Nonunion Around the Knee Generally epiphyseal and metaphyseal fractures have a better healing potential compared to a

b

e

f

Fig. 18.3  A 28-year-old sustained a closed intra-articular distal femoral fracture that was treated with a lateral plate (a). A lateral sinus developed 4 months later, and his plate was removed followed by serial debridement and a VAC dressing (b, c). As a consequence of the lack of osseous stability following plate removal, the knee drifted into varus (d, e), and there was associated chondral damage noted on the radiographs when he was referred (f, g). There is new periosteal bone formation noted on all bone fragments suggest-

167

diaphyseal fractures due a greater surface area for healing and better local blood supply. Sequestra are also less common in these regions compared to the more susceptible thicker diaphyseal cortex. Nevertheless, there are some issues that can complicate injuries around the knee. c

d

g

ing that the nonunion remains viable (f, g). Initial post operative imaging following stabilisation with Ilizarov frame after excision of non-viable nonunion. Note corticotomy in femoral diaphysis to restore leg length discrepency (h). In cases with an intra-articular non union such as this, the use of an Ilizarov that initially spans across the knee to the tibia should be considered. Frame distraction to correct leg length discrepency and mechanical axis (i). AP and lateral images following frame removal after 5.5 months (j, k)

J. Ferguson et al.

168

h

i

j

k

Fig. 18.3 (continued)

18  Infected Nonunions Around the Knee

1. There is a risk of damage to the chondral surfaces, which may occur due to the initial injury, as a result of surgery or owing to the effects of an associated septic arthritis. Great care must be taken to try and preserve the joint surface, although in some instances this is not possible and subsequent knee arthroplasty may be necessary. 2. Relatively small deformities around the knee can result in marked axis malalignment which can cause overload of the joint and subsequent arthrosis, as well as accelerate fracture fixation failure. Intra-articular nonunions are best managed with absolute stability and early range of movement. This can be challenging to achieve, particularly if removal of internal fixation may destabilise the joint surface further. Attaining adequate stability can be problematic with external fixation alone. 3. The knee is prone to developing stiffness with an infected nonunion due to the summative effects of the initial tissue injury, subsequent surgery, periods of immobilisation, continuing implant instability and persistent infection. Involvement of specialist physiotherapists at an early stage is crucial to avoid a compromised outcome.

18.3.3 Timing of Surgery in Established Infected Nonunion Once an infected nonunion is established, there is usually no urgent need to undertake definitive surgical treatment. Time is better invested in optimising the patient before surgery. Every effort should be made to investigate and treat potential issues that will impede healing. Encouraging smoking cessation, improving nutritional status, controlling diabetes and improving the limb vascularity will increase the chance of a successful outcome. All antibiotics should be stopped at least two weeks before surgery to optimise microbiological culture yields. In rare situations a patient may present generally unwell with severe sepsis, which may manifest as tachycardia, pyrexia and hypotension. In

169

these settings it is important to stabilise the condition of the patient rather than consider definitive management of the nonunion. This situation is usually the result of an abscess or septic ­arthritis. The treatment priority is therefore to resuscitate the patient, arrange urgent imaging and decompress these collections and drain abscesses. Blood cultures should be obtained before intravenous antibiotics are commenced, and surgical microbiological samples should also be taken. Wound closure is not required acutely, but can be performed with the definitive surgery once the patient is stable.

18.3.4 Principles of Surgical Management of Infected Nonunion 18.3.4.1 Microbiological Sampling It is important to establish the causative organism(s) to allow targeted antimicrobial therapy. The key to improving the accuracy of microbiological sampling lies in taking multiple uncontaminated, representative samples. If too few samples are taken, the sensitivity of these cultures drops. If too many are taken, the specificity falls with an increased false-positive result, due to contamination. In our centre, five separate microbiological samples are taken which represents the best compromise in test accuracy and the available resources of the microbiological laboratories [34]. Fracture-related infection is confirmed if at least two separate deep tissue samples culture phenotypically identical organisms or if microorganisms are confirmed by histopathological examination. A pathogenic organism identified by a single deep tissue/ implant specimen is only suggestive for a fracture-­related infection, and further investigation is required to confirm the diagnosis [6]. Meticulous care is taken to avoid the potential for contaminated samples that can give misleading results. Samples are taken early in the procedure with the initial part of the operation solely dedicated to collecting representative samples. Each sample should be taken with a separate set of instruments, ensuring that their tips are not

170

handled by the scrub nurse and do not come into contact with the patient’s skin. To limit contamination of these samples, the surgeon should not place his finger in the wound and avoid using suction until after sampling is complete. Until then a clean gauze swab may be used to dry the operative field so that appropriate sampling areas can be identified without compromising the sampling region. Any sinus tract present should be excised, but microbiological analysis of this specimen is not helpful due to its contamination from the skin surface. Deep samples of any pus, abnormal granulation tissue and dead tissue are sent. The membrane around or under a plate is particularly helpful to culture. It is useful to send one or two histological specimens, which may corroborate the diagnosis of infection if no organisms are cultured. To maximise culture yields, samples for bacteriology should be sent straight to the laboratory as soon as sampling is complete, and the laboratory should be warned if any special culture techniques are required or atypical organisms are suspected [38]. Empiric antibiotics can then be given after sampling has been completed or within 10 min of deflating the tourniquet, if used [34].

18.3.4.2 Debridement The success of infection eradication mainly relies on the quality of debridement performed. Therefore debridement should not be limited by concerns of creating bone or soft-tissue defects [39]. To ensure removal of biofilm, the surface of the cortical bone under any plates should be removed with a chisel until bleeding bone is encountered. Any screw holes should be over-­drilled. If an intramedullary device has been used, this should be removed and the canal reamed to ensure the endosteal biofilm has been removed. Care should be taken to ensure the locking bolt holes are also over-drilled. Windowing involucrum may be required to reach intramedullary sequestra. Preoperative imaging should be scrutinised to identify sequestra or intracortical abscesses to aid planning the best approach, which should avoid unnecessary removal of healthy bone.

J. Ferguson et al.

The best way of assessing the vitality of the bone is to look at the bleeding pattern after exposure. Healthy bone displays punctate bleeding, known as the nutmeg or paprika sign. This is evident even when using a tourniquet. Dead bone is often brittle, and the bone removed by the chisel tends to splinter into small fragments. This is in contrast to cutting healthy bone, which produces bone shavings that tend to curl not dissimilar to wood shavings. The surgeon should be systematic about debridement, covering all areas one at a time, working methodically around the whole zone of infection to ensure all areas are addressed. All metalwork should be tested for integrity. A screwdriver can be used to test if the screws are tight. If loose then they should be removed. All dead bone and loose implants should be removed. Following debridement, and after ensuring removal of all non-viable tissue, the region is irrigated to reduce the bacterial load. Saline is widely used for this purpose, but various fluids have been proposed. Standard antiseptic washes are best avoided as they are toxic to host cells in normal concentrations. In our centre, we use a weak 0.05% chlorhexidine aqueous solution which has a reasonable antibacterial action with minimal cytotoxic potential and reserve saline solution for the irrigation of native joints. Other authors have suggested the use of acetic acid for its anti-biofilm effect [40]. The most important factor is the dilution effect of irrigation and the consequent reduction of the residual bacterial load. High pressure irrigation systems, such as pulse lavage are unnecessary and risk causing further soft tissue injury, so are not required in this setting.

18.3.4.3 Dead Space Management Although debridement significantly reduces the microorganism numbers and disrupts the biofilm, there will inevitably be contamination of the whole operative site with residual planktonic bacteria following excision [41]. Any residual bone defects such as old screw holes, nail tracts or bone defects may fill with haematoma allowing organisms to propagate in these environments, permitting recurrent biofilm development. Systemic

18  Infected Nonunions Around the Knee

antibiotics alone may not be able to penetrate these relatively avascular regions [42–44], leaving residual metalwork at risk of colonisation and reestablishment of a mature biofilm infection. The dosing of systemic antibiotics is limited by the potential toxic effects they may have on organs, such as the kidneys. In contrast local antibiotic carriers can significantly reduce the dead space and deliver high concentrations of local antibiotics, often in the order of 10–100 times the minimum inhibitory concentration of the organisms present [45, 46], and potentially above the mean biofilm eradication concentration. Polymethyl-methacrylate cement (PMMA) has been used for this purpose as beads formed on a wire or as moulded blocks [47–49]. This strategy can be used in cases where staged surgery is contemplated. Bone defects are filled with antibiotic containing PMMA, and once the infection has been eradicated, the PMMA is removed during the second stage reconstruction operation. The disadvantage posed by PMMA is that staged surgery may be challenging, particularly if the soft tissues are of poor quality. Staged surgery prolongs the time a patient must wait before reconstruction is undertaken, and in this time bone ingrowth will be impeded by the PMMA within the defect [50]. Furthermore, there is some concern about the potential for PMMA to become a nidus for secondary infection once all the antibiotic has eluted [51, 52], as well as the risks of multidrug-resistant organisms developing in response to the selection pressure generated by the prolonged antibiotic release below the minimum inhibitory concentration encountered with PMMA [41, 53]. Some surgeons still advocate repeated surgical debridement in severe infection, but this comes with the risk of superinfection and is rarely required as long as the initial debridement is undertaken carefully [7]. There is now increasing use of biodegradable antibiotic carriers, which allow elution of antibiotics at high concentrations whilst they dissolve over several weeks, negating the need for further surgery for removal (see Fig. 18.4d). This makes their use as an adjunct in infected nonunion attractive, particularly when internal fixation is

171

retained or exchanged, to prevent further establishment of new biofilm infection on the implants. Animal studies have demonstrated dissolving local antibiotic carriers are effective for treating infection [54–61], and good outcomes have been achieved in osteomyelitis in humans with ceramic antibiotic carriers [62–70]. There is now some experience of coating implants with local antibiotic carriers to prevent infection during revision arthroplasty surgery [71]. Another strategy is the use of an antibiotic-loaded fast-resorbing hydrogel coating, known as Defensive Antibacterial Coating (DAC), which has been used to coat fracture fixation before insertion in an effort to prevent infection. A recent multicentre trial involving 253 patients investigated its use in closed fracture fixation and demonstrated a significant reduction in subsequent infection in cases when DAC was used [72]. Coatings like this may have a place in internal fixation of infected nonunion in the future. The dead space may also be abolished by performing acute shortening of the bone defect and subsequent lengthening at another site when using the Ilizarov method (see Fig. 18.2).

18.3.4.4 Stability A common error in the management of infected nonunions is the removal of implants to treat infection without then providing sufficient continuing stability. Uncontrolled motion at the nonunion site can result in continuing soft-tissue trauma, interrupted neovascularisation, haematoma formation, reduced vascularity and increased dead space formation  – an environment in which bacteria are more likely to thrive [1, 27]. Stability is important in both fracture infection prevention and treatment [1]. A rabbit model demonstrated higher rates of osteomyelitis in unstabilised open fractures compared to those that were stabilised [73]. If the vascularity of the nonunion is preserved and the stability is maintained, nonunions are able to progress to union even in the face of on-going infection [74]. Berkes et al. found successful union was achieve in 86/123 cases (71%) if debridement and reten-

J. Ferguson et al.

172

a

e

b

c

f

d

g

Fig. 18.4  A 51-year-old man with an infected nonunion of a high tibial osteotomy (a). Presented 3 months after fixation with obvious infection and treated with debridement and VAC therapy. Subsequent further flares of infection with resultant nonunion at 8 months on CT precipitating referral to our centre (b). The plate was removed, and the previous osteotomy site and screw holes

were debrided (c) and filled with a gentamicin-loaded biodegradable carrier to manage the dead space (d). Stability was achieved using a simple Ilizarov frame for eight weeks to allow full weight-bearing and rehabilitation of the knee joint (e, f). Radiograph showing good healing at 4 months after plate removal and debridement (g)

tion of stable fracture implants was instigated within 6 weeks of initial fixation followed by culture-specific antibiotics [1]. In this study intramedullary nail retention was significantly more likely to result in failure. Nails are inherently less stable constructs compared to plates and may have a larger dead space which is more difficult to manage. Unfortunately in established infected nonunion, implant loosening or nonunion instability is more common, so there is often a need for removal of the metalwork and often an exchange to external fixation.

External Fixation In most centres definitive stabilisation is most commonly achieved using external fixation in infected nonunion. The Ilizarov technique is an attractive treatment as it is usually possible to provide good stability to the infected nonunion and address accompanying axis deformity or leg length inequality. Frame constructs should allow early weight-bearing, to facilitate rehabilitation of joints. Monolateral fixation may be less appropriate around the knee as pin placement in soft metaphyseal bone can be less stable.

18  Infected Nonunions Around the Knee

173

It is safe to perform external fixation at the same time as free flap coverage if required [75–77]. Preoperative planning with the plastic surgeons is important to allow construction of the frame so that it allows access for the free flap anastomosis and avoids pin and wire impingement upon the pedicle if bone transport is undertaken [36]. Internal Fixation In certain situations internal fixation has been considered in the management of infected nonunion (see Fig. 18.5). This could be undertaken a

b

d

e

Fig. 18.5  Complex infected nonunion of distal femur in a 46-year-old lady. Failure of internal fixation 4 months following fixation (a, b). Plate was removed, and referring centre applied hybrid external fixator (c), but this was not tolerated and removed when union was not progressing. At time of referral 2 years following original injury, there was established painful, mobile infected nonunion of

either acutely following debridement or after a period of time with external fixation and antibiotics. Arguably the use of internal fixation may be more convenient for patients compared with external fixation, particularly when frame treatment is expected to be prolonged to secure union. However, there is evidence that internal fixation does carry a higher risk of infection recurrence compared to external fixation. Klemm et al. reported a 37.5% failure rate with tibial nailing of infected nonunions [78], and Bose et al. noted an infection recurrence rate of c

f

femur (d, e). Given high BMI and leg circumference, an Ilizarov frame was contraindicated. Following microbiological sampling and debridement, an antegrade nail was inserted with additional support provided by monolateral external fixator (f, g). The external fixator was removed 4 months later. Final imaging 3 years following surgery. The patient was pain-free and fully weight-bearing (h, i)

J. Ferguson et al.

174

g

h

i

Fig. 18.5 (continued)

29% in those treated with internal fixation, compared to 3.5% for those treated with external fixation [36]. In another study exchange tibial nailing for infected nonunion was relatively unsuccessful after a single exchange with a standard uncoated nail with union achieved in only 35.4% of cases, rising to 61.3% after two exchanges [79]. They concluded that Ilizarov methods may be the preferred option in infected cases. Attempts have been made to ameliorate this problem using antibiotic-coated nails. Conway et  al. used antibiotic-coated nails to treat long-­ bone infected nonunions [80]. Although there was an eventual 100% infection eradication rate reported at final follow-up, there was a 40% reoperation rate and a 30% infection recurrence rate requiring further surgery. Furthermore 93% of those with an associated bone defect required a repeat operation, whilst there was no infection recurrence in cases without a bone defect. This may strengthen the argument for Ilizarov techniques when infected nonunion is associated with a bone defect.

The prerequisites for considering internal fixation for infected nonunion include good bone stock, a healthy host and a good soft-tissue envelope. Some would argue that polymicrobial or resistant organisms would also be a contraindication to its use. We would recommend that if undertaking internal fixation of an infected nonunion it be used in combination with a local antibiotic carrier to try and prevent the biofilm from reforming on the metalwork.

18.3.4.5 Soft-Tissue Cover Historically the paradigm for surgical management of osseous infection underlined the need for serial debridement and repeated wound “washouts”. This fear of closing a wound in the context of infection has led to unnecessary repeated operations and consequent delay and prolonged hospital stays for patients with no improvement in outcome [8]. Closure of wounds is safe following adequate debridement and can be achieved with either direct closure or using local or free muscle flaps in the same operation [36, 68, 70]. Leaving a

18  Infected Nonunions Around the Knee

wound open will allow colonisation by microorganisms and increase the risk of multidrug resistance due to the selection pressure caused by the use of antimicrobials. If definitive cover is not possible at the time of debridement for logistical reasons, the wound should be covered with an occlusive or negative-pressure dressing as a temporary measure and definitive closure planned for as soon as possible or at the very latest within 7 days so as to minimise colonisation and superinfection of the wound. In definitive management of infected nonunion, it is preferable to perform a direct wound closure at the end of surgery. This is more often possible in the femur. If the soft tissues do not allow direct closure, then a muscle flap can be used with an unmeshed split skin graft. A local gastrocnemius muscle flap is an option for proximal tibial soft-tissue defects and may also be used in the reconstruction of the extensor mechanism. Free muscle flaps are required for larger defects, particularly in the tibia. The workhorse flap is the free gracilis muscle, although the latissimus dorsi muscle may be used for very large defects.

18.3.4.6 Systemic Antibiotic Therapy Systemic antibiotics are commenced once intraoperative sampling has been completed. An empiric regime is continued until the initial culture results are available. Once a fracture-related infection has been confirmed and the organism is known, a more targeted antibiotic regime may be continued. If complete resection of the infected area is achieved, then antibiotics are often stopped after 6 weeks. However, with the use of internal fixation and in the context of nonunion, it is common to continue antibiotic until bony union has been achieved. At this point antibiotic are stopped, and a decision is made about whether to remove the internal fixation. There is increasing evidence that oral antibiotics are as effective as intravenous antibiotics for patients with susceptible organisms, potentially making the administration of antibiotics cheaper and more straightforward [81].

175

18.3.5 Specific Surgical Techniques for Managing Bone Defects in Infected Nonunion 18.3.5.1 Ilizarov Reconstruction Ilizarov pioneered the theory of “tension stress” allowing bone and soft-tissue generation to correct malalignment and restore defects seen in nonunion [82–88]. The Ilizarov method includes several monofocal and bifocal techniques, which permit deformity correction, allow early weight-­ bearing and joint rehabilitation and allow healing of the infected nonunion [77, 89, 90]. By providing stability and through distraction osteogenesis, new vascularised bone is formed without the need to use avascular bone graft or internal fixation. Ilizarov taught that, “infection burns in the flame of regeneration”, and there is good evidence that the associated hyperaemia precipitated by these techniques does aid healing and improve infection clearance. This method is the most reliable for treating infected nonunion. There are four principle techniques described: 1. Monofocal compression: Following debridement the nonunion site is compressed. This is used for mobile nonunions with minimal bone loss. 2. Monofocal distraction: After debridement the nonunion is initially compressed for 1–2 weeks, and then distraction is performed at 1 mm/day until any associated angular deformity or leg-length inequality is addressed. Wire breakage is more common during this technique, but its outcomes are good with comparatively shorter frame times. 3. Bifocal compression/distraction: A segmental excision is performed of the non-viable nonunion. The bone ends are acutely shortened to provide good bone contact (see Fig. 18.2). A corticotomy is then performed at another site in the bone, and after a latent period of 5–7 days distraction is performed at 1  mm/day with lengthening at the distant site to restore the leg length. The maximum safe acute shortening in the tibia is around 4  cm and in the

176

femur around 6 cm, although this assumes the soft tissues remain supple and no scars constrict the neurovascular bundles. If ischemia is seen on shortening, the limb cannot be acutely shortened to bone contact, and bone transport must be undertaken. In the leg, the fibula may require osteotomy to allow shortening. 4. Bone transport: A segmental excision is performed, but the bone is not acutely shortened. A distant corticotomy is performed, and the middle segment of the bone is gradually transported down into the bone defect at 1 mm/day. Once the defect is abolished and the bone ends make contact, the docking site is further compressed to improve stability and aid healing. This technique is the most technically demanding and requires careful planning. The frame must be constructed to allow both transport and docking without impingement of the rings, so that unnecessary frame exchange is avoided. A monolateral external fixator may be used in the femur if there is sufficient bone distal to the nonunion for adequate hold with half pins. If the nonunion is intra-articular or the periarticular bone fragment is small, it is usually necessary to use fine Ilizarov wires to stabilise the distal fragments. The use of fine wires in the distal femur close to the knee can result in restricted range of movement postoperatively and consequent stiffness. To minimise this potential problem, our practice is to use half pins from the posteromedial and posterolateral aspects of the distal femur so that there is no tethering of the anterior knee retinaculum. If using fine wires, the position of the knee should be altered depending on from which direction the wire is passed. When wires are passed from posterior to the knees axis of flexion, the knee should be kept extended. Once the wire is passed into the femur, the knee should be flexed before the wire exits the bone to ensure the knee retinaculum is not tethered and preserve knee flexion range. Olive wires are sometimes used to provide greater stability, particularly in intra-articular nonunions. However, the bone is often osteopenic in the metaphysis, so increasing the crossing

J. Ferguson et al.

angles of wires is a more reliable method for maintaining stability than solely relying on olive wires. It is advisable to span the knee if there is an associated intra-articular nonunion requiring frame stabilisation or if there is ligamentous instability. Slight distraction across the knee is recommended to protect the chondral surfaces. When undertaking a segmental resection, the aim is to convert an infected nonunion into a defect nonunion [7]. This requires that the residual bone is well vascularised to ensure that reliable union occurs. When segmental excision is performed, the frame can be applied before resection to stabilise the leg. The bone ends should be cut parallel to allow a good contact surface area. The corticotomy is undertaken through a minimal 1–2  cm incision, and care is taken to preserve the periosteum. In the tibia, the incision should not be placed on the subcutaneous border of the tibia but rather about one thumb’s breadth lateral to the crest. The cortex can be pre-drilled to facilitate the final completion with an osteotome. The corticotomy may be delayed some weeks following the infection resection, particularly if the infection is found to be extensive or after infected nail removal, so as to minimise the risk of infection occurring in the lengthening site. In the femur the closer the corticotomy is made to the knee, the higher the risk of stiffness in the joint. A mid-diaphyseal corticotomy is preferred, to allow good proximal fixation and good bone formation. Distraction is performed in four increments of 0.25 mm/day. The rate of the correction depends on the age of the individual and the quality of the regenerating bone as monitored on serial radiographs during follow-up. Monitoring of knee movement is important, and if joint stiffness develops it may be necessary to temporarily slow or stop lengthening to allow aggressive physiotherapy to regain range. A recent systematic review of Ilizarov treatment in infected nonunion of the femur and tibia reviewing 24 studies found an average bone union rate of 97.3% and an infection recurrence rate of 5% [91]. It also found a 4% refracture rate,

18  Infected Nonunions Around the Knee

a 7% malunion rate, a 12% rate of knee stiffness and a 4% amputation rate. The main challenge faced with the Ilizarov technique is the careful follow-up required to identify and treat any obstacles that may develop. Joint stiffness, pin site infections or wire breakage should be dealt with rapidly so that they do not develop into permanent complications. This patient support system is most important and is why cases like this are best treated in dedicated centres with multidisciplinary teams experienced in addressing these issues.

18.3.5.2 Free Vascularised Fibula Transfer This technique involves resecting the contralateral fibula and anastomosing its blood supply at the donor site. This provides vascularised bone capable of healing. Combined working between orthopaedic and plastic surgeons with competence in microvascular techniques is required to undertake this technique. The transferred bone requires good stability to unite and hypertrophy. This is often provided by wedging the fibula into the bone defect and using an Ilizarov frame to compress the site. Internal fixation can be used, but locking plates often result in stress shielding of the transferred fibula, preventing hypertrophy. A very long time (in the order of 2–3 years) may be required to allow the fibula to sufficiently hypertrophy to avoid complications related to stress fracture. This issue has caused some to move away from using free fibula reconstruction in the lower limb due to the significant mismatch in diameter of the donor and recipient bone that results in a relatively high rate of nonunion or stress fracture [41]. 18.3.5.3 T  he Induced Membrane Technique Masquelet originally described this technique, which aimed to recreate an environment favourable for healing through creation of a fibrovascular membrane in which bone grafting could be used [92]. Once the bone segment is excised, a temporary PMMA spacer is inserted into the defect, with an effort made to overlap the bone ends to facilitate later graft incorporation. Care must be taken to ensure the PMMA does not

177

excessively heat the bone as this can cause thermal necrosis that will impede healing and risk persistent infection. The soft tissues are then closed around it. The spacer is then removed 4–8 weeks later preserving the new membrane formed around the spacer. Autologous bone graft is packed into the cavity with the membrane closed around it. The region is then stabilised, usually with an external fixator for infected cases, although plating and nails have also been used. Karger et al. reported a series of 84 cases, of which 50% were infected [93]. Union was obtained in 90%, but it was noted that this was after a mean of 6.11 interventions and a mean of 14.4 months after the first stage reconstruction. Furthermore, the authors advised that weight-­ bearing was delayed until union had been achieved at a mean of 17.4 months. Morelli et al. reviewed 17 papers on induced-­ membrane technique although only 137 of the 427 cases reported had individual patient data [94]. The bone defects measured between 0.6 and 26  cm and 55.5% were for septic bone defect. Union was achieved in 89.7%, with 91.1% infection-­ free. However, union was seen at a mean of 9.4 months (range 6 weeks to 4.4 years) with a 49.6% complication rate.

18.3.5.4 The Papineau Technique Papineau proposed a technique [95, 96], involving radical excision and autogenous bone grafting of the defect followed by non-adherent wound dressing to allow gradual granulation of the skin defect. This is rarely used in modern osteomyelitis treatment as the quality of the skin healing is usually poor, with unstable scaring, and the bone consolidation is unreliable.

18.3.6 When to Consider Endoprosthetic Replacement Joint replacement may be considered when there is significant traumatic chondral damage or extensive chondrolysis as a result of septic arthritis or when there is an unreconstructable intra-­ articular infected nonunion. In young patients this treatment strategy is considered a last resort because of concerns about the

J. Ferguson et al.

178

long-term survival of a prosthetic joint. Even when radiographs demonstrate significant joint damage, suggesting a poor outcome, it is often surprising how well the knee can function following dedicated physiotherapy and rehabilitation, as long as the overall mechanical axis is maintained (see Fig. 18.6). However, if there are very large defects with loss of more than half of the femoral or tibial articulating surface or if it appears that the best that could be achieved with reconstruction is going to be a very stiff, painful or unstable joint, then arthroplasty should be considered. This must be weighed up against the increased risk of infection recurrence, wear rate and need for revision procedures in these often very active young patients. In older, lower-demand patients, endoprosthetic replacement may therefore be more attractive. It may also offer a quicker route to recovery,

a

e

b

avoiding a prolonged reconstruction. If bone stock is of poor quality due to osteopenia, fixation can be very challenging. Although single stage surgery is possible, most surgeons would prefer to undertake a staged approach, with debridement and excision of the infection, placement of an antibiotic-loaded spacer and restoration of the soft-tissue envelope, followed by culture-directed antibiotics. Once there was evidence of the infection being eliminated based on clinical parameters and normalising inflammatory markers, the definitive implant can be inserted. Specific antibiotics can be added to the PMMA spacer based on the previous microbiological results. Often revision or tumour-­ type endoprosthetic implants are required due to the associated bone defects or ligamentous incompetence resulting from infection (see

c

f

Fig. 18.6  A 35-year-old male with early infection following plating of tibial plateau fracture. Referring centre removed plates early which resulted in articular surface displacement and the knee drifting into varus (a, b). A CT showed extensive joint damage without solid union (c, d). A Taylor Spatial Frame (e) was used to correct the

d

g

h

mechanical axis deviation (f) and was removed after 5 months. One year following frame removal, there was minimal pain and a range of movement of 0–105° (g, h). The knee continues to function reasonably well and has not yet required a joint replacement after 9 years

18  Infected Nonunions Around the Knee

a

b

179

c

d

e

Fig. 18.7  An 83-year-old diabetic lady underwent a lateral plateau fracture plating with a synthetic bone graft substitute. There was early infection with lateral plateau collapse (a, b). The plate was removed, but there was also associated septic arthritis. Marked valgus and knee insta-

bility limited mobility (c). A complex primary knee was undertaken following excision of the nonunion to restore the mechanical axis (d, e). Intraoperative frozen section suggested no active infection remained following debridement so this was undertaken as a single-stage procedure

Fig. 18.7). In the extremely frail patient, a single stage radical excision (to ensure complete resection of biofilm) and implantation of massive hinged endoprosthesis may be the quickest route to early mobilisation and return to function.

persistent infection following arthrodesis. Custom-made long intramedullary nails have been used with antegrade insertion, but residual leg length inequality is often a problem, with Bargiotas et  al. reporting a mean shortening of 5.5  cm in their series [1]. Intercalary implants consisting of a modular implant using a metal collar to connect a retrograde femoral nail component and an antegrade tibial nail component may facilitate insertion and leg length equalisation, but the large metal collar may impede bone fusion, and in one series the infection rate was 29% [102]. In a series of 61 patients, Mabry et  al. showed infection rates were lower when using external fixation compared to internal fixation, but whatever method used there was a 40% complication rate [103]. Arthrodesis use for the late consequences of infected nonunion may offer specific challenges given that the bone loss may be more extensive. When using internal fixation, it may be preferable to consider staged surgery with the initial use of an antibiotic-eluting PMMA spacer, followed by second stage internal fixation only once there is sufficient evidence of infection eradication during follow-up. The Ilizarov method for knee arthrodesis offers the additional advantage of being able to correct associated limb length inequality at the same time [104]. Above knee amputation is another last-resort option if reconstruction of knee function or

18.3.7 Knee Arthrodesis vs. Above Knee Amputation If after multiple revision operations septic failure remains and especially when there is significant knee functional impairment with bone and/or soft-tissue damage, knee stiffness and associated incompetence of the extensor mechanism, a reconstruction or arthroplasty might be impossible. In these rare cases, last-resort procedures to regain mobility and quality of life include an above knee amputation or knee arthrodesis. A variety of fusion techniques have been described, using both internal and external ­fixation, mainly in the treatment of recalcitrant prosthetic joint infection [1, 97–101]. Arthrodesis using an intramedullary nail in active infection has been shown to be associated with a higher risk of persistent infection and poorer functional outcome. Röhner et al. investigated arthrodesis using a nail in 26 patients with prosthetic joint infection and found 50% had persistent infection [101]. When using an intramedullary device, it is important to ensure that removal is possible if there is

J. Ferguson et al.

180

control of infection fails. Above knee amputation is associated with poor functional outcome and low ambulation rates. The literature comparing knee arthrodesis and above knee amputation complication rates, functionality and quality of life are scarce [99, 100, 105]. The energy expenditure required to power an above knee prosthesis is significant, and in several studies ambulation rates following above knee amputation are low. Sierra et al. found that only 6/18 (33%) with an above knee amputation for prosthetic joint infection were fitted with a prosthesis and only 3/18 (17%) were able to walk at final follow-up [97]. Pring et al. found that only 7/23 (30%) with an above knee amputation were daily walkers and 20/23 (87%) used a wheelchair for at least part of the day [106]. Interestingly the complication rate of 31–32% seen following above knee amputations [97, 98] is similar to the complication rate of 30–50% seen in knee arthrodesis [99, 101]. In these situations it is most important to include the patient in the decision-making process and involve expert rehabilitation specialists to give realistic expectations of what can and cannot be achieved with an amputation prosthesis.

18.3.8 Conclusion Infected nonunion around the knee is a challenging problem to address. Particular difficulties faced relate to the potential for stiffness, malalignment and chondral injury. We have discussed the important principles of infection management, namely, adequate microbiological sampling to guide treatment, early aggressive management of acute infection, the need for thorough debridement, management of the dead space, stabilisation of the nonunion and adequate soft-tissue cover. Many of the more complex infected nonunions are better managed in dedicated specialist centres with the availability of a multidisciplinary team and the logistical backup required for the careful follow-up required in these cases. Despite the potential dreadful complications that can ensue, amputation is rarely indicated for infected nonunion.

References 1. Pollard TC, Newman JE, Barlow NJ, Price JD, Willett KM.  Deep wound infection after proximal femoral fracture: consequences and costs. J Hosp Infect. 2006;63(2):133. 2. Olesen UK, Pedersen NJ, Eckardt H, Lykke-Meyer L, Bonde CT, Singh UM, McNally M. The cost of infection in severe open tibial fractures treated with a free flap. Int Orthop. 2017;41(5):1049–55. 3. Darouiche RO.  Treatment of infections associated with surgical implants. N Engl J Med. 2004;350(14):1422–9. 4. Napierala MA, Rivera JC, Burns TC, Murray CK, Wenke JC, Hsu JR, Consortium STRE.  Infection reduces return-to-duty rates for soldiers with type III open tibia fractures. J Trauma Acute Care Surg. 2014;77(3):S194–7. 5. Metsemakers WJ, Kortram K, Morgenstern M, Moriarty TF, Meex I, Kuehl R, et  al. Definition of infection after fracture fixation: a systematic review of randomized controlled trials to evaluate current practice. Injury. 2018;49(3):497–504. 6. McNally M, Govaert G, Dudareva M, Morgenstern M, Metsemakers W-J. Definition and diagnosis of fracture-related infection. EFORT Open Rev 2020;5:614– 619. https://doi.org/10.1302/2058-5241.5.190072. 7. Lammens J, Ochsner PE, McNally M. Infected nonunion. In: Kates SL, Borens O, editors. Principles of orthopedic infection management. New  York: AO Foundation, Thieme; 2017. p. 167–88. 8. Trampuz A, Zimmerli W. Diagnosis and treatment of infections associated with fracture-fixation devices. Injury. 2006;37(2):S59–66. 9. Gustilo RB, Anderson JT. Prevention of infection in the treatment of one thousand and twenty-five open fractures of long bones: retrospective and prospective analyses. JBJS. 1976;58(4):453–8. 10. Zalavras CG, Marcus RE, Levin LS, Patzakis MJ.  Management of open fractures and subsequent complications. JBJS. 2007;89(4):884–95. 11. Patzakis MJ, Wilkins J. Factors influencing infection rate in open fracture wounds. Clin Orthop Relat Res. 1989;243:36–40. 12. Fang C, Wong T-M, Lau T-W, To KK, Wong SS, Leung F. Infection after fracture osteosynthesis—part I: pathogenesis, diagnosis and classification. J Orthop Surg. 2017;25(1):2309499017692712. 13. Young S, Lie SA, Hallan G, Zirkle LG, Engesæter LB, Havelin LI. Risk factors for infection after 46,113 intramedullary nail operations in low-and middle-­ income countries. World J Surg. 2013;37(2):349–55. 14. Bhattacharyya T, Mehta P, Smith M, Pomahac B.  Routine use of wound vacuum-assisted closure does not allow coverage delay for open tibia fractures. Plast Reconstr Surg. 2008;121(4):1263–6. 15. Sendi P, McNally MA.  Wound irrigation in ini tial management of open fractures. N Engl J Med. 2016;374(18):1788.

18  Infected Nonunions Around the Knee 16. Metsemakers W-J, Handojo K, Reynders P, Sermon A, Vanderschot P, Nijs S. Individual risk factors for deep infection and compromised fracture healing after intramedullary nailing of tibial shaft fractures: a single centre experience of 480 patients. Injury. 2015;46(4):740–5. 17. Metsemakers WJ, Kuehl R, Moriarty TF, Richards RG, Verhofstad MHJ, Borens O, et al. Infection after fracture fixation: current surgical and microbiological concepts. Injury. 2018;49(3):511–22. 18. Bowen TR, Widmaier JC.  Host classification predicts infection after open fracture. Clin Orthop Relat Res. 2005;433:205–11. 19. Castillo RC, Bosse MJ, MacKenzie EJ, Patterson BM, LEAP Study Group. Impact of smoking on fracture healing and risk of complications in limb-­ threatening open tibia fractures. J Orthop Trauma. 2005;19(3):151–7. 20. Høiby N, Bjarnsholt T, Givskov M, Molin S, Ciofu O.  Antibiotic resistance of bacterial biofilms. Int J Antimicrob Agents. 2010;35(4):322–32. 21. Zimmerli W, Moser C.  Pathogenesis and treatment concepts of orthopaedic biofilm infections. FEMS Immunol Med Microbiol. 2012;65(2):158–68. 22. Stewart PS, Costerton JW.  Antibiotic resistance of bacteria in biofilms. Lancet. 2001;358(9276): 135–8. 23. Donlan RM.  Biofilms: microbial life on surfaces. Emerg Infect Dis. 2002;8(9):881. 24. Wright JA, Nair SP. Interaction of staphylococci with bone. Int J Med Microbiol. 2010;300(2):193–204. 25. Elek SD, Conen PE. The virulence of staphylococcus pyogenes for man. A study of the problems of wound infection. Br J Exp Pathol. 1957;38(6):573. 26. Zimmerli W, Waldvogel FA, Vaudaux P, Nydegger UE. Pathogenesis of foreign body infection: description and characteristics of an animal model. J Infect Dis. 1982;146(4):487–97. 27. Schmidt AH, Swiontkowski MF. Pathophysiology of infections after internal fixation of fractures. J Am Acad Orthop Surg. 2000;8(5):285–91. 28. Willenegger H, Roth B.  Treatment tactics and late results in early infection following osteosynthesis. Unfallchirurgie. 1986;12(5):241–6. 29. Ochsner PE, Sirkin MS, Trampuz A.  Acute infection. In: Rüedi T, Buckley RE, Moran CG, editors. AO principles of fracture management. Stuttgart: Thieme; 2007. p. 520–40. 30. McNally M, Sendi P.  Implant-associated osteomyelitis of long bones. In: Zimmerli W, editor. Bone and joint infections: from microbiology to diagnostics and treatment. Oxford: Wiley; 2015. p. 303–23. 31. Kohan AA, Rubbert C, Vercher-Conejero JL, Partovi S, Sher A, Kolthammer JA, et  al. The impact of orthopedic metal artifact reduction software on interreader variability when delineating areas of interest in the head and neck. Pract Radiat Oncol. 2015;5(4):e309–15. 32. Radionuclide imaging after skeletal interventional procedures; Semin Nucl Med. 1995;25(1):3–14.

181 33. Govaert GA, IJpma FF, McNally M, McNally E, Reininga IH, Glaudemans AW. Accuracy of diagnostic imaging modalities for peripheral post-traumatic osteomyelitis—a systematic review of the recent literature. Eur J Nucl Med Mol Imaging. 2017; 1–15. 34. Dudareva M, Hotchen AJ, Ferguson J, Hodgson  S, Scarborough M, Atkins BL, McNally MA. The microbiology of osteomyelitis: changes over ten years. J Infection. 2019;79:189–198. 35. Weber BG, Čech O.  Pseudarthrosis: pathophysiology, biomechanics, therapy, results. Grune & Stratton; 1976. 36. Bose D, Kugan R, Stubbs D, McNally M.  Management of infected nonunion of the long bones by a multidisciplinary team. Bone Joint J. 2015;97-B(6):814–7. 37. McNally M.  Infection after fracture. In: Kates SL, Borens O, editors. Principles of orthopedic infection management. New  York: AO Foundation, Thieme; 2017. p. 139–66. 38. McNally M, Nagarajah K.  Osteomyelitis. Orthop Trauma. 2010;24(6):416–29. 39. Patzakis MJ, Zalavras CG.  Chronic posttraumatic osteomyelitis and infected nonunion of the tibia: current management concepts. J Am Acad Orthop Surg. 2005;13(6):417–27. 40. Bjarnsholt T, Alhede M, Jensen P, Nielsen AK, Johansen HK, Homøe P, et  al. Antibiofilm properties of acetic acid. Adv Wound Care. 2015;4(7): 363–72. 41. Ferguson J, Diefenbeck M, McNally M.  Ceramic biocomposites as biodegradable antibiotic carriers in the treatment of bone infections. J Bone Joint Infect. 2017;2(1):38–51. 42. Schmidmaier G, Lucke M, Wildemann B, Haas NP, Raschke M.  Prophylaxis and treatment of implant-­ related infections by antibiotic-coated implants: a review. Injury. 2006;37(2):S105–12. 43. Metsemakers WJ, Moriarty TF, Nijs S, Pape HC, Richards RG.  Influence of implant properties and local delivery systems on the outcome in operative fracture care. Injury. 2016;47(3):595–604. 44. Tøttrup M, Bue M, Koch J, Jensen LK, Hanberg P, Aalbæk B, et  al. Effects of implant-associated osteomyelitis on cefuroxime bone pharmacokinetics: assessment in a porcine model. JBJS. 2016;98(5):363–9. 45. Mayberry-Carson KJ, Tober-Meyer B, Smith JK, Lambe DW, Costerton JW. Bacterial adherence and glycocalyx formation in osteomyelitis experimentally induced with staphylococcus aureus. Infect Immun. 1984;43(3):825–33. 46. Walenkamp GH, Vree TOMB, Van Rens TJ. Gentamicin-PMMA beads: pharmacokinetic and nephrotoxicological study. Clin Orthop Relat Res. 1986;205:171–83. 47. Buchholz HW, Elson RA, Heinert K.  Antibiotic-­ loaded acrylic cement: current concepts. Clin Orthop Relat Res. 1984;190:96–108.

182

J. Ferguson et al.

48. Cho S-H, Song H-R, Koo K-H, Jeong S-T, Park 62. Fleiter N, Walter G, Bösebeck H, Vogt S, Büchner H, Hirschberger W, Hoffmann R.  Clinical use and Y-J.  Antibiotic-impregnated cement beads in the safety of a novel gentamicin-releasing resorbable treatment of chronic osteomyelitis. Bull (Hosp Joint bone graft substitute in the treatment of osteomyeliDis (New York, NY)) 1997;56(3):140. tis/osteitis. Bone Joint Res. 2014;3(7):223–9. 49. Evans RP, Nelson CL.  Gentamicin-impregnated polymethylmethacrylate beads compared with 63. McKee MD, Wild LM, Schemitsch EH, Waddell JP.  The use of an antibiotic-impregnated, systemic antibiotic therapy in the treatment of osteoconductive, bioabsorbable bone substitute in ­ chronic osteomyelitis. Clin Orthop Relat Res. the treatment of infected long bone defects: early 1993;295:37–42. results of a prospective trial. J Orthop Trauma. 50. Walenkamp GHIM, Kleijn LLA, de Leeuw 2002;16(9):622–7. M.  Osteomyelitis treated with gentamicin-PMMA beads: 100 patients followed for 1-12 years. Acta 64. Gitelis S, Brebach GT.  The treatment of chronic osteomyelitis with a biodegradable antibiotic-­ Orthopaedica. 1998;69(5):518–22. impregnated implant. J Orthop Surg Hong Kong. 51. Neut D, van de Belt H, van Horn JR, van der Mei 2002;10(1):53–60. HC, Busscher HJ.  Residual gentamicin-release from antibiotic-loaded polymethylmethacrylate 65. Chang W, Colangeli M, Colangeli S, Di Bella C, Gozzi E, Donati D.  Adult osteomyelitis: debridebeads after 5 years of implantation. Biomaterials. ment versus debridement plus osteoset T® pellets. 2003;24(10):1829–31. 52. Kendall RW, Duncan CP, Smith JA, Ngui-Yen Acta Orthopaedica Belgica. 2007;73(2):238–44. JH.  Persistence of bacteria on antibiotic loaded 66. McKee MD, Li-Bland EA, Wild LM, Schemitsch acrylic depots: a reason for caution. Clin Orthop EH.  A prospective, randomized clinical trial comRelat Res. 1996;329:273–80. paring an antibiotic-impregnated bioabsorbable 53. Von Eiff C, Lindner N, Proctor RA, Winkelmann W, bone substitute with standard antibiotic-impregnated Peters G. Development of gentamicin-resistant small cement beads in the treatment of chronic osteocolony variants of S.  Aureus after implantation of myelitis and infected nonunion. J Orthop Trauma. gentamicin chains in osteomyelitis as a possible 2010;24(8):483–90. cause of recurrence. Zeitschrift Fur Orthopadie Und 67. Humm G, Noor S, Bridgeman P, David M, Bose Ihre Grenzgebiete. 1997;136(3):268–71. D.  Adjuvant treatment of chronic osteomyeli 54. Turner TM, Urban RM, Hall DJ, Chye PC, tis of the tibia following exogenous trauma using Segreti J, Gitelis S.  Local and systemic levels of OSTEOSET®-T: a review of 21 patients in a tobramycin delivered from calcium sulfate bone regional trauma centre. Strat Trauma Limb Reconstr. graft substitute pellets. Clin Orthop Relat Res. 2014;9(3):157–61. 2005;437:97–104. 68. Ferguson JY, Dudareva M, Riley ND, Stubbs D, 55. Cornell CN, Tyndall D, Waller S, Lane JM, Brause Atkins BL, McNally MA.  The use of a biodegradBD.  Treatment of experimental osteomyelitis with able antibiotic-loaded calcium sulphate carrier antibiotic-impregnated bone graft substitute. J containing tobramycin for the treatment of chronic Orthop Res. 1993;11(5):619–26. osteomyelitis a series of 195 cases. Bone Joint J. 56. Korkusuz F, Uchida A, Shinto Y, Araki N, Inoue K, 2014;96(6):829–36. Ono K. Experimental implant-related osteomyelitis 69. Romanò CL, Logoluso N, Meani E, Romanò D, treated by antibiotic-calcium hydroxyapatite ceramic De Vecchi E, Vassena C, Drago L.  A comparacomposites. Bone Joint J. 1993;75(1):111–4. tive study of the use of bioactive glass S53P4 and 57. Shirtliff ME, Calhoun JH, Mader JT. Experimental antibiotic-­loaded calcium-based bone substitutes in osteomyelitis treatment with antibiotic-­ the treatment of chronic osteomyelitis. Bone Joint J. impregnated hydroxyapatite. Clin Orthop Relat Res. 2014;96(6):845–50. 2002;401:239–47. 70. McNally MA, Ferguson JY, Lau ACK, Diefenbeck 58. Thomas DB, Brooks DE, Bice TG, DeJong ES, M, Scarborough M, Ramsden AJ, Atkins BL. Single-­ Lonergan KT, Wenke JC.  Tobramycin-impregnated stage treatment of chronic osteomyelitis with a calcium sulfate prevents infection in contaminated new absorbable, gentamicin-loaded, calcium sulwounds. Clin Orthop Relat Res. 2005;441:366–271. phate/hydroxyapatite biocomposite. Bone Joint J. 59. Wenke JC, Owens BD, Svoboda SJ, Brooks 2016;98(9):1289–96. DE.  Effectiveness of commercially-available 71. Logoluso N, Drago L, Gallazzi E, George DA, antibiotic-­impregnated implants. J Bone Joint Surg Morelli I, Romanò CL.  Calcium-Based, antibiotic-­ Br. 2006;88(8):1102–4. loaded bone substitute as an implant coating: a 60. Yarboro SR, Baum EJ, Dahners LE. Locally adminpilot clinical study. J Bone Joint Infect. 2016;1: istered antibiotics for prophylaxis against surgical 59–64. wound infection. An in vivo study. J Bone Joint Surg 72. Malizos K, Blauth M, Danita A, Capuano N, (Am). 2007;89(5):929–33. Mezzoprete R, Logoluso N, et  al. Fast-resorbable 61. Rand BCC, Penn-Barwell JG, Wenke JC. Combined antibiotic-loaded hydrogel coating to reduce post-­ local and systemic antibiotic delivery improves surgical infection after internal osteosynthesis: a eradication of wound contamination. Bone Joint J. multicenter randomized controlled trial. J Orthop 2015;97(10):1423–7. Traumatol. 2017;1

18  Infected Nonunions Around the Knee 73. Worlock P, Slack R, Harvey L, Mawhinney R. The prevention of infection in open fractures: an experimental study of the effect of fracture stability. Injury. 1994;25(1):31–8. 74. Hofmann GO, Bär T, Bühren V.  The osteosynthesis implant and early postoperative infection: healing with or without removal of the material? Der Chirurg; Zeitschrift Fur Alle Gebiete Der Operativen Medizen. 1997;68(11):1175–80. 75. Anthony JP, Mathes SJ, Alpert BS. The muscle flap in the treatment of chronic lower extremity osteomyelitis: results in patients over 5 years after treatment. Plast Reconstr Surg. 1991;88(2):311–8. 76. May Jr JW, Jupiter JB, Gallico 3rd GG, Rothkopf DM, Zingarelli P.  Treatment of chronic traumatic bone wounds. Microvascular free tissue transfer: a 13-year experience in 96 patients. Ann Surg. 1991;214(3):241. 77. McNally M, Ferguson J, Kugan R, Stubbs D.  Ilizarov treatment protocols in the management of infected nonunion of the tibia. J Orthop Trauma. 2017;31(10):S47–54. 78. Klemm KW. Treatment of infected pseudarthrosis of the femur and tibia with an interlocking nail. Clin Orthop Relat Res. 1986;212:174–81. 79. Tsang STJ, Mills LA, Frantzias J, Baren JP, Keating JF, Simpson A.  Exchange nailing for nonunion of diaphyseal fractures of the tibia. Bone Joint J. 2016;98(4):534–41. 80. Conway J, Mansour J, Kotze K, Specht S, Shabtai L.  Antibiotic cement-coated rods. Bone Joint J. 2014;96(10):1349–54. 81. Li HK, Rombach I, Zambellas R, Walker AS, McNally MA, Atkins BL, Lipsky BA, Hughes HC, Bose D, Kümin M, Scarborough C. Oral versus intravenous antibiotics for bone and joint infection. New England Journal of Medicine. 2019;380(5): 425–36. 82. Paley D, Catagni MA, Argnani F, Villa A, Bijnedetti GB, Cattaneo R.  Ilizarov treatment of tibial nonunions with bone loss. Clin Orthop Relat Res. 1989;241:146–65. 83. Pearson RL, Perry CR. The Ilizarov technique in the treatment of infected tibial nonunions. Orthop Rev. 1989;18(5):609–13. 84. Green SA, Jackson JM, Wall DM, Marinow H, Ishkanian J.  Management of segmental defects by the Ilizarov intercalary bone transport method. Clin Orthop Relat Res. 1992;280:136–42. 85. Cattaneo R, Catagni M, Johnson EE. The treatment of infected nonunions and segmental defects of the tibia by the methods of Ilizarov. Clin Orthop Relat Res. 1992;280:143–52. 86. Saleh M, Royston S.  Management of nonunion of fractures by distraction with correction of angulation and shortening. Bone Joint J. 1996;78(1):105–9. 87. Maini L, Chadha M, Vishwanath J, Kapoor S, Mehtani A, Dhaon BK. The Ilizarov method in infected nonunion of fractures. Injury. 2000;31(7):509–17. 88. Kocaoglu M, Eralp L, Sen C, Cakmak M, Dincyürek H, Göksan SB.  Management of stiff hypertrophic

183 nonunions by distraction osteogenesis: a report of 16 cases. J Orthop Trauma. 2003;17(8):543–8. 89. Ilizarov GA.  Clinical application of the tension-­ stress effect for limb lengthening. Clin Orthop Relat Res. 1990;250:8–26. 90. Shevtsov VI, Makushin VD, Kuftyrev LM. Defects of the lower limb bones. Treatment based on Ilizarov techniques. New Delhi: Churchill Livingstone; 2000. p. 227–438. 91. Yin P, Ji Q, Li T, Li J, Li Z, Liu J, et al. A systematic review and meta-analysis of Ilizarov methods in the treatment of infected nonunion of tibia and femur. PLoS One. 2015;10(11):e0141973. 92. Masquelet AC, Fitoussi F, Begue T, Muller GP. Reconstruction of the long bones by the induced membrane and spongy autograft. Ann Chir Plast Esthet. 2000;45(3):346–53. 93. Karger C, Kishi T, Schneider L, Fitoussi F, Masquelet A-C. Treatment of posttraumatic bone defects by the induced membrane technique. Orthop Traumatol Surg Res. 2012;98(1):97–102. 94. Morelli I, Drago L, George DA, Gallazzi E, Scarponi S, Romanò CL. Masquelet technique: myth or reality? A systematic review and meta-analysis. Injury. 2016;47:S68–76. 95. Papineau LJ. Lexcision-greffe avec fermeture retardée délibérée dans lostéomyélite chronique. Nouv Presse Med. 1973;2(41):2753–5. 96. Green SA, Dlabal TA. The open bone graft for septic nonunion. Clin Orthop Relat Res. 1983;180: 117–24. 97. Sierra RJ, Trousdale RT, Pagnano MW. Above-the-­ knee amputation after a total knee replacement: prevalence, etiology, and functional outcome. JBJS. 2003;85(6):1000–4. 98. Fedorka CJ, Chen AF, McGarry WM, Parvizi J, Klatt BA. Functional ability after above-the-knee amputation for infected total knee arthroplasty. Clin Orthop Relat Res. 2011;469(4):1024–32. 99. Chen AF, Kinback NC, Heyl AE, McClain EJ, Klatt BA.  Better function for fusions versus above-the-knee amputations for recurrent periprosthetic knee infection. Clin Orthop Relat Res. 2012;470(10):2737–45. 100. Wu CH, Gray CF, Lee G-C.  Arthrodesis should be strongly considered after failed two-stage reimplantation TKA.  Clin Orthop Relat Res. 2014;472(11):3295–304. 101. Röhner E, Windisch C, Nuetzmann K, Rau M, Arnhold M, Matziolis G.  Unsatisfactory outcome of arthrodesis performed after septic failure of revision total knee arthroplasty. J Bone Joint Surg Am. 2015;97(4):298. 102. Angelini A, Henderson E, Trovarelli G, Ruggieri P.  Is there a role for knee arthrodesis with modular endoprostheses for tumor and revision of failed endoprostheses? Clin Orthop Relat Res. 2013;471(10):3326–35. 103. Mabry TM, Jacofsky DJ, Haidukewych GJ, Hanssen AD.  The Chitranjan Ranawat Award: comparison of intramedullary nailing and external fixation knee

184 arthrodesis for the infected knee replacement. Clin Orthop Relat Res. 2007;464:11–5. 104. Rozbruch SR, Ilizarov S, Blyakher A. Knee arthrodesis with simultaneous lengthening using the Ilizarov method. J Orthop Trauma. 2005;19(3):171–9.

J. Ferguson et al. 105. Conway JD, Mont MA, Bezwada HP. Arthrodesis of the knee. JBJS. 2004;86(4):835–48. 106. Pring DJ, Marks L, Angel JC. Mobility after amputation for failed knee replacement. Bone Joint J. 1988;70(5):770–1.

Non-infected Nonunions and Malunions Around the Knee

19

Nando Ferreira

Malalignment around the knee may harbour cosmetic, biomechanical and joint longevity complications [1]. Current literature is inconclusive regarding the long-term implications of angular deformities of the lower limb [1–3]; however, long-bone nonunions have shown a reduction in quality of life that is greater than diabetes, stroke and HIV [4]. Fortunately, these complications, following fracture care, are seen less frequently as a result of better understanding of fracture biomechanics and better orthopaedic implant design [5–15]. Despite this, malalignment rates as high as 60% have been reported following intramedullary nailing for proximal tibia fractures in particular [16]. With the advent of modern orthopaedic devices and  more advanced limb salvage and reconstruction techniques, the correction of these malalignments is becoming commonplace in general orthopaedic practices around the world [17–27]. These surgeries however are technically demanding, deal with an anatomical area with abnormal biology and biomechanics and are frequently burdened with high complication rates. The following chapter will aim to provide a general approach to the management of malalign-

N. Ferreira (*) Division of Orthopaedic Surgery, Department of Surgical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa e-mail: [email protected]

ment resulting from non-infected nonunions and malunions around the knee.

19.1 Evaluation of the Problem (Posttraumatic Axis Deviation) The evaluation of a patient with a nonunion or malunion starts with a comprehensive history and thorough clinical examination. Particular attention is paid to any existing condition or complication that may negatively impact the reconstruction process.

19.1.1 History The history of the initial injury and treatment is important. Identifying possible causes for the current nonunion or malunion is the first step to avoid suffering the same complication. Injury characteristics, initial and definitive management, early complications and any concomitant host factors or drugs that could influence fracture management should be investigated. Any history of infective complications should be explored. In nonunion cases, in particular, it is of vital importance to identify cases of previous or current infection. These cases should be designated as Cierny and Mader stage IV chronic osteomyelitis and managed according to chronic osteomyelitis treatment protocols (not discussed here) [28–32].

© Springer Nature Switzerland AG 2021 M. Hanschen et al. (eds.), Knee Fractures, Strategies in Fracture Treatments, https://doi.org/10.1007/978-3-030-81776-3_19

185

N. Ferreira

186

Any concomitant systemic disease should be identified and optimally treated prior to deformity correction surgery. Anaemia, poorly controlled diabetes mellitus, malnutrition and hypothyroidism have all been shown to negatively affect bone healing [33–36]. The effect of HIV and bone healing remains controversial, but as a rule, HIV-positive individuals should be on effective treatment to help maintain general health and wellbeing [37, 38]. Smoking and alcohol use have both been implicated in poor fracture healing [39–47]. Cessation of smoking and moderation of alcohol intake should be encouraged in all patients undergoing any reconstructive procedure. Vitamin D is essential in bone metabolism and has an important role in fracture healing. There is little evidence that supplementation has any effect on fracture healing and cannot be recommended for all patients. For patients who are deficient, however, supplementation to normal levels should be considered [48–52]. Multiple drugs have theoretical implications for bone healing. These include non-steroidal anti-inflammatory drugs, corticosteroids, chemotherapy agents, certain antibiotics, anticoagulants and anticonvulsants [36, 44, 53–56]. Although conflicting evidence and few human trials are available on the effect of these drugs on bone healing, avoidance of medications with potential negative effects should be considered where possible. Taking the time to optimise these modifiable host factors will ultimately result in fewer complications, better tissue histogenesis and an overall shorter treatment time.

19.1.2 Clinical Evaluation A complete general examination includes evaluation of the patient’s gait and culminates in a thorough examination of the entire affected limb. The condition of the soft tissues around the deformity is noted, and the need for soft tissue reconstruction prior to or at the time of bony reconstruction should be considered. Special attention is paid to any sign of previous or ongoing infection.

It is also of vital importance to evaluate  the joints above and below the deformity for reciprocal movement in the opposite direction of the deformity. This will prevent secondary deformity and functional impairment following any deformity correction surgery. Examples include hip adduction contractures in patients with concomitant valgus deformity around the knee, capsular contractures of the knee joint, ankle equines contractures or stiff subtalar deformities. A patient with a recurvatum deformity of the proximal tibia and concurrent knee flexion contracture, for example, might be able to ambulate prior to  the correction of his tibia deformity. Once the tibial deformity is corrected, the flexion contracture of the knee joint will become evident and could lead to functional impairment that might not have been present prior to deformity correction. The clinical examination should include an accurate assessment of the true and apparent leg length discrepancy as well as the rotational profile of the limb. In rare instances, a CT scan might assist with identifying and quantifying rotational deformities that might be present (Fig. 19.1).

19.1.3 Radiological Evaluation A standardised radiological evaluation is necessary for accurate deformity assessment and planning of correction. Radiographic assessment should include full-length AP and lateral views. These images are produced with the X-ray tube 3 m from the cassette and centred on the knees. The image should include the entire pelvis and the ankle joints. The patient is positioned with both feet flat on the ground, standing as upright as possible, and patellas facing forward. Blocks are placed under the short limb to level the pelvis. In addition to the antero-posterior view, a full-length lateral radiograph with the knee in maximal extension is also obtained (Fig. 19.2). These views are ­supplemented with dedicated views of the involved limb segments.  A metal sphere magnification marker is placed at the level of the bone segment of interest for correction of magnification.

19  Non-infected Nonunions and Malunions Around the Knee

187

deformities in older patients. In these cases, constrained designs with stemmed implants are generally preferred. Megaprostheses are typically reserved for cases with significant articular bone loss or very poor bone stock that will not support adequate fixation. A thorough understanding of bone physiology, deformity analysis and correction will help guide the surgeon to the most appropriate deformity correction strategy to employ. Regardless of correction strategy, respect of bone and soft tissues during and after surgery will reward the surgeon with uneventful healing and minimal complications. The conversion of a malunion into a septic nonunion is a significant  complication and should be avoided at all costs.

19.2.1 Deformity Analysis Multiple methods for deformity analysis and planning have been described, but the ultimate goal of all these methods is to identify the location, magnitude and direction at any deformity that is present. The deformity is then described in terms of angulation and translation in the three cardinal/anatomical planes. This will result in a description of any deformity in terms of: Fig. 19.1  Radiograph showing a recurvatum deformity of the proximal tibia of a child following growth arrest of the tibial tubercle apophysis

Figure 19.2.  Full length antero-posterior radiograph with blocks under the right foot and lateral radiograph with maximal knee extension.  Computerised tomography (CT) scans are reserved for cases with complex rotational deformities or in scenarios where custom 3D printed models are considered for planning and surgical rehearsal purposes.

19.2 Preoperative Planning In most cases, patients will require correction of deformity and skeletal stabilisation to allow for bony union. Arthroplasty is reserved for mild

• Translation in the coronal plane (medial/lateral translation) • Angulation in the coronal plane (varus/valgus angulation) • Translation in the sagittal plane (anterior/posterior translation) • Angulation in the sagittal plane (procurvatum/ recurvatum) • Translation in the axial plane (shortening/ lengthening) • Angulation in the axial plane (internal/external rotation) Whatever the preferred method for deformity analysis, the fundamentals remain the same: 1. Identify if any deformity is present (measure the mechanical axis deviation).

N. Ferreira

188 Fig. 19.2  Full length antero-posterior radiograph with blocks under the right foot and lateral radiograph with maximal knee extension

2. Identify the abnormal limb segment (tibia or femur or both). 3. Find the apex of the deformity: intersection of the proximal and distal bone axes. 4. Qualify the deformity in the coronal, sagittal and axial planes.

As we are exclusively discussing nonunions and malunions around the knee, we are mainly dealing with metaphyseal deformities. For this reason, the author suggests the use of mechanical axis planning methods.

Note that deformities might be present in more than one limb segment and that each segment might have more than one deformity. Articular deformities like contractures of the proximal and distal joints might also contribute to the overall axis deviation of the limb. Meticulous clinical evaluation and deformity analysis are required to identify all deformities that are present and might require correction.

19.3 Surgical Approaches and Osteotomies 19.3.1 Nonunion Before embarking on nonunion surgery, contemplation of the reasons for the nonunion is needed if the same mistakes are to be avoided. Variables to consider include the previous injury character-

19  Non-infected Nonunions and Malunions Around the Knee

189

Fig. 19.3  Radiographs of a patient with a proximal tibia stiff hypertrophic nonunion. The sequence of images showing initial deformity followed by gradual correction and distraction with a hexapod circular external fixator. The final image shows the final result following union and removal of the external fixator

istics and treatment, current host physiological status, the condition of the soft tissues and its ability to sustain bone healing, the clinical and radiographic condition of the nonunion site and current functional ability. Various systems have been devised to classify nonunions, each taking specific aspects of these entities into account. The Judet and Judet classification, modified by Weber and Cech, classifies nonunions according to the vascularity of the bone ends into atrophic, oligotrophic or hypertrophic [57, 58]. Ilizarov proposed a classification that designates nonunions as either stiff or mobile depending on the amount of angulation possible at the nonunion site [59]. The Paley classification specifically addresses tibial nonunions and considers bone loss, fracture site mobility, angular deformities and overall bone length [60, 61]. The Wu classification specifically addresses nonunions with internal fixation in situ [62]. The most recent classification proposes the use of the Calori Nonunion Scoring System (NUSS) to designate nonunions into different groups according to their complexity [63, 64]. Regardless of the specific type of nonunion, the fundamentals of management remain unchanged. These management principles include:

1. 2. 3. 4. 5.

Host optimisation Mechanical realignment Stable fixation Biological stimulation Functional rehabilitation

As malalignment usually occurs at the nonunion site, all angular corrections are also ­performed at this site without the need for additional osteotomies. This means that fixations options are often dictated by the nonunion site and configuration. Mobile nonunions are easily treated by acute correction followed by either internal or external skeletal stabilisation [65–67]. Should a limb length discrepancy be present, this can then be addressed by a lengthening procedure away from the nonunion site. Stiff, hypertrophic nonunions frequently have concomitant angular deformities that need to be addressed. An elegant technique that is gaining popularity is the use of closed distraction for the management of these nonunions [17, 24–27, 65, 67–72]. The advantage of this treatment strategy is the correction of both angular deformities and limb length discrepancies while providing stable fixation that supports bone healing and allows immediate functional rehabilitation (Fig. 19.3).

190

19.3.2 Malunion As opposed to nonunions, malunions often provide the attending surgeon with more management options. The location and type of osteotomy can be altered depending on the chosen fixation method and desired effect on limb length.

19.3.3 Osteotomy The decision regarding the location and technique of osteotomy is a crucial step during the planning and correction of any deformity. The effect of the chosen osteotomy technique and location on the overall limb alignment, limb length and healing potential at the osteotomy site should all be considered before one specific technique is selected over another. In this regard, the location or ‘height’ of the osteotomy relative to the apex of deformity has an inherent effect on overall limb alignment, as an osteotomy done too far away from the apex of deformity will result in translation of the proximal and distal axes of the osteotomised bone. This can result in secondary deformities that may influence healing of the osteotomy and longevity of the adjacent joints and might be cosmetically unacceptable. To understand the overall effect of osteotomy location on limb alignment, the osteotomy rules should be reviewed [73]. These rules are: • Osteotomy rule 1: If the osteotomy passes through the apex of deformity and the axis of correction passes through a point on the transverse bisector line, realignment occurs without translation. • Osteotomy rule 2: If the osteotomy passes through a different level than the apex of deformity but the axis of correction passes through a point on the transverse bisector line, realignment will occur with translation at the osteotomy level. • Osteotomy rule 3: If the osteotomy passes through a different level than the apex of deformity and the axis of correction does not pass through a point on the transverse bisector line, realignment will result in translation of the proximal and distal bone axes [73].

N. Ferreira

In general, osteotomies are broadly grouped into those used for acute corrections and those used for gradual correction, although some overlap exists [74]. The most common examples are simple osteotomies followed by either closing wedge or opening wedge corrections. Closing wedge osteotomies, like the one described by Coventry, has the advantage of bony contact and immediate stability, especially when combined with rigid internal fixation [75]. The major disadvantage of  these osteotomies is the loss of limb length and potential limb length discrepancy as a result. Opening wedge osteotomies, as commonly used for the high tibial osteotomies, has the advantage of maintaining limb length but results in loss of bone contact and potential instability that may give rise to poor bone healing when used for acute corrections. Dome osteotomies aim to improve bone contact while avoiding loss of limb length. The original Maquet Dome osteotomy is done away from the apex of the limb deformity with resultant translation of the segmental axes of the osteotomised bone and an osteotomy rule 3 correction [76]. The focal dome osteotomy, as described by Paley, uses the apex of deformity as the axis of the dome cut and alignment of segmental axes after correction and an osteotomy rule 2 correction [77]. The oblique osteotomy as described by Rab, uses an osteotomy in an oblique plane to correct a deformity in the coronal, sagittal and axial planes [78]. Although the Ilizarov corticotomy, De Bastiani osteotomy and Afghan technique Gigli saw osteotomy can be used for both acute and gradual corrections, these techniques are generally employed for distraction osteogenesis and gradual correction of deformities [79–82] (Fig. 19.4). Despite theoretical advantages of one technique over another, multiple studies have failed to show any clinical difference in regenerate formation [83, 84]. Regardless of your chosen osteotomy technique, the general principle of performing a low-­ energy osteotomy to preserve local biology should be adhered to.

19  Non-infected Nonunions and Malunions Around the Knee

191

Fig. 19.4  Intra-operative images of a proximal femur De Bastiani osteotomy. The sequence of images showing initial drill holes followed by osteotomy completion with a sharp osteotome and the resultant transverse osteotomy Fig. 19.5 Radiographs of a patient with a proximal tibia malunion. The sequence of images showing initial deformity followed by gradual correction with a hexapod circular external fixator. The final image shows the final result following correction and removal of the external fixator

19.3.4 Correction and Fixation The site, magnitude and direction of deformity play an important role in deciding between acute and gradual deformity correction. Despite the effect of the chosen osteotomy and correction method of limb length, the overall effect of correction on surrounding soft tissue structures should also be considered. The common peroneal nerve, for example, is at risk during the correction of large angular and/ or rotational deformities about the knee. In these

scenarios it might be wise to consider gradual correction to allow monitoring of nerve function throughout the correction process. Fixation options are generally divided into internal and external fixation methods. Internal fixation methods are mostly used for fixation following acute deformity correction, whereas external fixation methods, and in particular hexapod circular external fixators, are mostly used for gradual correction of deformities (Fig. 19.5). Recent advances in deformity correction techniques have blurred the lines between which fixa-

N. Ferreira

192

cases, internal fixation can be in the form of either intramedullary nails or plate and screws. Another example is in the case where relatively small metaphyseal angular deformities are associated with significant limb length discrepancy. In these cases, acute correction of angular deformities and subsequent gradual lengthening with the use of a lengthening intramedullary nail can be considered (Fig.  19.6). Clinical case illustrating three different correction methods: acute correction and plate fixation of a distal femur deformity combined with proximal femur intramedullay lengthning. Gradual hexapod external fixator correction of an ipsilateral proximal tibial deformity. A special technique, described by Baumgart, for femoral deformity correction takes the effect of lengthening along the anatomical axis of the femur into account, and any surgeon undertaking this strategy should be aware of this [23] (Fig. 19.7). Advances in fixation technology have expanded our ability to correct limb deformities more accurately and with fewer complications. Fig. 19.6  Radiograph of a patient with gradual lengthening utilizing a lengthening intramedullary nail

tion methods are used for which correction strategies. Traditionally internal fixation was reserved for acute correction strategies, while external fixation was primarily used for gradual correction strategies [20–22, 85–88]. This was due to the static nature of most internal fixation devices and the ability of external fixators to affect incremental corrections over time. The drawback of acute correction and immediate internal fixation was the lack of accuracy that the gradual methods provided, while external fixation was associated with patient discomfort and pin site complications [89, 90]. Techniques that take advantage of the accuracy of gradual correction with the comfort of internal fixation are becoming more widespread. These include the use of hexapod circular external fixators for acute on-table corrections followed by immediate internal fixation with a technique termed computer hexapod-assisted orthopaedic surgery (CHAOS) [91–96]. In these

19.4 Case Example A 42-year-old woman presented to us complaining of a deformed left lower limb and resultant limping (Case courtesy of Dr Gian du Preez). She provided the history of being involved in a motor vehicle collision in North Africa years earlier where she sustained bilateral open femur fractures and a closed left proximal tibia fracture. The injuries were managed by surgical debridement and traction. Although there was a history of previous infection of the left femur fracture, at time of presentation she had healed soft tissues with extensive scarring of the lateral distal thigh but had no clinical, radiological or biochemical signs of acute or chronic infection. Physical examination revealed normal hip, ankle and subtalar joint alignment and motion and near-normal knee range of motion of the left knee. Radiographic evaluation confirmed bilateral femur and left tibia malunions.

19  Non-infected Nonunions and Malunions Around the Knee

Fig. 19.7  Radiographs of a patient with a distal femur malunion and leg length discrepancy. The sequence of images showing initial deformity followed by an osteotomy with acute correction and intramedullary lengthening

193

nail to address limb length discrepancy. The final image shows the final result following correction of limb length and exchange to a regular interlocking nail

The left femur had a valgus malunion of a segmental distal meta-diaphyseal fracture. The middle segment was healed proximally and distally but was translated medially so that the medullary canal of the proximal and middle segments was no longer aligned. The mLDFA measured 70°. On the sagittal plane, there was an 11° procurvatum deformity and no rotational component on the axial plane. The left tibia showed a varus malunion of the proximal metaphysis with the MPTA measuring 74°. There was no sagittal plane or axial plane deformities. The right femur had a 14° varus and 5° recurvatum deformity at the previous diaphyseal fracture. No axial plane deformity was present. There was an overall 25 mm limb length discrepancy with the left limb being shorter than the right. The decision was taken to perform an acute opening wedge osteotomy and plating of left proximal tibial deformity and gradual opening wedge deformity correction with a hexapod external fixator for left femur malunion. The two opening wedge osteotomies combined to provide 15 mm of overall lengthening to the left lower limb.

194

During initial planning we decided to address the left femur and left tibia malunions first and then to reevaluate overall function. The option of an acute closing wedge osteotomy for the right femur malunion was discussed with the patient. At final review both osteotomies were united, and the lower limb mechanical axis was restored to normal. Despite the left limb still being approximately 10 mm shorter than the contralateral side, the patient was satisfied with the outcome and decided to defer correction of the right femur malunion.

References 1. Milner SA, Davis TR, Muir KR, Greenwood DC, Doherty M. Long-term outcome after tibial shaft fracture: is malunion important? J Bone Joint Surg Am. 2002;84–A(6):971–80. PubMed PMID: 12063331. Epub 2002/06/14 2. Greenwood DC, Muir KR, Doherty M, Milner SA, Stevens M, Davis TR. Conservatively managed tibial shaft fractures in Nottingham, UK: are pain, osteoarthritis, and disability long-term complications? J Epidemiol Community Health. 1997;51(6):701–4. PubMed PMID: 9519136. Pubmed Central PMCID: PMC1060570. Epub 1998/03/31

N. Ferreira 3. Milner SA, Moran CG. The long-term complications of tibial shaft fractures. Curr Orthop. 2003;17:200–5. 4. Schottel PC, O’Connor DP, Brinker MR. Time trade-­ off as a measure of health-related quality of life: long bone nonunions have a devastating impact. J Bone Joint Surg Am. 2015;97(17):1406–10. PubMed PMID: 26333735. Epub 2015/09/04 5. Tornetta P, 3rd, Collins E.  Semiextended position of intramedullary nailing of the proximal tibia. Clin Orthop Relat Res. 1996;328:185–9. PubMed PMID: 8653954. Epub 1996/07/01. 6. Matthews DE, McGuire R, Freeland AE.  Anterior unicortical buttress plating in conjunction with an unreamed interlocking intramedullary nail for treatment of very proximal tibial diaphyseal fractures. Orthopedics. 1997;20(7):647–8. PubMed PMID: 9243676. Epub 1997/07/01 7. Krettek C, Miclau T, Schandelmaier P, Stephan C, Mohlmann U, Tscherne H. The mechanical effect of blocking screws (“Poller screws”) in stabilizing tibia fractures with short proximal or distal fragments after insertion of small-diameter intramedullary nails. J Orthop Trauma. 1999;13(8):550–3. PubMed PMID: 10714781. Epub 2000/03/14 8. Krettek C, Stephan C, Schandelmaier P, Richter M, Pape HC, Miclau T. The use of Poller screws as blocking screws in stabilising tibial fractures treated with small diameter intramedullary nails. J Bone Joint Surg Br. 1999;81(6):963–8. PubMed PMID: 10615966. Epub 2000/01/01 9. Bhandari M, Audige L, Ellis T, Hanson B, Evidence-­ Based Orthopaedic Trauma Working Group. Operative treatment of extra-articular proximal tibial fractures. J Orthop Trauma. 2003;17(8):591–5. PubMed PMID: 14504586. Epub 2003/09/25 10. Dunbar RP, Nork SE, Barei DP, Mills WJ. Provisional plating of type III open tibia fractures prior to intramedullary nailing. J Orthop Trauma. 2005;19(6):412– 4. PubMed PMID: 16003202. Epub 2005/07/09. eng 11. Nork SE, Barei DP, Schildhauer TA, Agel J, Holt SK, Schrick JL, et  al. Intramedullary nailing of proximal quarter tibial fractures. J Orthop Trauma. 2006;20(8):523–8. PubMed PMID: 16990722. Epub 2006/09/23 12. Eastman JG, Tseng SS, Lee MA, Yoo BJ.  The retropatellar portal as an alternative site for tibial nail insertion: a cadaveric study. J Orthop Trauma. 2010;24(11):659–64. PubMed PMID: 20926963. Epub 2010/10/12 13. Eastman J, Tseng S, Lo E, Li CS, Yoo B, Lee M. Retropatellar technique for intramedullary nailing of proximal tibia fractures: a cadaveric assessment. J Orthop Trauma. 2010;24(11):672–6. PubMed PMID: 20926965. Epub 2010/10/12 14. Gelbke MK, Coombs D, Powell S, DiPasquale TG.  Suprapatellar versus infra-patellar intramedullary nail insertion of the tibia: a cadaveric model for comparison of patellofemoral contact pressures and forces. J Orthop Trauma. 2010;24(11):665–71. PubMed PMID: 20926959. Epub 2010/10/12

19  Non-infected Nonunions and Malunions Around the Knee 15. Lowe JA, Tejwani N, Yoo B, Wolinsky P.  Surgical techniques for complex proximal tibial fractures. J Bone Joint Surg Am. 2011;93(16):1548–59. PubMed PMID: 22204013. Epub 2011/12/29 16. Ricci WM, O’Boyle M, Borrelli J, Bellabarba C, Sanders R. Fractures of the proximal third of the tibial shaft treated with intramedullary nails and blocking screws. J Orthop Trauma. 2001;15(4):264–70. PubMed PMID: 11371791. Epub 2001/05/24 17. Rozbruch SR, Helfet DL, Blyakher A. Distraction of hypertrophic non-union of tibia with deformity using Ilizarov / Taylor Spatial Frame: report of two cases. Arch Orthop Trauma Surg. 2002;122:295–198. 18. Feldman DS, Shin SS, Madan S, Koval KJ. Correction of tibial malunion and nonunion with six-axis analysis deformity correction using the Taylor spatial frame. J Orthop Trauma. 2003;17(8):549–54. 19. Rodl R, Leidinger B, Bohm A, Winkelmann W.  Correction of deformities with conventional and hexapod frames—comparison of methods. Zeitschrift fur Orthopadie und ihre Grenzgebiete. 2003;141(1):92–8. 20. Fadel M, Hosny G.  The Taylor spatial frame for deformity correction in the lower limbs. Int Orthop. 2005;29(2):125–9. PubMed PMID: 15703937. Pubmed Central PMCID: 3474509 21. Rozbruch SR, Fragomen AT, Ilizarov S. Correction of tibial deformity with use of the Ilizarov-Taylor spatial frame. J Bone Joint Surg Am. 2006;88-A(Suppl 4):156–74. 22. Manner HM, Huebl M, Radler C, Ganger R, Petje G, Grill F.  Accuracy of complex lower-limb deformity correction with external fixation: a comparison of the Taylor Spatial Frame with the Ilizarov ring fixator. J Child Orthop. 2007;1(1):55–61. PubMed PMID: 19308507. Pubmed Central PMCID: 2656701. Epub 2007/03/01 23. Baumgart R. The reverse planning method for lengthening of the lower limb using a straight intramedullary nail with or without deformity correction. A new method. Oper Orthop Traumatol. 2009;21(2):221–33. PubMed PMID: 19685230. Epub 2009/08/18 24. Ferreira N, Marais LC, Aldous C. Hexapod external fixator closed distraction in the management of stiff hypertrophic tibial nonunions. Bone Joint J. 2015;97-­ B(10):1417–22. PubMed PMID: 26430019. Epub 2015/10/03 25. Ferreira N, Marais LC. Distraction and deformity correction of stiff tibia nonunions with hexapod external fixation. JBJS EST. 2016;6(4):e36(1–7). 26. Ferreira N, Marais LC.  Femoral locking plate failure salvaged with hexapod circular external fixation: a report of two cases. Strategies Trauma Limb Reconstr. 2016;11(2):123–7. PubMed PMID: 27234444. Pubmed Central PMCID: PMC4960056. Epub 2016/05/29 27. Mahomed N, O’Farrel P, Barnard A, Birkholtz FF.  Monofocal distraction treatment of stiff aseptic tibial nonunions with hexapod external fixation. J Limb Lengthen Reconstr. 2017;3(2):101–6.

195

28. Cierny G 3rd, Mader JT, Penninck JJ. A clinical staging system for adult osteomyelitis. Clin Orthop Relat Res. 2003;414:7–24. PubMed PMID: 12966271 29. Cierny G, 3rd. Surgical treatment of osteomy elitis. Plast Reconstr Surg. 2011;127 Suppl 1:190S–204S.  PubMed PMID: 21200291. Epub 2011/01/14. 30. Marais LC, Ferreira N, Aldous C, Le Roux TLB. The classification of chronic osteomyelitis. SA Orthop J. 2014;13(1):22–8. 31. Marais LC, Ferreira N, Aldous C, Le Roux TLB. The management of chronic osteomyelitis. Part I Diagnostic work-up and surgical principles. SA Orthop J. 2014;13(2):42–8. 32. Marais LC, Ferreira N, Aldous C, Le Roux TLB. The management of chronic osteomyelitis: Part II— Principles of post-infective reconstruction and antibiotic therapy. SA Orthop J. 2014;13(3):32–9. 33. Varecka TF, Wiesner LL.  The influence of acute haemorrhagic anemia on fracture healing. Orthop Today. 2012; Jan 15–18. Wailea, Hawaii. 34. Urabe K, Hotokebuchi T, Oles KJ, Bronk JT, Jingushi S, Iwamoto Y, et al. Inhibition of endochondral ossification during fracture repair in experimental hypothyroid rats. J Orthop Res. 1999;17(6):920–5. PubMed PMID: 10632459 35. Brinker MR, O’Connor DP, Monla YT, Earthman TP. Metabolic and endocrine abnormalities in patients with nonunions. J Orthop Trauma. 2007;21(8):557– 70. PubMed PMID: 17805023 36. Gaston MS, Simpson AH. Inhibition of fracture healing. J Bone Joint Surg Br. 2007;89(12):1553–60. PubMed PMID: 18057352 37. Aird J, Noor S, Rollinson P.  Is fracture healing affected by HIV in open fractures? J Bone Joint Surg Br. 2012;94-B(SUPP XIX):16. 38. Gardner RO, Bates JH, Ng’oma E, Harrison WJ. Fracture union following internal fixation in the HIV population. Injury. 2013;44(6):830–3. PubMed PMID: 23267724 39. Kyro A, Usenius JP, Aarnio M, Kunnamo I, Avikainen V.  Are smokers a risk group for delayed healing of tibial shaft fractures? Annales chirurgiae et gynaecologiae. 1993;82(4):254–62. PubMed PMID: 8122874 40. Cobb TK, Gabrielsen TA, Campbell DC 2nd, Wallrichs SL, Ilstrup DM.  Cigarette smoking and nonunion after ankle arthrodesis. Foot Ankle Int. 1994;15(2):64–7. PubMed PMID: 7981802 41. Harvey EJ, Agel J, Selznick HS, Chapman JR, Henley MB. Deleterious effect of smoking on healing of open tibia-shaft fractures. Am J Orthop. 2002;31(9):518– 21. PubMed PMID: 12650537 42. Chakkalakal DA.  Alcohol-induced bone loss and deficient bone repair. Alcohol Clin Exp Res. 2005;29(12):2077–90. PubMed PMID: 16385177 43. Chakkalakal DA, Novak JR, Fritz ED, Mollner TJ, McVicker DL, Garvin KL, et  al. Inhibition of bone repair in a rat model for chronic and excessive alcohol consumption. Alcohol. 2005;36(3):201–14. PubMed PMID: 16377462

196 44. Askew A, Chakkalakal D, Fang X, McGuire M.  Delayed fracture healing in alcohol abusers— a preliminary retrospective study. Open Bone J. 2011;3:1–5. 45. Chen Y, Guo Q, Pan X, Qin L, Zhang P. Smoking and impaired bone healing: will activation of cholinergic anti-inflammatory pathway be the bridge? Int Orthop. 2011;35(9):1267–70. PubMed PMID: 21409368. Pubmed Central PMCID: 3167453 46. Hernigou J, Schuind F.  Smoking as a predictor of negative outcome in diaphyseal fracture healing. Int Orthop. 2013;37(5):883–7. PubMed PMID: 23392346. Pubmed Central PMCID: 3631490 47. Schenker ML, Scolaro JA, Yannascoli SM, Baldwin KD, Mehta S, Ahn J. Blowing smoke: A meta-analysis of the effects of smoking on fracture healing and postoperative infection. Univ Pa Orthop J. 2013;23:62–3. 48. Eschle D, Aeschlimann AG.  Is supplementation of vitamin d beneficial for fracture healing? A short review of the literature. Geriatr Orthop Surg Rehabil. 2011;2(3):90–3. PubMed PMID: 23569676. Pubmed Central PMCID: PMC3597312. Epub 2011/05/01 49. Pourfeizi HH, Tabriz A, Elmi A, Aslani H. Prevalence of vitamin D deficiency and secondary hyperparathyroidism in nonunion of traumatic fractures. Acta Med Iran. 2013;51(10):705–10. PubMed PMID: 24338144. Epub 2013/12/18 50. Gorter EA, Hamdy NA, Appelman-Dijkstra NM, Schipper IB. The role of vitamin D in human fracture healing: a systematic review of the literature. Bone. 2014;64:288–97. PubMed PMID: 24792958. Epub 2014/05/06 51. Childs BR, Andres BA, Vallier HA.  Economic benefit of calcium and vitamin D supplementation: does it outweigh the cost of nonunions? J Orthop Trauma. 2016;30(8):e285–8. PubMed PMID: 27010185. Epub 2016/03/25 52. Gorter EA, Krijnen P, Schipper IB. Vitamin D status and adult fracture healing. J Clin Orthop Trauma. 2017;8(1):34–7. PubMed PMID: 28360494. Pubmed Central PMCID: PMC5359504. Epub 2017/04/01 53. Pountos I, Georgouli T, Blokhuis TJ, Pape HC, Giannoudis PV.  Pharmacological agents and impairment of fracture healing: what is the evidence? Injury. 2008;39(4):384–94. PubMed PMID: 18316083 54. Pountos I, Georgouli T, Bird H, Kontakis G, Giannoudis PV.  The effect of antibiotics on bone healing: current evidence. Expert Opin Drug Saf. 2011;10(6):935–45. PubMed PMID: 21824037 55. Pountos I, Giannoudis PV, Jones E, English A, Churchman S, Field S, et al. NSAIDS inhibit in vitro MSC chondrogenesis but not osteogenesis: implications for mechanism of bone formation inhibition in man. J Cell Mol Med. 2011;15(3):525–34. PubMed PMID: 20070439 56. Pountos I, Georgouli T, Calori GM, Giannoudis PV. Do nonsteroidal anti-inflammatory drugs affect bone healing? A critical analysis. TheScientificWorldJournal. 2012;2012:606404. PubMed PMID: 22272177. Pubmed Central PMCID: 3259713

N. Ferreira 57. Judet J, Judet R. L’osteogene et les retards de consolidation et les pseudarthroses des os longs. Huitieme Congress SICOT1960. p. 15. 58. Weber B, Cech O, editors. Pseudarthrosis. Bern, Switzerland: Hans Huber; 1976. 59. Catagni M, editor. Treatment of fractures, non-unions, and bone loss of the tibia with the Ilizarov method; 1998. 60. Paley D, Catagni MA, Argnani F, Villa A, Benedetti GB, Cattaneo R. Ilizarov treatment of tibial nonunions with bone loss. Clin Orthop Relat Res. 1989;241:146– 65. PubMed PMID: 2924458 61. Paley D.  Treatment of tibial nonunion and bone loss with the Ilizarov technique. Instr Course Lect. 1990;39:185–97. PubMed PMID: 2186101. Epub 1990/01/01 62. Wu CC, Chen WJ. A revised protocol for more clearly classifying a nonunion. J Orthop Surg. 2000;8(1):45– 52. PubMed PMID: 12468875 63. Calori GM, Phillips M, Jeetle S, Tagliabue L, Giannoudis PV. Classification of non-union: need for a new scoring system? Injury. 2008;39(Suppl 2):S59– 63. PubMed PMID: 18804575 64. Abumunaser LA, Al-Sayyad MJ.  Evaluation of the calori et Al nonunion scoring system in a retrospective case series. Orthopedics. 2011;34(5):359. PubMed PMID: 21598896 65. Ferreira N, Marais LC.  Management of tibial non-­ unions according to a novel treatment algorithm. Injury. 2015;46(12):2422–7. PubMed PMID: 26492881. Epub 2015/10/24 66. Ferreira N, Marais LC, Aldous C. Mechanobiology in the management of mobile atrophic and oligotrophic tibial nonunions. J Orthop. 2015;12(Suppl 2):S182–7. PubMed PMID: 27047221. Pubmed Central PMCID: 4796579 67. Ferreira N, Marais LC, Aldous C.  Management of tibial non-unions: Prospective evaluation of a comprehensive treatment algorithm. SA Orthop J. 2016;15(1):60–6. 68. Catagni MA, Guerreschi F, Holman JA, Cattaneo R.  Distraction osteogenesis in the treatment of stiff hypertrophic nonunions using the Ilizarov apparatus. Clin Orthop Relat Res. 1994;301:159–63. PubMed PMID: 8156667 69. Saleh M, Royston S.  Management of nonunion of fractures by distraction with correction of angulation and shortening. J Bone Joint Surg [Br]. 1996;78-B:105–9. 70. Kanellopoulos AD, Soucacos PN.  Management of nonunion with distraction osteogenesis. Injury. 2006;37(Suppl 1):S51–5. PubMed PMID: 16574120 71. El-Rosasy M.  Distraction histogenesis for hypertrophic nonunion of the tibia with deformity and shortening. Eur J Orthop Surg Traumatol. 2008;18(2):119–25. 72. Ferreira N, Birkholtz FF, Marais LC. Tibial non-union treated with the TL-Hex: a case report. SA Orthop J. 2015;14(1):44–7. 73. Paley D, Herzenberg JE, Tetsworth K, McKie J, Bhave A.  Deformity planning for frontal and sagit-

19  Non-infected Nonunions and Malunions Around the Knee tal plane corrective osteotomies. Orthop Clin N Am. 1994;25(3):425–65. PubMed PMID: 8028886. Epub 1994/07/01 74. Dabis J, Templeton-Ward O, Lacey AE, Narayan B, Trompeter A.  The history, evolution and basic science of osteotomy techniques. Strat Trauma Limb Reconstr. 2017;12(3):169–80. PubMed PMID: 28986774. Pubmed Central PMCID: PMC5653603. Epub 2017/10/08 75. Coventry MB. Osteotomy of the upper portion of the tibia for degenerative arthritis of the knee. A preliminary report. J Bone Joint Surg Am. 1965;47:984–90. PubMed PMID: 14318636. Epub 1965/07/01 76. Maquet P.  Valgus osteotomy for osteoarthritis of the knee. Clin Orthop Relat Res. 1976;120:143–8. PubMed PMID: 975649. Epub 1976/01/01 77. Paley D, Maar DC, Herzenberg JE. New concepts in high tibial osteotomy for medial compartment osteoarthritis. Orthop Clin N Am. 1994;25(3):483–98. PubMed PMID: 8028889. Epub 1994/07/01 78. Rab GT.  Oblique tibial osteotomy revisited. J Child Orthop. 2010;4(2):169–72. PubMed PMID: 20234769. Pubmed Central PMCID: PMC2832880. Epub 2010/03/18 79. De Bastiani G, Aldegheri R, Renzi-Brivio L, Trivella G. Limb lengthening by callus distraction (callotasis). J Pediatr Orthop. 1987;7(2):129–34. PubMed PMID: 3558791 80. Paley D.  The Ilizarov corticotomy. Tech Orthop. 1990;5(4):41–52. https://journals. l w w. c o m / t e c h o r t h o / F u l l t e x t / 1 9 9 0 / 1 2 0 0 0 / The_Ilizarov_corticotomy.8.aspx 81. Paley D, Tetsworth K.  Percutaneous osteotomies. Osteotome and Gigli saw techniques. Orthop Clin N Am. 1991;22(4):613–24. PubMed PMID: 1945339. Epub 1991/10/01 82. Paktiss AS, Gross RH.  Afghan percutaneous osteotomy. J Pediatr Orthop. 1993;13(4):531–3. PubMed PMID: 8370790. Epub 1993/07/01 83. Frierson M, Ibrahim K, Boles M, Bote H, Ganey T. Distraction osteogenesis. A comparison of corticotomy techniques. Clin Orthop Relat Res. 1994;301:19– 24. PubMed PMID: 8156672 84. Elmadag M, Uzer G, Yildiz F, Erden T, Bilsel K, Buyukpinarbasili N, et  al. Comparison of four different techniques for performing an osteotomy: a biomechanical, radiological and histological study on rabbits tibias. Bone Joint J. 2015;97-B(12):1628–33. PubMed PMID: 26637676. Epub 2015/12/08 85. Binski J. Taylor spatial frame in acute fracture care. Tech Orthop. 2002;17:173–84.

197

86. Al-Sayyad MJ. Taylor spatial frame in the treatment of pediatric and adolescent tibial shaft fractures. J Pediatr Orthop. 2006;26(2):164–70. PubMed PMID: 16557128. Epub 2006/03/25.eng 87. Eidelman M, Bialik V, Katzman A.  Correction of deformities in children using the Taylor spatial frame. J Pediatr Orthop B. 2006;15:387–95. 88. Rozbruch SR, Segal K, Ilizarov S, Fragomen AT, Ilizarov G. Does the Taylor spatial frame accurately correct tibial deformities? Clin Orthop Relat Res. 2009;468:1352–61. 89. Paley D.  Problems, obstacles, and complications of limb lengthening by the Ilizarov technique. Clin Orthop Relat Res. 1990;250:81–104. PubMed PMID: 2403498 90. Antoci V, Ono CM, Antoci V Jr, Raney EM. Pin-­tract infection during limb lengthening using external fixation. Am J Orthop. 2008;37(9):E150–4. PubMed PMID: 18982187 91. Seide K, Faschingbauer M, Wenzl ME, Weinrich N, Juergens C. A hexapod robot external fixator for computer assisted fracture reduction and deformity correction. Int J Med Robot. 2004;1(1):64–9. PubMed PMID: 17520597. Epub 2007/05/24 92. Rogers MJ, McFadyen I, Livingstone JA, Monsell F, Jackson M, Atkins RM.  Computer hexapod assisted orthopaedic surgery (CHAOS) in the correction of long bone fracture and deformity. J Orthop Trauma. 2007;21(5):337–42. PubMed PMID: 17485999. Epub 2007/05/09 93. Tang P, Hu L, Du H, Gong M, Zhang L.  Novel 3D hexapod computer-assisted orthopaedic surgery system for closed diaphyseal fracture reduction. Int J Med Robot. 2012;8(1):17–24. PubMed PMID: 22081502. Epub 2011/11/15 94. Du H, Hu L, Li C, Wang T, Zhao L, Li Y, et  al. Advancing computer-assisted orthopaedic surgery using a hexapod device for closed diaphyseal fracture reduction. Int J Med Robot. 2015;11(3):348–59. PubMed PMID: 25242630. Epub 2014/09/23 95. Hughes A, Parry M, Heidari N, Jackson M, Atkins R, Monsell F.  Computer hexapod-assisted orthopaedic surgery for the correction of tibial deformities. J Orthop Trauma. 2016;30(7):e256–61. PubMed PMID: 27206256. Epub 2016/05/21 96. Hughes A, Heidari N, Mitchell S, Livingstone J, Jackson M, Atkins R, et  al. Computer hexapod-­ assisted orthopaedic surgery provides a predictable and safe method of femoral deformity correction. Bone Joint J. 2017;99-B(2):283–8. PubMed PMID: 28148674. Epub 2017/02/06

Posttraumatic Bone Defects Around the Knee

20

Martijn van Griensven

20.1 Introduction Bone tissue has a good possibility for natural healing. Direct healing of a cortical bone defect will occur spontaneously when the defect is smaller than 2 mm. Moreover, this only happens when absolute stability is present [1]. When larger defects are present, healing is more complicated. 5–10% of all fractures and 20% of fractures after high-energy trauma develop delayed union or non-union [2]. In the case of delayed union or non-union, the regeneration capacity of the body is insufficient. In that case, additional surgical interventions to fill the bone gaps are needed besides the surgical stabilization procedures. To fill up those bone defects, autologous or allogeneic bone as well as synthetic biomaterials can be used. Growth factors and other stimulating factors that are naturally involved in the healing process can be added to the filling material. Therefore, requirements for bone healing are [3, 4]: • • • •

Cells with osteogenic potential Osteoconductive scaffold Osteoinductive stimulus A mechanically stable environment

M. van Griensven (*) cBITE, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, The Netherlands e-mail: [email protected]

These requirements can be summarized as “diamond concept” [3–5]. This is a very important concept. Approximately 4,000,000 operations using bone grafts or synthetic biomaterials are performed worldwide [2]. Which graft material is used depends on many different factors, e.g., defect size, biomechanical characteristics, bioactivity, resorption rate, etc. [2].

20.2 Bone Grafts 20.2.1 Autologous Bone Grafts Autologous bone grafts are still the gold standard for bone replacement therapy. The osteogenic characteristics are associated with the presence of osteogenic precursors and osteoblasts in the graft material. The autologous bone graft needs to be harvested using the correct techniques to avoid damaging the graft. If performed incorrectly, osteonecrosis at the implantation side can occur, and the graft becomes useless. As an autologous bone graft is immediately implanted after harvesting, all cells present will survive, and all growth factors will remain active. Indeed, it could be shown that autologous bone grafts contain several osteogenic stimulating growth factors [6], such as bone morphogenetic protein-2 and bone morphogenetic protein-4, fibroblast growth factor, vascular endothelial growth factor, platelet-derived growth

© Springer Nature Switzerland AG 2021 M. Hanschen et al. (eds.), Knee Fractures, Strategies in Fracture Treatments, https://doi.org/10.1007/978-3-030-81776-3_20

199

200

factor, and insulin-like growth factor-I, among others. The osteoconductive characteristics of the graft are also dependent on the 3D structure, which is important for the speed of bone integration [7]. Therefore, bone grafts from spongious bone incorporate much faster due to their porous structure than cortical grafts [8]. A special entity in the field of autologous bone grafts is the grafting material obtained from a procedure called “Reamer Irrigator Aspirator” (RIA). This system was originally developed to reduced complications of reaming of long bones for fractures such as pulmonary fat embolism. Furthermore, due to the continuous rinsing and suctioning of the viscous bone marrow contents, the normally present increase in marrow pressure due to the reaming is diminished [9, 10]. Moreover, thermal damage of the bone tissue is prevented by the rinsing and by using sharp drill heads designated for one-time use [11]. While using the Reamer Irrigator Aspirator system to diminish complications of reaming, it was noted that the suction material contains bone marrow including mesenchymal stem cells and growth factors as well as bone dust from the reamed cortex. Reimplantation of this material accelerated bone formation in an ovine model [12]. Instead of discarding this material, it can also be collected using a filter system. In this filter system, during reaming of a complete femur using this Reamer Irrigator Aspirator system, a volume of this composite mixture of about 25–90 cm3 can be harvested [13]. It can be used to fill bone defects or bone gaps after osteotomy [14]. It has also been used to be administered to large segmental bone defects in the second stage of the Masquelet procedure [15]. This composite material has osteoinductive, osteoconductive, and osteogenic characteristics [16]. The osteogenic entity in this material is derived from the presence of many mesenchymal stem cells [6, 17]. As a matter of fact, these mesenchymal stem cells from the Reamer Irrigator Aspirator material show a higher capacity in the expression of factors for inducing vessels, skeletal tissues, and hematopoietic inductors [3, 18– 20]. Besides those stem cells, growth factors are present in the Reamer Irrigator Aspirator material

M. van Griensven

in similar concentrations to autografts [6, 17, 21–23]. A comparison in a meta-analysis of the Reamer Irrigator Aspirator procedure versus autograft harvesting showed less complications for the Reamer Irrigator Aspirator compared to iliac crest autograft harvesting [24, 25]. A major complication of the Reamer Irrigator Aspirator procedure is a femur fracture of the femur that was previously intact [26]. The risk for a femur fracture can be reduced when using a preoperative planning concerning the diameter of the bone marrow canal and the thickness of the cortex in association with the diameter of the drill head [27]. Another risk is blood loss from endosteal vessels [28, 29]. Nevertheless, the coagulation system is hardly compromised by Reamer Irrigator Aspirator [30]. From the abovementioned characteristics, it is clear that autologous bone grafts are a powerful means to fill bone defects. However, autologous bone for grafting is not an unlimited source in the body. The iliac crest and the femoral intramedullary canal are abundant sources, but still limited. For large bone defects, mostly more bone graft material is needed than can be harvested. Moreover, harvesting autologous bone grafts is associated with comorbidities such as pain, an increased infection risk, and the risk of fracture of the harvesting site [7, 31]. Thus, the surgeon needs to consider also other graft materials for use in posttraumatic bone defects around the knee.

20.2.2 Allogeneic Bone Grafts Allogeneic bone grafts are obtained from corpses or from patients undergoing total joint endoprosthesis procedures. Allogeneic bone grafts need to be processed after harvesting. This is important to remove living cellular components in order to inhibit graft rejection. This is a disadvantage as by removing the living cells from the graft material, the osteogenic entity of the graft is removed. A commercially available allogeneic bone graft is demineralized bone matrix. Demineralized bone matrix exists in different constitutions such

20  Posttraumatic Bone Defects Around the Knee

as spongious chips, gels, putty, or cement. The problem with the demineralized bone matrix is batch-to-batch variability concerning growth factor content. The concentrations of bone morphogenetic protein-2 ranged from 22 to 110  pg/mg when comparing different lots [32]. A similar variability was determined for bone morphogenetic protein-7 concentrations. Besides demineralized bone matrix, decellularized allografts are used. They can be massive and even customized according to computer tomography imaging [33, 34]. Vascularization of large allografts is problematic. This can be facilitated using covering with an osteocutaneous flap [35]. A general problem of allogeneic bone grafts is also the risk of disease transmission and possible immunologic reactions. The risk for transmission of viral pathogens is 1:1,500,000 for human immunodeficiency virus, 1:60,000 for hepatitis C, and 1:100,000 for hepatitis B [36]. Allografts have been used for reconstructing large distal femur or proximal tibia defects due to tumor resection, trauma, or revision arthroplasty. Allografts used to fill defects during revision arthroplasty show that they provide stability and support with good bone regeneration [37–39]. The grafts showed a good union to host bone in histology [38]. However, infection may occur and leads to a loss of the allograft and thereby the failure of bone regeneration [38, 39]. In very few cases, allograft fracture can occur [39]. In 113 cases of remaining bone defects after tumor resection, allografts were used to fill the defects. In 7.8% of the patients, an infection was observed as complication. However, due to the concomitant chemotherapy and/or radiotherapy, this could be expected. In six patients, a fracture of the allograft occurred. The authors concluded that the use of structured allograft to reconstruct the bone defects after massive tumor resection is a feasible treatment [40]. In the setting of trauma, allografts have been used in large critical defects or in non-union defects. In 22 patients with non-unions of the distal femur, cortical allograft struts were used. All patients showed a complete union of the defect in the mean period of 6.2 months. No complications

201

were observed, and the motion outcome of the knee was very good [41]. In the acute setting, allograft implantation can be used for the management of large segmental bone defects. A 9-cm-long bone defect in the left femur due to an open fracture was treated with an allograft and additional bone marrow. After 3 months, callus bridging was observed, and after 6 months the fracture was united [42]. In three patients with open tibia fractures with associated extensive segmental bone loss, cancellous allograft was used to fill a cylindrical titanium mesh cage. The allograft was partially combined with demineralized bone matrix. After 1 year, all patients showed a united defect with bony growth throughout the cages [43].

20.2.3 Xenografts Xenografts are bone grafts derived from other species than human. In practice that mainly means the use of bovine bone grafts. They can be either obtained as sintered material in granules or in processed blocks or chips. This material of bovine origin is mainly used in the area of maxillofacial surgery for filling alveolar cavities, alveolar ridge augmentation, and mandibular augmentation. Using lyophilized bovine bone xenograft granules in the alveolar bone after tooth extraction showed no significant changes of bone resorption for the xenografts, whereas non-­ filled defects showed bone resorption [44]. A histomorphometric analysis showed that a highly purified bovine xenograft used in mandibular horizontal ridge augmentation induced a bone core and new bone formation [45]. Also intra-­ bony defects occurring due to peri-implantitis regenerated better with bovine xenografts than autologous bone graft [46]. Bovine bony xenografts are also used for bone defects in the trauma and orthopedic arena. In 1995, such an implant was used for intervertebral body spondylodesis. Although the material itself had excellent biomechanical properties, the clinical performance was poor showing collapses and lysis of the xenografts in patients [47]. In a large study with 232 patients, allogeneic cancellous

202

bone grafts were compared to bovine xenograft. It was shown that no differences could be observed between both groups. Similar bone structures could be observed in the histological examination. All biomaterials either allogeneic or xenogeneic were biocompatible in an in vitro testing system. The authors concluded that there was no difference between the materials for the use in the treatment of skeletal defects [48]. Bovine xenografts were also used in acetabular bone defects, and it was shown that new bone formation occurred in 85.7% of the patients. The new bone area was almost two thirds of the total bone matrix area. Xenograft absorption was seen in 12 out of 14 patients. The xenograft implantation was shown to be safe as no inflammatory responses were observed and new bone formation occurred [49]. In the area of the pelvis, bovine cancellous xenografts were used to fill the iliac crest defects after harvesting tricortical autografts. Fusion of the iliac crest was obtained in 94% of patients within 4 months. Integration of the xenografts occurred also in 94% of the patients within 3 months. No major complications or immunologic reactions occurred [50]. Using bovine xenografts in open wedge osteotomies showed in 47% of the patients incorporated avital graft remnants. New bone formation was observed in 53% of the patients. Radiologic signs of osteointegration and incomplete resorption could be observed. It was concluded that the bovine xenografts had excellent biocompatibility and good osteoconductive characteristics [51]. Bovine xenografts were used in 20 patients with bone defects in the tibia. The average healing time with the bovine xenografts was 4.8 months. Again, no immunologic reactions were observed, and the results were satisfactorily [52]. Using sintered bovine xenografts in the treatment of patellar, femoral, and tibial fractures resulted in union and increased bone mass in the defect areas [53]. Thus, it can be concluded that bovine xenografts seem to be safe as no immunologic reactions have been observed in none of the studies. Furthermore, new bone formation is observed although the resorption of the bovine xenografts

M. van Griensven

takes a long time similarly to synthetic hydroxyapatite grafts (see Sect. 20.2.4).

20.2.4 Synthetic Bone Grafts The advantage of synthetic bone grafts is that they can be produced and immediately thereafter shipped. Autologous bone grafts need to be harvested directly in the operating theater, and thereby the operation time and risks are increased. Allogeneic bone grafts need to be sent to a special facility, where the graft material is processed, checked, and then sent back to the surgeons. Synthetic bone graft material can be obtained as chips, granulate, putty, or as a paste. Some of the synthetic bone graft materials are also injectable. This is an advantage especially also in bone defects around the knee, as they can be administered minimally invasive. Furthermore, injectable synthetic bone grafts perfectly fit into the defect irrespective of the irregularity of the bone defect. Synthetic bone grafts can be produced using a large variety of different biomaterials. Also, the production can be performed using many different techniques, such as salt leaching, sintering, electro-spinning, mold extrusion, 3D printing, etc. The most used biomaterials for filling bone defects are hydroxyapatite and tricalcium phosphate. Seventy percent of the dry weight of natural bone consists of hydroxyapatite [2]. Synthetic hydroxyapatite shows a very long resorption time. It can be observed sometimes even years after implantation and therefore can lead to problems at the implantation site [54]. Concerning resorption time, tricalcium phosphate shows an advantage as it is faster resorbed than hydroxyapatite [55, 56]. Tricalcium phosphate in its beta crystalline structure has been successfully used in vertebra fusions and dental procedures [57, 58]. It has also been used in defects around the knee joint for tibia plateau fractures [55, 59, 60], large bone defects after tumor removal [61], and after high tibial osteotomies [62–64]. In order to improve the synthetic bone graft of hydroxyapatite and tricalcium phosphate, mixtures of the two of them have been developed. Those mixtures have, depending on the ratio,

20  Posttraumatic Bone Defects Around the Knee

good biomechanical characteristics from the hydroxyapatite and the optimal resorption rates from the β-tricalcium phosphate. These combinations are indeed frequently used by surgeons in the areas of spinal [65], dental [66], and hip operations [67]. Hydroxyapatite can also be mixed with calcium sulfate [68]. This can be made as an injectable bone graft. Calcium sulfate degrades fast, thereby leaving artificial “pores” in the hydroxyapatite. This allows for bone regeneration. Currently, a randomized, multicenter clinical trial has finished recruiting patients with tibia plateau fractures needing augmentation using this injectable bone graft in comparison to autograft [69]. The final results are due soon. Other frequently used synthetic bone grafts are polylactic acid, polyglycolic acid, polycaprolactone, and their respective copolymers [70]. Those polymers are softer than the ceramic biomaterials. Thereby, they are highly flexible. Because of these characteristics, they can be more easily processed than ceramic materials. These polymers are biodegradable and biocompatible. However, the resorption time needs also to be taken into account. Polylactic acid sometimes degrades too fast, and polycaprolactone has been found in bone defects 2 years after implantation. These materials, however, can be easily loaded with growth factors to add osteoconductivity. Polymers, however, possess insufficient mechanical strength and stiffness compared to natural bone. Therefore, they are often used in combination with ceramic materials such as hydroxyapatite or β-tricalcium phosphate [71]. The combination of polycaprolactone with tricalcium phosphate has been used to reconstruct large craniofacial defects with good outcome [72]. A study at the National University Hospital in Singapore showed good results in 80 patients undergoing reconstruction of orbital fractures with polycaprolactone/tricalcium phosphate scaffolds [73]. A similar scaffold has been used in a case of non-union at the tibia plateau [74]. Although polymer-based synthetic bone grafts show clinically satisfactory results in these small studies and cases, in the daily clinical routine they are hardly used. This may be partially also

203

due to minimal, commercialization of these products. Therefore, the synthetic bone graft market is dominated by hydroxyapatite and tricalcium phosphate-based products.

20.3 I ndications for Use of Bone Grafts Bone grafts are needed, where the defect healing without the bone graft would not occur. This is the case for segmental bone defects with a length larger than 1.5 times the diameter of the bone [75]. In such cases the distance between the proximal and distal end is too large to be naturally bridged by intrinsic bone regeneration. Cases wherein bone healing has been tried by other means than bone grafts, but failed to regenerate bone, are also indications for bone grafting. The non-healing of such fractures can have many different causes such as insufficient stability, patient intrinsic effectors (e.g., diabetes, osteoporosis, smoking, obesity, contraceptive medication, etc.), infections, circulation disorders, etc. When the defects are so large that not enough autologous bone material can be harvested to fill the gap, allografts, xenografts, or synthetic biomaterials have to be considered. As described above, also combinations of all the graft types can be used. Furthermore, to increase the osteogenic potential of grafts without cells, bone marrow or mesenchymal stem cells could be added. Other indications are large defects during revision total knee arthroplasty. Graft administration can also be used in the open space that is created during high tibial osteotomies. However, in opening angles less than 10°, it is not recommended to use synthetic augmentation. Autografts should be used in patients with opening angles larger than 10° and at risk for non-union due to factors described above [76]. In the case of infections, it is absolutely necessary to first debride the defect until no microorganisms can be detected anymore. If necessary, the defect needs to be enlarged as the necrotic, or highly infected bone material at the proximal or distal ends needs to be removed. Only then, grafting should be performed.

204

References 1. Gaston MS, Simpson AH. Inhibition of fracture healing. J Bone Joint Surg Br. 2007;89:1553–60. 2. Brydone AS, Meek D, Maclaine S.  Bone grafting, orthopaedic biomaterials, and the clinical need for bone engineering. Proc Inst Mech Eng H. 2010;224:1329–43. 3. Giannoudis PV, Einhorn TA, Marsh D. Fracture healing: the diamond concept. Injury. 2007;38(Suppl 4):S3–6. 4. Giannoudis PV, Einhorn TA, Schmidmaier G, Marsh D.  The diamond concept—open questions. Injury. 2008;39(Suppl 2):S5–8. 5. Calori GM, Mazza E, Colombo M, Ripamonti C. The use of bone-graft substitutes in large bone defects: any specific needs? Injury. 2011;42(Suppl 2):S56–63. 6. Schmidmaier G, Herrmann S, Green J, Weber T, Scharfenberger A, Haas NP, Wildemann B. Quantitative assessment of growth factors in reaming aspirate, iliac crest, and platelet preparation. Bone. 2006;39:1156–63. 7. Pape HC, Evans A, Kobbe P.  Autologous bone graft: properties and techniques. J Orthop Trauma. 2010;24(Suppl 1):S36–40. 8. Burchardt H. Biology of bone transplantation. Orthop Clin North Am. 1987;18:187–96. 9. Husebye EE, Lyberg T, Opdahl H, Laurvik H, Roise O. Cardiopulmonary response to reamed intramedullary nailing of the femur comparing traditional reaming with a one-step reamer-irrigator-aspirator reaming system: an experimental study in pigs. J Trauma. 2010;69:E6–14. 10. Mueller CA, Rahn BA.  Intramedullary pressure increase and increase in cortical temperature during reaming of the femoral medullary cavity: the effect of draining the medullary contents before reaming. J Trauma. 2003;55:495–503. discussion 503 11. Higgins TF, Casey V, Bachus K. Cortical heat generation using an irrigating/aspirating single-pass reaming vs conventional stepwise reaming. J Orthop Trauma. 2007;21:192–7. 12. Hammer TO, Wieling R, Green JM, Sudkamp NP, Schneider E, Muller CA. Effect of re-implanted particles from intramedullary reaming on mechanical properties and callus formation. A laboratory study. J Bone Joint Surg Br. 2007;89:1534–8. 13. Conway JD.  Autograft and nonunions: morbidity with intramedullary bone graft versus iliac crest bone graft. Orthop Clin North Am. 2010;41:75–84; table of contents. 14. Seagrave RA, Sojka J, Goodyear A, Munns SW.  Utilizing reamer irrigator aspirator (RIA) autograft for opening wedge high tibial osteotomy: a new surgical technique and report of three cases. Int J Surg Case Rep. 2014;5:37–42. 15. Stafford PR, Norris BL.  Reamer-irrigator-aspirator bone graft and bi Masquelet technique for segmental bone defect nonunions: a review of 25 cases. Injury. 2010;41(Suppl 2):S72–7.

M. van Griensven 16. Giannoudis PV, Tzioupis C, Green J.  Surgical techniques: how I do it? The Reamer/Irrigator/Aspirator (RIA) system. Injury. 2009;40:1231–6. 17. Frolke JP, Nulend JK, Semeins CM, Bakker FC, Patka P, Haarman HJ. Viable osteoblastic potential of cortical reamings from intramedullary nailing. J Orthop Res. 2004;22:1271–5. 18. Blokhuis TJ, Calori GM, Schmidmaier G. Autograft versus BMPs for the treatment of non-unions: what is the evidence? Injury. 2013;44(Suppl 1):S40–2. 19. Giannoudis PV, Ahmad MA, Mineo GV, Tosounidis TI, Calori GM, Kanakaris NK.  Subtrochanteric fracture non-unions with implant failure managed with the “Diamond” concept. Injury. 2013;44(Suppl 1):S76–81. 20. Sagi HC, Young ML, Gerstenfeld L, Einhorn TA, Tornetta P.  Qualitative and quantitative differences between bone graft obtained from the medullary canal (with a Reamer/Irrigator/Aspirator) and the iliac crest of the same patient. J Bone Joint Surg Am. 2012;94:2128–35. 21. Frolke JP, Bakker FC, Patka P, Haarman HJ. Reaming debris in osteotomized sheep tibiae. J Trauma. 2001;50:65–9. Discussion 69–70 22. Trinkaus K, Wenisch S, Siemers C, Hose D, Schnettler R. [Reaming debris: a source of vital cells! First results of human specimens]. Unfallchirurg. 2005;108:650–6. 23. Wenisch S, Trinkaus K, Hild A, Hose D, Herde K, Heiss C, Kilian O, Alt V, Schnettler R. Human reaming debris: a source of multipotent stem cells. Bone. 2005;36:74–83. 24. Cox G, McGonagle D, Boxall SA, Buckley CT, Jones E, Giannoudis PV.  The use of the reamer-irrigator-­ aspirator to harvest mesenchymal stem cells. J Bone Joint Surg Br. 2011;93:517–24. 25. Dimitriou R, Mataliotakis GI, Angoules AG, Kanakaris NK, Giannoudis PV.  Complications following autologous bone graft harvesting from the iliac crest and using the RIA: a systematic review. Injury. 2011;42(Suppl 2):S3–15. 26. Pratt DJ, Papagiannopoulos G, Rees PH, Quinnell R. The effects of medullary reaming on the torsional strength of the femur. Injury. 1987;18:177–9. 27. Lowe JA, Della Rocca GJ, Murtha Y, Liporace FA, Stover MD, Nork SE, Crist BD. Complications associated with negative pressure reaming for harvesting autologous bone graft: a case series. J Orthop Trauma. 2010;24:46–52. 28. Krettek C, Schandelmaier P, Tscherne H. Nonreamed interlocking nailing of closed tibial fractures with severe soft tissue injury. Clin Orthop Relat Res. 1995;34–47. 29. McCall TA, Brokaw DS, Jelen BA, Scheid DK, Scharfenberger AV, Maar DC, Green JM, Shipps MR, Stone MB, Musapatika D, Weber TG.  Treatment of large segmental bone defects with reamer-irrigator-­ aspirator bone graft: technique and case series. Orthop Clin North Am. 201041:63–73; table of contents.

20  Posttraumatic Bone Defects Around the Knee 30. Husebye EE, Opdahl H, Roise O, Aspelin T, Lyberg T. Coagulation, fibrinolysis and cytokine responses to intramedullary nailing of the femur: an experimental study in pigs comparing traditional reaming and reaming with a one-step reamer-irrigator-aspirator system. Injury. 2011;42:630–7. 31. Seiler JG 3rd, Johnson J. Iliac crest autogenous bone grafting: donor site complications. J South Orthop Assoc. 2000;9:91–7. 32. Bae H, Zhao L, Zhu D, Kanim LE, Wang JC, Delamarter RB. Variability across ten production lots of a single demineralized bone matrix product. J Bone Joint Surg Am. 2010;92:427–35. 33. Brune JC, Hesselbarth U, Seifert P, Nowack D, von Versen R, Smith MD, Seifert D.  CT lesion model-­ based structural allografts: custom fabrication and clinical experience. Transfus Med Hemother. 2012;39:395–404. 34. Malhotra R, Garg B, Kumar V. Dual massive skeletal allograft in revision total knee arthroplasty. Indian J Orthop. 2011;45:368–71. 35. Struckmann V, Schmidmaier G, Ferbert T, Kneser U, Kremer T.  Reconstruction of extended bone defects using massive allografts combined with surgical angiogenesis: a case report. JBJS Case Connect. 2017;7:e10. 36. Tomford WW. Transmission of disease through transplantation of musculoskeletal allografts. J Bone Joint Surg Am. 1995;77:1742–54. 37. Chun CH, Kim JW, Kim SH, Kim BG, Chun KC, Kim KM.  Clinical and radiological results of femoral head structural allograft for severe bone defects in revision TKA—a minimum 8-year follow-up. Knee. 2014;21:420–3. 38. Engh GA, Ammeen DJ.  Use of structural allograft in revision total knee arthroplasty in knees with severe tibial bone loss. J Bone Joint Surg Am. 2007;89:2640–7. 39. Ghazavi MT, Stockley I, Yee G, Davis A, Gross AE.  Reconstruction of massive bone defects with allograft in revision total knee arthroplasty. J Bone Joint Surg Am. 1997;79:17–25. 40. Gharedaghi M, Peivandi MT, Mazloomi M, Shoorin HR, Hasani M, Seyf P, Khazaee F. Evaluation of clinical results and complications of structural allograft reconstruction after bone tumor surgery. Arch Bone Jt Surg. 2016;4:236–42. 41. Kanakeshwar RB, Jayaramaraju D, Agraharam D, Rajasekaran S. Management of resistant distal femur non-unions with allograft strut and autografts combined with osteosynthesis in a series of 22 patients. Injury. 2017;48(Suppl 2):S14–s17. 42. Jean JL, Wang SJ, Au MK. Treatment of a large segmental bone defect with allograft and autogenous bone marrow graft. J Formos Med Assoc. 1997;96:553–7. 43. Attias N, Lindsey RW. Case reports: management of large segmental tibial defects using a cylindrical mesh cage. Clin Orthop Relat Res. 2006;450:259–66. 44. Al Qabbani A, Al Kawas S, Razak NHA, Al Bayatti SW, Enezei HH, Samsudin AR, Sheikh Ab Hamid

205 S.  Three-dimensional radiological assessment of alveolar bone volume preservation using bovine bone xenograft. J Craniofac Surg. 2018;29:e203–9. 45. Guarnieri R, DeVilliers P, Belleggia F.  GBR using cross-linked collagen membrane and a new highly purified bovine xenograft (Laddec) in horizontal ridge augmentation: case report of clinical and histomorphometric analysis. Quintessence Int. 2015;46:717–24. 46. Aghazadeh A, Rutger Persson G, Renvert S. A single-­ centre randomized controlled clinical trial on the adjunct treatment of intra-bony defects with autogenous bone or a xenograft: results after 12 months. J Clin Periodontol. 2012;39:666–73. 47. Hess T, Gleitz M, Hanser U, Mittelmeier H, Kubale R. [Primary stability of autologous and heterologous implants for intervertebral body spondylodesis]. Z Orthop Ihre Grenzgeb. 1995;133:222–6. 48. Kubosch EJ, Bernstein A, Wolf L, Fretwurst T, Nelson K, Schmal H. Clinical trial and in-vitro study comparing the efficacy of treating bony lesions with allografts versus synthetic or highly-processed xenogeneic bone grafts. BMC Musculoskelet Disord. 2016;17:77. 49. Ribeiro TA, Coussirat C, Pagnussato F, Diesel CV, Macedo FC, Macedo CA, Galia CR.  Lyophilized xenograft: a case series of histological analysis of biopsies. Cell Tissue Bank. 2015;16:227–33. 50. Makridis KG, Ahmad MA, Kanakaris NK, Fragkakis EM, Giannoudis PV.  Reconstruction of iliac crest with bovine cancellous allograft after bone graft harvest for symphysis pubis arthrodesis. Int Orthop. 2012;36:1701–7. 51. Meyer S, Floerkemeier T, Windhagen H. Histological osseointegration of Tutobone: first results in human. Arch Orthop Trauma Surg. 2008;128:539–44. 52. Wang ZG, Liu J, Hu YY, Meng GL, Jin GL, Yuan Z, Wang HQ, Dai XW.  Treatment of tibial defect and bone nonunion with limb shortening with external fixator and reconstituted bone xenograft. Chin J Traumatol. 2003;6:91–8. 53. Tsai WC, Liao CJ, Wu CT, Liu CY, Lin SC, Young TH, Wu SS, Liu HC. Clinical result of sintered bovine hydroxyapatite bone substitute: analysis of the interface reaction between tissue and bone substitute. J Orthop Sci. 2010;15:223–32. 54. Khan SN, Tomin E, Lane JM.  Clinical applications of bone graft substitutes. Orthop Clin North Am. 2000;31:389–98. 55. Hanke A, Baumlein M, Lang S, Gueorguiev B, Nerlich M, Perren T, Rillmann P, Ryf C, Miclau T, Loibl M.  Long-term radiographic appearance of calcium-phosphate synthetic bone grafts after ­surgical treatment of tibial plateau fractures. Injury. 2017;48:2807–13. 56. Onodera J, Kondo E, Omizu N, Ueda D, Yagi T, Yasuda K.  Beta-tricalcium phosphate shows superior absorption rate and osteoconductivity compared to hydroxyapatite in open-wedge high tibial osteotomy. Knee Surg Sports Traumatol Arthrosc. 2014;22:2763–70.

206 57. Epstein NE.  Beta tricalcium phosphate: observation of use in 100 posterolateral lumbar instrumented fusions. Spine J. 2009;9:630–8. 58. Ogose A, Hotta T, Kawashima H, Kondo N, Gu W, Kamura T, Endo N.  Comparison of hydroxyapatite and beta tricalcium phosphate as bone substitutes after excision of bone tumors. J Biomed Mater Res B Appl Biomater. 2005;72:94–101. 59. Rolvien T, Barvencik F, Klatte TO, Busse B, Hahn M, Rueger JM, Rupprecht M. ss-TCP bone substitutes in tibial plateau depression fractures. Knee. 2017;24:1138–45. 60. Shen C, Ma J, Chen XD, Dai LY.  The use of beta-­ TCP in the surgical treatment of tibial plateau fractures. Knee Surg Sports Traumatol Arthrosc. 2009;17:1406–11. 61. Sakamoto A.  Reconstruction with beta-tricalcium phosphate for giant cell tumor of bone around the knee. J Knee Surg. 2017;30:75–7. 62. Choi WC, Kim B, Kim U, Lee Y, Kim JH. Gap healing after medial open-wedge high tibial osteotomy using injectable beta-tricalcium phosphate. J Orthop Surg (Hong Kong). 2017;25: 2309499017727942. 63. Hernigou P, Roussignol X, Flouzat-Lachaniette CH, Filippini P, Guissou I, Poignard A.  Opening wedge tibial osteotomy for large varus deformity with Ceraver resorbable beta tricalcium phosphate wedges. Int Orthop. 2010;34:191–9. 64. Takeuchi R, Bito H, Akamatsu Y, Shiraishi T, Morishita S, Koshino T, Saito T. In vitro stability of open wedge high tibial osteotomy with synthetic bone graft. Knee. 2010;17:217–20. 65. Moro-Barrero L, Acebal-Cortina G, Suarez-Suarez M, Perez-Redondo J, Murcia-Mazon A, Lopez-Muniz A. Radiographic analysis of fusion mass using fresh autologous bone marrow with ceramic composites as an alternative to autologous bone graft. J Spinal Disord Tech. 2007;20:409–15. 66. Friedmann A, Dard M, Kleber BM, Bernimoulin JP, Bosshardt DD.  Ridge augmentation and maxillary sinus grafting with a biphasic calcium phosphate: histologic and histomorphometric observations. Clin Oral Implants Res. 2009;20:708–14.

M. van Griensven 67. Blom AW, Wylde V, Livesey C, Whitehouse MR, Eastaugh-Waring S, Bannister GC, Learmonth ID. Impaction bone grafting of the acetabulum at hip revision using a mix of bone chips and a biphasic porous ceramic bone graft substitute. Acta Orthop. 2009;80:150–4. 68. Nilsson M, Fernandez E, Sarda S, Lidgren L, Planell JA.  Characterization of a novel calcium phosphate/sulphate bone cement. J Biomed Mater Res. 2002;61:600–7. 69. Nusselt T, Hofmann A, Wachtlin D, Gorbulev S, Rommens PM.  CERAMENT treatment of fracture defects (CERTiFy): protocol for a prospective, multicenter, randomized study investigating the use of CERAMENT BONE VOID FILLER in tibial plateau fractures. Trials. 2014;15:75. 70. Polo-Corrales L, Latorre-Esteves M, Ramirez-Vick JE. Scaffold design for bone regeneration. J Nanosci Nanotechnol. 2014;14:15–56. 71. Barber FA, Spenciner DB, Bhattacharyya S, Miller LE. Biocomposite implants composed of poly(lactide-­ co-­ glycolide)/beta-tricalcium phosphate: systematic review of imaging, complication, and performance outcomes. Arthroscopy. 2017;33:683–9. 72. Probst FA, Hutmacher DW, Muller DF, Machens HG, Schantz JT. [Calvarial reconstruction by customized bioactive implant]. Handchir Mikrochir Plast Chir. 2010;42:369–73. 73. National University Hospital Singapore. Polycaprolactone/tricalcium phosphate (PCL/ TCP) v titanium orbital implant: randomised trial. ClinicalTrial.gov Identifier: NCT01119144; 2014. 74. van Griensven M, Biberthaler P, Rosado Balmayor E.  Clinical approaches to the healing of long bone defects. In: Schantz JT, Hutmacher DW, editors. Advanced therapies in regenerative medicine. Singapore: World Scientific; 2015. p. 217–31. 75. Key JA. The effect of a local calcium depot on osteogenesis and healing of fractures. J Bone Joint Surg Am. 1934;16:176–84. 76. Aryee S, Imhoff AB, Rose T, Tischer T. Do we need synthetic osteotomy augmentation materials for opening-wedge high tibial osteotomy. Biomaterials. 2008;29:3497–502.

Management of Ligament Injuries Following Fractures Around the Knee

21

John Keating

21.1 Epidemiology of Ligament Injuries Following Fractures Around the Knee Ligament injuries and other soft tissue injuries around the knee in association with fractures are usually a result of high-energy trauma. They occur most commonly in young male adults. Distal femoral fractures and proximal tibial fractures are now most common in older patients, and in these patients osteoporosis is a common feature, and the majority of fractures around the knee is therefore a result of low-energy trauma. The age distribution of a consecutive series of 888 tibial plateau fractures presenting to the Edinburgh Orthopaedic Trauma Unit is presented in Fig. 21.1. It can be seen this is a bimodal distribution with a major peak in patients between the age of 60 and 80 years and a smaller peak in younger adults with, in general, higher-energy trauma. The same age distribution pattern is associated with distal femoral fractures. It is the younger age group with higher-energy trauma who are most at risk of having associated relevant soft tissue injuries that may also need to be addressed as part of their management.

J. Keating (*) The University of Edinburgh, New Royal Infirmary of Edinburgh, Trauma and Orthopaedic Surgery, Edinburgh, Great Britain, UK e-mail: [email protected]

21.1.1 Peri-articular Fractures and Soft Tissue Injury Studies reporting clinical and arthroscopic findings in patients with femoral shaft fractures, distal femoral fractures and tibial plateau fractures have reported significant rates of associated soft tissue injuries, predominantly involving meniscal tears and ligament injuries [1, 2]). Meybodi et al. [1] reported on 44 femoral shaft fractures and evaluated the ipsilateral knee based on a combination of clinical examination, assessment during retrograde nailing and some arthroscopic examinations. They reported a 27% incidence of meniscal tears and a high rate of ACL injury (41%). However, there were only two complete ACL tears and two incomplete PCL tears in the series. They did not specify how unstable the meniscal tears were. They also reported some MCL and PLC laxity in 34% and 9% of patients, respectively. They did not specify whether any of these ligament injuries required surgical reconstruction. Ebrahimzadeh et  al. [2] reported the clinical findings on examination of the knee in 80 patients who had undergone internal fixation of distal femoral and tibial plateau fractures. They reported evidence of anterior and posterior instability in 42% and 24% of distal femur fractures and 26% and 7% of plateau fractures, respectively. Medial instability and lateral instability were found in 50% and 28% of femur fractures

© Springer Nature Switzerland AG 2021 M. Hanschen et al. (eds.), Knee Fractures, Strategies in Fracture Treatments, https://doi.org/10.1007/978-3-030-81776-3_21

207

J. Keating

208

20

15

10

5

0

80

Fig. 21.1  Age distribution of fractures around the knee. There is a bimodal distribution with a peak of higher energy fractures in younger adults and a later peak of osteoporotic fractures in older age groups

and 24% and 14% of tibial plateau fractures, respectively. The need for surgical reconstruction for ligament instability was not specified, but almost 80% of patients in both fractures groups had good to excellent results using the Lysholm score. Studies of MRI scanning after distal femoral fractures and tibial plateau fractures have reported high rates of soft tissue injuries. In particular lateral tibial plateau fractures are associated with a high incidence of medial collateral ligament (MCL) sprains and meniscal injuries. In an early study, Colletti et  al. [3] reported on 29 patients with tibial plateau fractures and noted soft tissue abnormalities in 97% of cases. Shepherd et al. [4] reported on MRI scans in 20 patients with undisplaced tibial plateau fractures and noted soft tissue abnormalities in 18 (90%). They indicated that 80% had meniscal tears and 40% had what they described as complete ligament tears. More recent studies have confirmed these findings in larger patient cohorts. Gardner et al. [5] reported on MRI scan findings in 103 displaced tibial plateau fractures and reported that only 1 patient had no soft tissue abnormalities. They noted that 79 patients (77%) sustained a complete tear or avulsion of 1 or more cruciate or collateral ligaments. They also found that 94 patients (91%) had evidence of lateral meniscus pathology and 45 patients (44%) had medial meniscus tears.

Seventy patients (68%) had tears of one or more of the posterolateral corner structures of the knee. Despite these studies, combinations of fractures and significant soft tissue knee disruptions requiring repair are uncommon. Warner et al. [6] reported on outcomes of 82 tibial plateau fractures treated by internal fixation with reference to the need for subsequent soft tissue surgery. Although 73% of patients had soft tissue abnormalities on the preoperative MRI scan, only 2 patients (2%) required a subsequent soft tissue surgical procedure. Similarly in 448 patients with peri-articular knee fractures, Kim et  al. [7] reported PCL injury in only 7.8% of cases. The published literature on operative management of peri-articular knee fractures is characterised by a lack of either concomitant or delayed soft tissue knee surgery being required. It seems probable therefore that many of the soft tissue abnormalities picked up on MRI scanning, which is a sensitive form of imaging, are not of sufficient clinical importance to merit surgical reconstruction. In the majority of cases, these are not high-grade injuries, and they very rarely result in any late medial instability. Significant ligament and soft tissue injuries are even less common with distal femoral fractures. PCL tears are associated with both tibial plateau and femoral shaft fractures but are actually very rare after distal femoral fractures [7]. They

21  Management of Ligament Injuries Following Fractures Around the Knee

are quite common after head on collisions when the tibia is forced directly posterior, rupturing the ligament. A high index of suspicions is needed to consider these injuries in younger patients with high-energy femoral shaft fractures. Tibial spine avulsions can occur at any age. Anterior tibial spine fractures are more common than PCL bony avulsions. In adult orthopaedic practice, the mean age of these injuries is 35 years, and they are twice as common in men [8]. In contrast to PCL avulsions, they are more commonly associated with simple falls or sporting injuries in 83% of cases. PCL bony avulsions are less common and are most commonly sustained as the result of high-­ energy motor vehicle accidents in 68% of cases. In a systematic review, Hooper et al. [9] reported on 28 studies including 637 patients that had tibial PCL avulsion injuries. Concomitant meniscal tears were present in 16.8%, and these were more commonly involved the medial meniscus. Concomitant ligament injuries were present in 19% of cases, and these were evenly distributed between MCL, posterolateral corner and ACL tears. The Segond fracture is an avulsion from the anterolateral rim of the tibial plateau. It is almost always associated with an ACL tear. It is now generally considered to be an avulsion of the anterolateral ligament complex, and the fragment is attached to posterior fibres of the ITB and the lateral capsule in 94% of cases ([10]; Fig. 21.2). The incidence of this fractures in patients with ACL tears is 6% [11]. A so-called reverse Segond fracFig. 21.2 AP radiograph of the knee showing a Segond fracture, an avulsion fracture adjacent to the lateral plateau, usually associated with a concomitant ACL tear

209

ture has also been described [12] which is medial plateau avulsion fracture said to be associated with PCL disruption, but this avulsion fracture pattern is not common in clinical practice, and relatively few cases have been reported [13]. Finally anteromedial plateau fractures should alert the surgeon of the possibility of a posterolateral corner disruption or an associated PCL tear. This pattern of fracture is characteristically associated with a hyperextension and varus deformity causing the PCL injury, and PLC disruption may occur [14, 15].

21.2 Clinical Assessment and Imaging The assessment of patients with peri-articular knee fractures and concomitant soft tissue knee injuries is challenging. The usual clinical diagnostic tests will generally not be possible in the presence of an unstable distal femoral or proximal tibial fracture. The presence of a lateral tibial plateau fracture, for example, renders it impossible to perform a meaningful examination of the medial collateral ligament, due to the combination of pain and instability of the knee with valgus force due to the presence of the fracture. Since many of these patients have other injuries elsewhere, a careful clinical evaluation consistent with ATLS guidelines is appropriate for patients presenting after high-energy trauma. Locally it is important to assess soft tissues around the knee since the presence of extensive

210

J. Keating

skin damage or blistering will influence timing should be considered for angiography if there is and the nature of surgery. Vascular injury is any history or physical finding to suggest ischuncommon but is a well-recognised risk of frac- aemia at any stage. ture dislocation patterns in particular, and documentation of the vascular integrity of the limb is essential. The common peroneal nerve is vulner- 21.3 Meniscal Injury able to injury in fractures that result from varus forces. Medial tibial plateau fractures are associ- Meniscal tears can occur with distal femoral and ated with common peroneal nerve palsy in 11% tibial plateau fractures. However, they are most of cases, so documentation of the neurological commonly associated with tibial plateau fracstatus of the limb is important so complication is tures and in particular with split and split depresdetected prior to any surgical intervention. sion patterns of the lateral plateau [16]. In our Finally higher-energy fractures and dislocations series of these injuries, lateral meniscal detachare associated with a risk of developing compart- ments occurred in 26% of split depression fracment syndrome. If there is any diagnostic doubt ture cases, an incidence identical to that reported about this, measurement of compartment pres- by Wang et al. [17], and are always on the same sures in the leg is advisable. side as the fracture. Small radial tears can also Plain radiographs will reveal fractures but for occur frequently, but these are not mechanically complex patterns are not adequate alone to define unstable and seldom require any form of surgical the anatomy of the injury. For the bony compo- intervention. In the case of the more common nent, CT scans are necessary in the majority of peripheral tear, it usually involves the lateral cases to accurately define the fracture anatomy. meniscus in association with lateral plateau fracCoronal and sagittal 2D reconstructions are very tures. The anterior half of the lateral meniscus is useful supplementary images. They are particu- typically detached, displaced towards the medial larly helpful for visualising the extent of involve- side, and it can become incarcerated in the fracment and fracture planes that can be difficult to ture, blocking reduction (Fig.  21.3). The incisee and evaluate on plain radiographs. This would dence of meniscal tears rises with increased include Hoffa fractures in the distal femur and displacement of the fracture. Tibial plateau widdisplacement of anterior and posterior tibial spine ening in association with fractures increases the components of plateau fractures. Three-­risk of associated soft tissue injury, particularly dimensional reconstructions of complex fracture meniscal tears [18]. In general widening of patterns can also be very helpful in clarifying greater than 7  mm is associated with a higher complex fracture patterns and in the case of the incidence of meniscal tears [17]. Caution must be plateau in particular may influence the choice of exercised particularly if percutaneous fixation of surgical approach. displaced split fractures is being contemplated MRI scanning if performed routinely on peri-­ without direct visualisation of the articular surarticular knee fractures will demonstrate a high face. Either preoperative imaging with an MRI incidence of soft tissue injury. In the majority of scan or intra-operative visualisation of the meniscases, the meniscal and ligament lesions will not cus by arthroscopy is necessary to verify the lead to late symptoms requiring reconstruction. meniscus is reduced before percutaneous reducTherefore MRI scanning should be performed in tion is attempted. fractures at high risk of associated ligament and Medial meniscal tears also occur with dismeniscal injury. This should be considered par- placement of medial plateau fractures, but these ticularly in hyperextension recurvatum patterns are less common. In the case of both the medial of plateau fracture or tibial spine avulsion frac- and lateral meniscus mechanically unstable, the tures with suspected involvement of other liga- tears are typically peripheral detachments in ments. Finally fracture dislocations of the knee most cases, and therefore repair with preservamay be associated with vascular injury and tion of the meniscus is preferable to meniscec-

21  Management of Ligament Injuries Following Fractures Around the Knee

211

Fig. 21.3 Antero-lateral arthrotomy showing detachment of the anterior half of the lateral meniscus associated with a lateral plateau fracture. Arrowing pointing at detached meniscus

tomy and is associated with a low risk of recurrent tears. The surgical technique most commonly involves open exposure of the fracture and repositioning of the meniscus using stay sutures to elevate it away from the fracture plane, allowing reduction of the fracture. Once the fracture has been fixed, the meniscus can then be reattached to the capsular bed with interrupted sutures or using meniscal repair anchors. Because the repair is performed in a well-vascularised peripheral area of the meniscus, failure is rare. Key surgical steps in dealing with displaced lateral meniscal tears in lateral plateau fractures: • Expose lateral plateau. • Perform anterolateral arthrotomy above level of meniscus. • Evacuate haemarthrosis. • Extend arthrotomy inferiorly to allow identification of meniscus.

• If there is a meniscal detachment, use stay suture to exert traction on anterior horn. • Elevate lateral meniscus out of fracture plane if required. • Clean and reduce fracture. • Place interrupted meniscal repair sutures from peripheral edge of meniscus-to-meniscus ­capsular attachment starting at the most posterior extent. • Fix lateral plateau fracture. • Tie meniscus sutures proceeding from posterior to anterior. • Close arthrotomy.

21.4 Collateral Ligament Injury As noted above, studies of peri-articular fractures indicate that injuries to the collateral ligament complexes may occur with any fracture type. There is a high rate of MCL sprains associated with lateral plateau fractures, and this is a com-

212

mon pattern of injury in clinical practice. In the majority these are grade I or II sprains, and surgery is therefore very rarely required acutely. Once the fracture has been fixed, an examination under anaesthesia can be performed. The use of a hinged knee bracing may be considered for 6  weeks postoperatively if there is evidence of laxity on clinical examination. No brace is necessary if the MCL is judged to be stable. In general most MCL, sprains will heal without the need for reconstruction at a later stage. In the small proportion of cases who have residual instability, a late reconstruction can be performed. MCL sprains of the knee are very common following sporting injury but are only rarely associated with bony avulsions, and this usually occurs at the site of the femoral attachment. Calcification in the region of the medial femoral condyle following medial collateral ligament sprains (MCL) is often referred to as Pellegrini-Stieda syndrome ([19, 20]; Fig. 21.4). This is thought to be due to avulsion of the insertion with subsequent calcification. It is associated with 7% of MCL sprains and is associated with a more prolonged clinical recovery. There are a variety of surgical techniques which can be used to carry out MCL reconstruction. Currently my preferred option is to use an autogenous hamstring tendon (usually semitendinosus) which can be harvested at the level of the pes anserinus. I leave the tendon attached distally, and then attach the free end to the insertion point of the MCL on the medial condyle. There is usually enough length of tendon to bring the free end down to the level of the pes anserinus insertion where it can be sutured back to the distal tendon. Following this reconstruction patients can be mobilised in a hinged knee brace with full extension and 90 degrees of knee flexion for 6 weeks and can then be weaned out of the brace. Posterolateral ligament complex injury is associated with anteromedial tibial plateau fractures (Fig. 21.5). In addition to a CT scan to show the fracture configuration, these fractures should have an MRI scan prior to surgery to define the extent of ligament injury since in addition to the PLC disruption there may also be a PCL tear. This injury pattern is associated with a risk of

J. Keating

common peroneal nerve palsy, so clinical assessment of the nerve is necessary prior to surgery. Fixation of the fracture is most commonly achieved by use of a medial buttress plate. The medial plateau can be exposed via an anteromedial incision with subperiosteal elevation of the MCL and pes anserinus to gain access to the anteromedial plateau. In most cases the intra-­ articular configuration of the fracture is not complex, and an arthrotomy is not always required. There may however be quite a lot of comminution at the site of the fracture on the subchondral bone of the medial plateau. Occasionally support of this area is required to achieve stable fixation. This may be with autogenous bone graft, allograft femoral head or calcium phosphate bone cement. The management of the posterolateral corner injury depends on the degree of laxity, and this is best assessed clinically following fixation irrespective of MRI scan appearances. After fixation of the fracture, patients with significant laxity in full extension are best treated surgically. Patients with minimal laxity on varus stress testing in full extension can be treated in a hinged brace, with the same protocol as outlined for those with MCL sprains. Patients with significant instability in full extension due to PLC disruption will require surgical repair or reconstruction. The timing of this is dependent on complexity of the associated fracture and the fixation required. If the fracture is a simple anteromedial fracture which can be treated with buttress plating in a short duration of time, then the posterolateral exploration and surgery can be undertaken at the same time. If the fracture configuration is complex, for example, an oblique split depression pattern then the bony reconstruction may be time-consuming, and extending the tourniquet time to carry out a posterolateral corner reconstruction may increase the risk of postoperative complications. In this situation the procedures may need to be staged with an exploration of the posterolateral corner 5–7 days after fracture fixation. One advantage of simultaneous fracture fixation and posterolateral corner exploration is that the hamstring tendons can be harvested from the medial side if required to use on the posterolateral side if required.

21  Management of Ligament Injuries Following Fractures Around the Knee

213

Fig. 21.4 Calcification adacent to medial condyle is often called Pellegrini-Stieda syndrome and is an occasional complication of a medial collateral ligament injury, and usually associated with a prolonged recovery

For patients who do have posterolateral corner instability, the main options are a surgical repair and reconstruction. If the posterolateral corner structures have been detached in a single layer from the fibular head and proximal fibula which is commonly the case, then reattachment using suture anchors to repair the posterolateral corner is possible. If there is a more complex disruption with mid-substance tears of the components of the posterolateral corner, then repair of individual

structures can be attempted, but consideration should be given to reinforcing the repair by means of a reconstructive technique usually using either autogenous hamstring tendons or allograft tendons to reconstruct the components of the posterolateral corner which have been disrupted [21]. Numerous techniques have been described to address the various aspects of the injury, but there is still a lot of variation in surgical techniques being used in current practice [22].

J. Keating

214 a

e

b

c

f

d

g

Fig. 21.5 (a) Lateral and (b) ap view of anteromedial plateau fracture. This pattern of fracture is associated with PCL and posterolateral corner ligament injuries. (c) 3D CT reconstruction showing the characteristic anteromedial position of the fracture. (d) Distal pulses were not palpable and a CT angiogram confirmed a popliteal artery

injury. (e and f) MRI in the same patient confirmed complete tear of the PCL but intact ACL. (g) Management consisted of fracture fixation and vascular repair at the same sitting and subsequently a staged PCL reconstruction

21.5 Fibular Head Avulsion

is a tension band wire fixation which is almost always technically feasible even with small fragments or if there is comminution. Other soft tissue combinations of posterolateral corner injury such as capsular avulsion from the tibia can be reattached with suture anchors if required. Avulsion of the femoral insertion of the lateral collateral ligament has been described, but it is rare. If the fragment is large and displaced, then screw fixation is possible. If the fragment is small or comminuted, then a soft tissue repair or reconstruction can be performed.

Another variety of posterolateral corner involvement in complex fracture dislocations of the knee is fibular head avulsion (Fig. 21.6). This may be seen as part of a multi-ligament soft tissue injury or combined with a plateau fracture. The fibular head is the site of insertion of several important components of the posterolateral corner including the biceps femoris tendon, the lateral collateral ligament, the popliteofibular ligament and the fabellofibular ligament. Avulsion of the fibular head with displacement will therefore compromise posterolateral corner stability. Fixation should be undertaken for displaced fractures of the fibular head. Several techniques have been described. Although screw fixation is possible, this may not be secure if the fibular head avulsion is comminuted. A good alternative

21.6 Cruciate Ligament Injury Bony avulsions of the ACL or PCL are common fractures and can occur in isolation or in combination with more complex fracture patterns. ACL

21  Management of Ligament Injuries Following Fractures Around the Knee

a

b

d

215

c

e

Fig. 21.6 (a and b) AP and lateral posterolateral corner disruption and large Segond fracture with associated ACL tear. (c) MRI scan confirming the posterolateral corner

injury. (d and e) AP and lateral radiograph showing tension band wire of fibular head avulsion and screw fixation of Segond component of the injury

avulsions are more common than PCL avulsions (Fig.  21.7). Avulsion of tibial spine with the insertion of the ACL is seen in all age groups. It can be associated with other ligamentous injuries so clinical evaluation is important. More usually it is an isolated injury. Treatment depends on the degree of displacement. This is classified as three types based on the extent of displacement. Type I is undisplaced with only very slight elevation of the anterior tip of the spine. Type 2 is displaced with elevation of the anterior aspect of the spine. Type 3A is complete avulsion with elevation, and type 3B is complete avulsion with rotation of the fragment. The extent of displacement and judgement of the size of the fragment may be difficult

on the basis of the plain radiographs. CT scanning is the most useful additional imaging modality as it can be determined exactly how large the fragment is and the extent of displacement. Type I fractures can be treated non-operatively either in a cast or brace in full extension for the first 2–3  weeks following which flexion can be gradually introduced using a hinged brace which can be discontinued 6 weeks after injury. For displaced type 2 and type 3 fractures, fixation is the preferred option. Even type 2 fractures, which will heal, tend to result in a block to full knee extension due to impingement of the prominent spine in the region of the intercondylar notch. In the case of isolated tibial spine avulsions,

J. Keating

216

a

d

b

c

e

f

Fig. 21.7 (a and b) Posteromedial tibial plateau fracture with associated tibial spine avulsion. (c) 2D CT reconstruction showing tibial spine avulsion and large displaced posteromedial component. (d, e and f) Arthroscopic photo

of screw fixation of tibial spine and postoperative AP and lateral radiographs. Fixation of the posteromedial component was carried out initially followed by the arthroscopic fixation of the tibial spine fragment

arthroscopic reduction and fixation is sometimes possible. In cases where an accurate reduction cannot be achieved arthroscopically, then an anteromedial arthrotomy can be performed to facilitate accurate reduction. Screw placement should not be too anterior to reduce the risk of impingement. Postoperative management is as for type 1 fractures. In the majority of cases, a return to normal function can be expected. In 15% of cases, instability due to ACL laxity occurs presumably due to malunion with elongation of the ligament or due to damage to the ligament at the time of injury with subsequent lengthening and attenuation [8]. ACL may be required if there is sufficient symptomatic instability.

PCL bony avulsion is less common but can be classified and treated in a similar fashion (Fig. 21.8). Undisplaced fragments can be treated non-operatively. Fractures with displacement should be considered for operative treatment. Techniques for arthroscopic reduction have been described, but these are technically demanding [9]. Open reduction is an option but requires a posterior or posteromedial approach to the knee, so the surgery involved is more extensive than reattachment of the anterior tibial spine. If the fragment is small and comminuted, then non-­operative treatment in a PCL brace is a good option. Many patients will not experience troublesome instability, but for those that do an arthroscopic PCL

21  Management of Ligament Injuries Following Fractures Around the Knee

a

b

c

e

217

d

f

Fig. 21.8 (a and b) AP and lateral radiographs showing PCL bony avulsion. (c and d) 2D CT reconstructions demonstrating large bony PCL avulsion fragment. (e and

f) Postoperative radiographs showing fixation of the fragment which was fixed via a direct posteromedial exposure with the patient prone

reconstruction can be carried out at a later stage, and this can be done arthroscopically. Tibial spine fractures can occur in association with more complex plateau fractures. Reduction and fixation of the spine fragments can usually be accomplished via the surgical exposures used to address other components of the injury.

­Abdel-­Hamid et  al. [16] reported that ACL and PCL injuries were more common in medial tibial plateau and bicondylar plateau fracture types. The majority of these are bony avulsions as a component of the fracture. Mid-substance disruptions can occur but are uncommon and would account for less than 5% of cases.

218

J. Keating

21.7 Anteromedial Plateau Fractures

on the extent of comminution, involvement of the ACL and PCL attachments may occur. In addition to this, the lateral condyle tends to displace These are associated in particular with postero- into the fracture plane, and the posterolateral corlateral corner ligament injuries but may involve ner ligaments can be disrupted. Particular attention during clinical evaluation the PCL or ACL (Fig. 21.5). Chiba et al. (2001) to the neurovascular status of the limb is necesnoted that the pattern involved a small more antesary as there is an association with common perorior compression of the medial tibial plateau and was associated with PCL disruption. The associa- neal nerve palsy and vascular injury. These highly tion of this fracture type with ligament disruption unstable fracture patterns require internal fixation although recognised is not well documented in with buttress plating of the medial plateau. the literature with few cases being described [15]. Avulsion fragments involving ACL and PCL Management can follow the protocol described insertion may need to be incorporated into the above for when this fracture is associated with a fixation construct. If there is a complete posteroPLC injury. Surgery is more likely to need to be lateral corner disruption, then a simultaneous or staged since fixation of the fracture and simulta- staged reconstruction will be necessary. neous PCL/PLC reconstruction are time-­ Incomplete degrees of ligamentous injury are consuming and may not be possible to do in a often amenable to non-operative management in safe tourniquet time in a single sitting. Careful a brace. screw placement at the time of fracture fixation is necessary to allow for subsequent PCL recon- Summary  Fractures around the knee with associated soft struction, so ideally both components of the tissue injuries are a very heterogeneous group. As noted, injury should be managed by a surgeon with the if MRI scans are obtained in peri-articular knee fractures technical expertise to deal with both the bony and then there is a high incidence of concomitant soft tissue injuries. However, particularly with tibial plateau fracligamentous aspects of the injury. tures, soft tissue injuries do not necessarily require surgi-

21.8 O  blique Split Depression Fractures Tibial plateau fractures classified as a B3.3 pattern with the AO/OTA classification pattern are a form of fracture dislocation that does have a high incidence of associated soft tissue injury (Fig. 21.9). The oblique fracture plane typically is oriented from the inferomedial plateau and communicates with the intercondylar region or even extends into the lateral plateau. They are a result of high-energy trauma with marked varus deformity at the time of the fracture. Depending

cal treatment—collateral ligament injuries and cruciate ligament injuries are often incomplete and do well with non-operative treatment. Meniscal tears are common in associated plateau fractures, particularly with displaced lateral plateau fractures. The majority of these are peripheral detachments and can be treated surgically at the time of fixation. Bony avulsions of cruciate ligament insertions most commonly involve the tibial plateau. If displaced they will generally need consideration of fixation. Rarer patterns of injury such as anteromedial compression plateau fractures and the B3.3 oblique fracture are associated with more complex soft tissue injury patterns. These cases required a detailed preoperative evaluation that will involve several imaging modalities. They require careful surgical planning based on the pathology defined, and the surgeons undertaking the procedures require an expertise in fracture management and soft tissue knee reconstruction.

21  Management of Ligament Injuries Following Fractures Around the Knee

a

b

c

d

Fig. 21.9 (a and b) High energy oblique split depression fracture dislocation. These patterns of injury are very unstable fractures and are commonly associated with soft tissue injuries including PCL and posterolateral corner disruptions and common peroneal nerve palsy. (c and d)

219

2D and 3D reconstructions are useful in these patterns to define the exact anatomy of the fracture are very useful in formulating a surgical plan. (e and f) Postoperative radiograph showing good reduction with dual plates

J. Keating

220

e

f

Fig. 21.9 (continued)

References 1. Meybodi MKE, Ladani MJ, Meybodi TE, Rahimnia A, Dorostegan A, Abrisham J, Yarbeygi H. Concomitant ligamentous and meniscal knee injuries in femoral shaft fracture. J Orthopaed Traumatol. 2014;15:35–9. 2. Ebrahimzadeh MH, Birjandinejad A, Moradi A, Choghadeh MF, Rezazadeh J, Omidi-Kashani F.  Clinical instability of the knee and functional differences following tibial plateau fractures versus distal femoral fractures. Trauma Mon. 2015 February;20(1):e21635. 3. Colletti P, Greenberg H, Terk MR.  MR findings in patients with acute tibial plateau fractures. Comput Med Imaging Graph. 1996;20:389–94. 4. Shepherd L, Abdollahi K, Lee J, Vangsness CT. The prevalence of soft tissue injuries in nonoperative tibial plateau fractures as determined by magnetic resonance imaging. J Orthop Trauma. 2002;16(9):628–31. 5. Gardner MJ, Yacoubian S, Geller D, Suk M, Mintz D, Potter H, Helfet DL, Lorich DG. The incidence of soft tissue injury in operative tibial plateau fractures: a magnetic resonance imaging analysis of 103 patients. J Orthop Trauma. 2005 Feb;19(2):79–84. 6. Warner SJ, Garner MR, Schottel PC, Fabricant PD, Thacher RR, Loftus ML, Helfet DL, Lorich DG. The effect of soft tissue injuries on clinical outcomes after

tibial plateau fracture fixation. J Orthop Trauma. 2018 Mar;32(3):141–7. 7. Kim JG, Lim HC, Kim HJ, Hwang MH, Yoon YC, Oh JK.  Delayed detection of clinically significant posterior cruciate ligament injury after peri-articular fracture around the knee of 448 patients. Arch Orthop Trauma Surg. 2012;132:1741–6. 8. Aderinto J, Walmsley P, Keating JF.  Fractures of the tibial spine: epidemiology and outcome. Knee. 2008;15:164–7. 9. Hooper PO, Silko C, Malcolm TL, Farrow LD. Management of posterior cruciate ligament tibial avulsion injuries a systematic review. Am J Sports Med. 2018;46(3):734–42. 10. Shaikh H, Herbst E, Rahnemai-Azar AA, Albers MBV, Naendrup JH, Musahl V, Irrgang JJ.  The Segond fracture is an avulsion of the anterolateral complex. AJSM. 2017;45(10):2247–52. 11. Gaunder CL, Bastrom T, Pennock AT.  Segond fractures are not a risk factor for anterior cruciate ligament reconstruction failure. AJSM. 2017;45(14):3210–5. 12. Hall FM, Hochman MG.  Medial Segond-type fracture: cortical avulsion off the medial tibial plateau associated with tears of the posterior cruciate ligament and medial meniscus. Skelet Radiol. 1997 Sep;26(9):553–5. 13. Kose O, Ozyurek S, Turan A, Guler F.  Reverse Segond fracture and associated knee injuries: a case

21  Management of Ligament Injuries Following Fractures Around the Knee report and review of 13 published cases. Acta Orthop Traumatol Turc. 2016;50:587–91. 14. Sugita T, Onuma M, Kawamata T, Umehara J.  Injuries to the posterolateral aspect of the knee accompanied by compression fracture of the anterior part of the medial tibial plateau Takeshi Chiba, M.D. Arthroscopy. 2001;17(6):642–7. 15. Tomás-Hernándeza J, Monyartb JM, Serraa JT, Vinaixab MR, Farfana EG, Garcíaa VM, Feliub EC.  Large fracture of the anteromedial tibial plateau with isolated posterolateral knee corner injury: case series of an often missed unusual injury pattern. Injury. 2016 Sep;47(Suppl 3):S35–40. 16. Abdel-Hamid MZ, Chang CH, Chan YS, Lo YP, Huang JW, Hsu KY, Wang CJ. Arthroscopic evaluation of soft tissue injuries in tibial plateau fractures: retrospective analysis of 98 cases. Arthroscopy. 2006, June;22(6):669–75. 17. Wang J, Wei J, Wang M. The distinct prediction standards for radiological assessments associated with soft tissue injuries in the acute tibial plateau fracture. Eur J Orthop Surg Traumatol. 2015;25:913–20.

221

18. Kolb JP, Regier M, Vettorazzi E, Stiel N, Petersen JP, Behzadi C, Rueger JM, Spiro AS. Prediction of meniscal and ligamentous injuries in lateral tibial plateau fractures based on measurements of lateral plateau widening on multidetector computed tomography scans. Biomed Res Int. 2018 Jul 29;2018:5353820. 19. Pellegrini A.  Traumatic calcification of the collat eral tibial ligament of the left knee joint. Clin Med. 1905;11:433–9. 20. Stieda A.  Uber eine typische verletzung am unteren femurende. Arch F Klin Chir. 1908;85:815. 21. Chahla J, Moatshe G, Dean CS, LaPrade RF.  Posterolateral corner of the knee: current concepts. Arch Bone Joint Surg. 2016;4(2):97–103. 22. Chahla J, Murray IR, Robinson J, et al. Posterolateral corner of the knee: an expert consensus statement on diagnosis, classification, treatment, and rehabilitation. Knee Surg Sports Traumatol Arthrosc. 2019;27:2520–9.

Management of Chondral Injuries Following Fractures Around the Knee

22

Johannes Zellner, Matthias Koch, Johannes Weber, and Peter Angele

Fractures around the knee joint are able to impair the articular cartilage in various manners. Chondral injuries directly related to knee fractures with an intraarticular involvement (e.g., multifragmentary cartilaginous defect areas, osteochondral fragments, or osteochondral steps) are cartilage lesions, which are diagnosed and need to be treated in the course of the osteosynthesis. In addition to the trauma-associated chondral injuries mentioned above, there are direct impacts to the cartilage as part of the injury mechanism without any initial macroscopically defect zone. In those cases, cartilage damage and defect size are mostly noticed over time. Thus, cartilage therapy has to be performed at a later time. Furthermore, knee-associated fractures can cause a malalignment as well as ligamentary joint instability, which both consecutively injure the chondral surface over time. Thus, a complete diagnostic concerning the extent of fracture and chondral lesions as well as joint stability and alignment is required for the planning of cartilage therapy following fractures around the knee joint. J. Zellner (*) · P. Angele Department of Trauma Surgery, University Medical Center of Regensburg, Regensburg, Germany Sporthopaedicum Regensburg, Regensburg, Germany e-mail: [email protected] M. Koch · J. Weber Department of Trauma Surgery, University Medical Center of Regensburg, Regensburg, Germany

Whereas osteochondral steps have to be reduced and treated in the course of knee fracture reduction and osteosynthesis, osteochondral fragments as well as isolated cartilage lesions need an adapted management according to the published guideline by the working group “Tissue Regeneration” of the German Society of Orthopaedic Surgery and Traumatology [1].

22.1 Management of Osteochondral Fractures Osteochondral fractures are a special entity of chondral injuries and are typically associated with fractures around the knee joint [2, 3]. These fractures have to be distinguished against isolated chondral lesions without involvement of the subchondral bone and osteochondral lesions, such as osteochondrosis dissecans (OD) or Ahlback disease, which are basically characterized by a non-­ traumatic history as well as necrosis and sclerosis of the subchondral bone [2, 3]. The typical history of osteochondral fractures is a joint distortion including a direct trauma to the cartilage and subchondral bone [3]. In the course of a rotational and/or impact load, these traumas may result in shear-induced injuries as well as osteochondral fragment depression injuries in the periphery of the knee joint [2, 3]. The injurious effect is typically accompanied with an abrupt loss of stability and incongruity of the

© Springer Nature Switzerland AG 2021 M. Hanschen et al. (eds.), Knee Fractures, Strategies in Fracture Treatments, https://doi.org/10.1007/978-3-030-81776-3_22

223

224

articular surface [2]. Thus, the rate of associated ligamentary injuries, like injuries of the anterior cruciate ligament (ACL) or collateral ligaments, is high [2, 4]. One further characteristic injury mechanism is the patella luxation and subluxation [3, 5]. Thereby osteochondral fractures are typically observed in the area of the lateral femoral condyle as well as at the retropatellar articular surface [3]. Isolated and small chondral fragments tend to be resorbed over the time and can be treated conservatively as long as they do not cause blocking symptoms. In contrast, osteochondral fragments generally have to be treated by an operative restoration of the congruence of the articular surface [2]. According to the current literature, there are different treatment options for the therapy of osteochondral fractures. However, literature lacks of good evidence and long-term results, so there is no consensus concerning the optimal therapy [2, 6]. According to Kühle et  al., refixation of the osteochondral fragment should be the aim of each osteochondral fracture therapy [2]. The only exceptions can be: • Defect areas out of the load-bearing area, for example, an osteochondral impression fracture at the anterolateral femoral condyle after ACL rupture • Osteochondral fractures with a defect size 5 mm (b); type III fractures have an unstable prothesis regardless of the degree of dislocation

external fixators. Therefore, external fixators should be considered rather as a temporary option, i.e. in complex periprosthetic fractures that might require special implant replacement. The Rorabeck and Taylor classification (Fig. 23.2) has proven its usefulness for decision-­ making in patients presenting with a fracture in the area of a knee arthroplasty [26]. The average age of patients with a periprosthetic distal femur fracture is 76  years, and the 3-year mortality of such patients is high [27]. These patients are often already significantly limited in their mobility before their fall. This makes sufficient postoperative mobilization difficult. The fracture morphology is decisive for the surgical treatment strategy, while the key question is to rule out if the prosthesis is stable or loosened. In the case of fractures with a stable prosthesis (Rorabeck type I or II), the prosthesis can be left in place, and osteosynthesis can be performed. In the case of Rorabeck type III fractures, the prosthesis must be replaced in addition to fracture stabilization. For adequate preoperative plan-

c

(c). Figure from: Gassner, C., Sommer, F., Rubenbauer, B. et al. Winkelstabile Plattenosteosynthese bei distalen periprothetischen Femurfrakturen. Unfallchirurg (2020). https://doi.org/10.1007/s00113-­020-­00911-­6

23  Challenges in Geriatric Patients with Fractures Around the Knee

ning, it is therefore essential to have precise imaging, ideally a CT scan, as well as exact knowledge of the inserted prosthesis. Even with a total knee arthroplasty in place, retrograde intramedullary nailing is possible if the prosthesis design is appropriate (open-box design). A major advantage of intramedullary nailing is the maximum soft tissue protection when closed reduction is possible and improved mechanical stability [28, 29]. Complex fractures often show small fragments, and thus secure fixation of the nail is not possible, so it is necessary to use a plate. Various plate systems are available for treatment with plate osteosynthesis. Here, some implants offer polyaxial screw insertion which has the advantage of increasing stability and avoiding contact with the prothesis (e.g. Zimmer® NCB; DePuy Synthes® LISS, VA-LCP). In addition to classical implantation, these implants can also be inserted minimally invasively by using a mini-open approach to reduce soft tissue damage. In cases of massive osteoporosis of the distal femur, secure screw fixation is often not guaranteed. In this case, additive cement augmentation of the plate osteosynthesis over the condylar screw can provide increased stability [30]. If it is necessary to change the knee arthroplasty, revision implants usually have to be used. These have long anchoring stems to ensure sufficient stability, especially in inferior, osteoporotic bone. Particularly in the case of an already inserted medullary joint or a total hip prosthesis, strict care must be taken to ensure that there is no contact with the implant (kissing implants), and thus a biomechanical stress riser should be avoided. Ideally, implants should be at least 3 cm apart from each other [31].

23.5.2 Proximal Tibial Fractures Proximal tibial fractures in geriatric patients follow the same aetiology as distal femoral fractures. Also in these patients, poor bone quality and low-energy trauma are very common. Due to the increasing amount of patients presenting with

239

knee prosthesis and the demographic changes of our ageing population, the incidence of periprosthetic tibial fractures is also increasing and occurs in 0.4–1.7% of implanted knee arthroplasties [32]. These can occur intraoperatively, especially during the preparation and implantation of a prosthesis stem, and in the further course due to a fall event or a fatigue fracture. The aim of treatment is rapid and complete mobilization of the often geriatric patients. If possible, osteosynthesis with preservation of the prosthesis and restoration of the leg axis should be carried out, whereas loosening in the area of the prosthesis requires replacement surgery. The classification of proximal tibial fractures without knee arthroplasty follows the AO/OTA classification and distinguishes extra-articular from intra-articular fractures. Conservative therapy is only possible for simple fractures without the development of a significant joint step, instability or fragment dislocation. Intra-articular concomitant injuries should be excluded, and the possibility of prompt functional follow-up should be ensured. Primary arthroplasty may be appropriate in geriatric patients to allow rapid postoperative mobilization, while the use of constrained prosthesis might be necessary in patients with insufficient ligament stability. Otherwise, single-stage principles should be applied to geriatric patients, and definitive osteosynthesis should be performed early. If there is massive soft tissue damage, a two-stage procedure with external fixators might also be necessary. Definitive osteosynthesis should be performed within the first 2 weeks. The standard procedure for fracture fixation is open reduction and internal fixation with locking plates and the use of void fillers in case of joint depression fractures. PMMA bone cement augmentation is another feasible approach to increase the bone-­ implant interface [33, 34]. However, secondary loss of reduction due to displacement of the articular surface is likely in the geriatric patient because of early full weight-bearing and poor bone quality. In this case, further reconstruction surgery with osteotomies must be well considered, and conversion to total knee arthroplasty should be preferred in many cases [35].

240

Primary fracture arthroplasty in geriatric patients with proximal tibial fracture is increasingly performed to achieve rapid mobilization. The case series published to date show inconsistent results, and results are still under discussion. However, most authors see more benefits from rapid mobilization under weight-bearing. Joint replacement for tibial plateau fractures shows better overall clinical outcomes but poorer knee score results than in patients treated with plate osteosynthesis. The results of primary joint replacement for fractures around the knee seem to have better results than those secondary after failure of internal fixation, with lower rates of complications and revision and earlier full weight-bearing [36–40]. It can be expected that numerous studies will be conducted in the near future to further investigate this controversial topic and to bring fundamental changes in therapeutic approaches.

A. M. Keppler et al.

Case Report  A 70-year-old female patient with a lateral tibial plateau compression due to a stumbling fall (Fig.  23.3). Mild osteoarthrotic complaints were already present before the fall. Therefore, a total knee arthroplasty was implanted to achieve ‘single shot’ surgery. The patient was mobilized on the first postoperative day and was able to walk pain-free after completion of rehabilitation. Tibial periprosthetic fractures can be classified into four types based on the Felix classification (Fig. 23.4); the classification is also based on the anatomical position and the stability of the implant [41]. In addition to prosthesis preservation using locking implants, prosthesis replacement may be necessary in case of loosening. Conservative therapy does not play a significant role, and early surgical therapy is warranted [42]. If there is doubt whether the prosthesis is stable

Fig. 23.3  3D CT reconstruction of a lateral tibial plateau split-compression fracture on the right. Treatment with a total knee prothesis, following the principles of ‘single shot’ surgery

23  Challenges in Geriatric Patients with Fractures Around the Knee

241

Typ I Typ IV

Typ II

Typ III

Fig. 23.4  Example illustration of the Felix classification on an a.p. and lateral plain radiograph. The course of the fracture line is decisive; a loose prosthesis is additionally marked with (stable) or (loose). Abbildung aus Hawellek,

T., Lehmann, W. & von Lewinski, G.  Periprothetische Frakturen rund um das Knie. Chirurg 91, 833–840 (2020). https://doi.org/10.1007/s00104-­020-­01212-­9

and no reliable statement can be made on the basis of older imaging, a generous indication for surgery and intraoperative examination should be made.

fracture mobility, cognition, depression, fall risk, nutritional status, incontinence and visual function is important to determine the optimal rehabilitation programme [21]. This also includes early discharge planning. Ideally, a clinic’s own social service should be involved here in order to be able to organize not only the rehabilitation but also any necessary medical aids or adjustments to the care level.

23.5.3 Postoperative Management and Rehabilitation Sufficient pain therapy is essential for rapid and safe mobilization. Attention must be paid to the various pharmacological interactions. For example, non-steroidal anti-inflammatory drugs (NSAIDs) have no place in geriatric traumatology. Opiates have been proven effective for the early postoperative phase and are available as oral and intravenous preparations. In orthogeriatric patients, it is of particular importance to start rehabilitation immediately after surgery to prevent loss of self-care and independence. This should be a particular focus, as patients are insufficiently mobilized in the hospital [43]. Especially in orthogeriatric patients, a multidisciplinary rehabilitation process is a key factor leading to optimal results of a successful surgical intervention [20]. Assessment of pre-­

23.6 Secondary Fracture Prevention Secondary fracture prevention is another key element which requires special consideration in orthogeriatric patients, as these patients are at a higher risk to suffer further osteoporosis associated fractures. Most of the geriatric patients presenting with lower extremity fractures have an underlying 25-OH vitamin D deficiency and require a basic treatment with vitamin D such as an additional specific osteoporosis therapy. In a double-blind, placebo-controlled trial, treatment with zoledronic acid compared with placebo reduced the risk of, i.e. morphometric vertebral

242

fractures by 70% during a 3-year period. These findings strengthen the need of secondary fracture prevention [44]. However, in women eligible for the treatment of osteoporosis in Germany, only 23% received appropriate treatment [1]. The implementation of a Fracture Liaison Service (FLS) that provides a standardized identification and treatment of osteoporosis in orthogeriatric patients has proven to be an effective approach for secondary fracture prevention. In 1 trial, the FLS produced a 30% reduction for any fracture and a 40% reduction for major refractures when compared to a standard approach, whereas only 20 patients needed to be treated to prevent 1 new fracture in 3 years [45]. The impact of comprehensive geriatric care on the patients’ mobility and subsequent fall prevention is also important for secondary fracture prevention in orthogeriatric patients.

References 1. Lisk R, Yeong K. Reducing mortality from hip fractures: a systematic quality improvement programme. BMJ Qual Improv Rep. 2014;3:u205006.w2103. https://doi.org/10.1136/bmjquality.u205006.w2103. 2. Khan SK, Jameson SS, Avery PJ, Gray AC, Deehan DJ. Does the timing of presentation of neck of femur fractures affect the outcome of surgical intervention. Eur J Emerg Med. 2013;20:178–81. https://doi. org/10.1097/MEJ.0b013e328354aee5. 3. Juliebø V, Bjøro K, Krogseth M, Skovlund E, Ranhoff AH, Wyller TB.  Risk factors for preoperative and postoperative delirium in elderly patients with hip fracture. J Am Geriatr Soc. 2009;57:1354–61. https:// doi.org/10.1111/j.1532-­5415.2009.02377.x. 4. Lee KH, Ha YC, Lee YK, Kang H, Koo KH. Frequency, risk factors, and prognosis of prolonged delirium in elderly patients after hip fracture surgery. Clin Orthop Relat Res. 2011;469:2612–20. https://doi. org/10.1007/s11999-­011-­1806-­1. 5. Murphy C, Mullen E, Hogan K, O’toole R, Teeling SP. Streamlining an existing hip fracture patient pathway in an acute tertiary adult Irish hospital to improve patient experience and outcomes. Int J Qual Health Care. 2019;31:45–51. https://doi.org/10.1093/intqhc/ mzz093. 6. Luger TJ, Kammerlander C, Luger MF, Kammerlander-­ Knauer U, Gosch M. Anästhesieverfahren, Mortalität und Verlauf bei geriatrischen Patienten. Zeitschrift fur Gerontologie und Geriatrie. 2014;47:110–24.

A. M. Keppler et al. 7. Inouye SK.  Delirium in older persons. N Engl J Med. 2006;354:1157–65. https://doi.org/10.1056/ nejmra052321. 8. Gosch M, Nicholas JA. Pharmakologische Prävention des postoperativen Delirs. Zeitschrift fur Gerontologie und Geriatrie. 2014;47:105–9. 9. Mendelson DA, Friedman SM. Principles of comanagement and the geriatric fracture center. Clin Geriatr Med. 2014;30:183–9. 10. Bonaiuti D, Shea B, Iovine R, Negrini S, Welch V, Kemper HH, Wells GA, Tugwell P, Cranney A. Exercise for preventing and treating osteoporosis in postmenopausal women. In: Cochrane database of systematic reviews. New York: Wiley; 2002. 11. Huuskonen J, Väisänen SB, Kröger H, Jurvelin JS, Alhava E, Rauramaa R.  Regular physical exercise and bone mineral density: a four-year controlled randomized trial in middle-aged men. The DNASCO study. Osteoporos Int. 2001;12:349–55. https://doi. org/10.1007/s001980170101. 12. Willburger RE, Knorth H. Osteoporose der Wirbelsäule: Therapieoption und Präventionsstrategien. Dtsch Arztebl Int. 2003;100:A-1120. 13. Kammerlander C, Pfeufer D, Lisitano LA, Mehaffey S, Böcker W, Neuerburg C.  Inability of older adult patients with hip fracture to maintain postoperative weight-bearing restrictions. J Bone Joint Surg. 2018;100:936–41. https://doi.org/10.2106/ JBJS.17.01222. 14. Siu AL, Penrod JD, Boockvar KS, Koval K, Strauss E, Morrison RS.  Early ambulation after hip fracture. Arch Intern Med. 2006;166:766. https://doi. org/10.1001/archinte.166.7.766. 15. Hill K.  Additional physiotherapy during acute care reduces falls in the first 12 months after hip fracture. J Physiother. 2010;56:201. 16. Ottesen TD, McLynn RP, Galivanche AR, Bagi PS, Zogg CK, Rubin LE, Grauer JN.  Increased complications in geriatric patients with a fracture of the hip whose postoperative weight-bearing is restricted: an analysis of 4918 patients. Bone Joint J. 2018;100B:1377–84. https://doi.org/10.1302/0301-­ 620X.100B10.BJJ-­2018-­0489.R1. 17. Ogilvie-Harris DJ, Botsford DJ, Hawker RW. Elderly patients with hip fractures: Improved outcome with the use of care maps with high-quality medical and nursing protocols. J Orthop Trauma. 1993;7:428–37. https://doi.org/10.1097/00005131-­199310000-­00005. 18. Cameron ID, Chen JS, March LM, Simpson JM, Cumming RG, Seibel MJ, Sambrook PN.  Hip fracture causes excess mortality owing to cardiovascular and infectious disease in institutionalized older people: a prospective 5-year study. J Bone Miner Res. 2010;25:866–72. https://doi.org/10.1359/ jbmr.091029. 19. Roche JJW, Wenn RT, Sahota O, Moran CG.  Effect of comorbidities and postoperative complications on mortality after hip fracture in elderly people: prospective observational cohort study. Br

23  Challenges in Geriatric Patients with Fractures Around the Knee Med J. 2005;331:1374–6. https://doi.org/10.1136/ bmj.38643.663843.55. 20. Mohanty S, Rosenthal RA, Russell MM, Neuman MD, Ko CY, Esnaola NF. Optimal perioperative management of the geriatric patient: a best practices guideline from the American College of Surgeons NSQIP and the American Geriatrics Society. J Am Coll Surg. 2016;222:930–47. https://doi.org/10.1016/j. jamcollsurg.2015.12.026. 21. Ftouh S, Morga A, Swift C. Management of hip fracture in adults: summary of NICE guidance. BMJ. 2011;342:d3304. 22. Maegele M, Grottke O, Schöchl H, Sakowitz O, Spannagl M, Koscielny J.  Direkte orale Antikoagulanzien in der traumatologischen Notaufnahme  – Perioperative Behandlung und Umgang in Blutungssituationen. Deutsches Arzteblatt Int. 2016;113:575–82. 23. Nowak H, Unterberg M.  Orale Antikoagulanzien: management von elektiven und Notfalleingriffen TT  – oral anticoagulants: management of elective and emergency surgery. Anästhesiol Intensivmed Notfallmed Schmerzther. 2018;53:543–50. 24. Court-Brown CM, Caesar B.  Epidemiology of adult fractures: a review. Injury. 2006;37:691–7. https://doi. org/10.1016/j.injury.2006.04.130. 25. Bae DK, Song SJ, Yoon KH, Kim TY. Periprosthetic supracondylar femoral fractures above total knee arthroplasty: comparison of the locking and non-­ locking plating methods. Knee Surg Sports Traumatol Arthrosc. 2014;22:2690–7. https://doi.org/10.1007/ s00167-­013-­2572-­2. 26. Rorabeck CH, Taylor JW. Classification of periprosthetic fractures complicating total knee arthroplasty. Orthop Clin N Am. 1999;30:209–14. https://doi. org/10.1016/S0030-­5898(05)70075-­4. 27. Gassner C, Sommer F, Rubenbauer B, Keppler AM, Liesaus Y, Prall WC, Kammerlander C, Böcker W, Fürmetz J.  Locking plate fixation of distal periprosthetic femoral fractures: clinical outcome and mortality. Unfallchirurg. 2020:1–7. https://doi.org/10.1007/ s00113-­020-­00911-­6. 28. Schitz F, Rilk S, Schabus R.  Arthroscopic treat ment of a supracondylar femoral fracture with total knee arthroplasty and retrograde femoral nailing. Arthroskopie. 2020;34:74–9. 29. Pekmezci M, McDonald E, Buckley J, Kandemir U. Retrograde intramedullary nails with distal screws locked to the nail have higher fatigue strength than locking plates in the treatment of supracondylar femoral fractures: a cadaver-based laboratory investigation. Bone Joint J. 2014;96(B):114–21. https://doi. org/10.1302/0301-­620X.96B1.31135. 30. Wähnert D, Hofmann-Fliri L, Richards RG, Gueorguiev B, Raschke MJ, Windolf M.  Implant augmentation: adding bone cement to improve the treatment of osteoporotic distal femur fractures: a biomechanical study using human cadaver bones.

243

Medicine (United States). 2014;93. https://doi. org/10.1097/MD.0000000000000166. 31. Harris T, Ruth JT, Szivek J, Haywood B. The effect of implant overlap on the mechanical properties of the femur. J Trauma. 2003;52:930–5. https://doi. org/10.1097/01.TA.0000060999.54287.39. 32. Agarwal S, Sharma RK, Jain JK.  Periprosthetic fractures after total knee arthroplasty. J Orthop Surg (Hong Kong). 2014;22:24–9. https://doi. org/10.1177/230949901402200108. 33. Kammerlander C, Neuerburg C, Verlaan JJ, Schmoelz W, Miclau T, Larsson S.  The use of augmentation techniques in osteoporotic fracture fixation. Injury. 2016;47:S36–43. https://doi.org/10.1016/ S0020-­1383(16)47007-­5. 34. Larsson S.  Cement augmentation in fracture treatment. Scand J Surg. 2006;95:111–8. 35. Raschke M, Zantop T, Petersen W. Tibiakopffraktur. Chirurg. 2007;78:1157–71. https://doi.org/10.1007/ s00104-­007-­1428-­z. 36. Parratte S, Ollivier M, Argenson JN.  Primary total knee arthroplasty for acute fracture around the knee. Orthopaed Traumatol Surg Res. 2018; 104:S71–80. 37. Wong MT, Bourget-Murray J, Johnston K, Desy NM. Understanding the role of total knee arthroplasty for primary treatment of tibial plateau fracture: a systematic review of the literature. J Orthop Traumatol. 2020;21 38. Sabatini L, Aprato A, Camazzola D, Bistolfi A, Capella M, Massè A. Primary total knee arthroplasty in tibial plateau fractures: Literature review and our institutional experience. Injury. 2021. https://doi. org/10.1016/j.injury.2021.02.006. 39. Scott CEH, Davidson E, Macdonald DJ, White TO, Keating JF.  Total knee arthroplasty following tibial plateau fracture: a matched cohort study. Bone Joint J. 2015;97-B:532–8. https://doi. org/10.1302/0301-­620X.97B4.34789. 40. Tapper V, Toom A, Pesola M, Pamilo K, Paloneva J.  Knee joint replacement as primary treatment for proximal tibial fractures: analysis of clinical results of twenty-two patients with mean follow-up of nineteen months. Int Orthop. 2020;44:85–93. https://doi. org/10.1007/s00264-­019-­04415-­w. 41. Felix NA, Stuart MJ, Hanssen AD.  Periprosthetic fractures of the tibia associated with total knee arthroplasty. In: Clinical orthopaedics and related research. New York: Springer; 1997. p. 113–24. 42. Ruchholtz S, Tomás J, Gebhard F, Larsen MS. Periprosthetic fractures around the knee-the best way of treatment. Eur Orthop Traumatol. 2013;4:93– 102. https://doi.org/10.1007/s12570-­012-­0130-­x. 43. Keppler AM, Holzschuh J, Pfeufer D, Neuerburg C, Kammerlander C, Böcker W, Fürmetz J. Postoperative physical activity in orthogeriatric patients  – new insights with continuous monitoring. Injury. 2020. https://doi.org/10.1016/j.injury.2020.01.041.

244 44. Liem IS, Kammerlander C, Suhm N, Blauth M, Roth T, Gosch M, Hoang-Kim A, Mendelson D, Zuckerman J, Leung F, Burton J, Moran C, Parker M, Giusti A, Pioli G, Goldhahn J, Kates SL. Identifying a standard set of outcome parameters for the evaluation of orthogeriatric co-management for hip fractures. Injury. 2013;44:1403–12.

A. M. Keppler et al. 45. Nakayama A, Major G, Holliday E, Attia J, Bogduk N.  Evidence of effectiveness of a fracture liaison service to reduce the re-fracture rate. Osteoporos Int. 2016;27:873–9. https://doi.org/10.1007/ s00198-­015-­3443-­0.

Juvenile Fractures Around the Knee

24

Hamzah Alhamzah, Jimmy Tat, Jong Min Lee, and David Wasserstein

24.1 D  istal Femoral Physeal/ Epiphyseal Fractures 24.1.1 Epidemiology Distal femoral physeal/epiphyseal fracture is an uncommon injury, estimated to account for between 1.4 and 2% of all paediatric physeal injuries [1]. However, they often have significant sequelae. On average, growth disturbance occurs in more than half of these patients, with higher chances in displaced fractures and lower in non-­ displaced fractures [2]. When categorized using the Salter-Harris classification, the highest incidence of growth disturbance is in SH IV fractures (65%) and lowest SH I (35%) [2]. At a younger age, the mechanism of injury is more often high-energy trauma, such as motor vehicle accidents, whereas sports-related injuries cause distal femoral physeal fractures in adolescence. Significant trauma is thought to be H. Alhamzah Department of Orthopaedic Surgery, College of Medicine, King Saud University, Riyadh, Saudi Arabia J. Tat · J. M. Lee Division of Orthopaedic Surgery, Toronto, ON, Canada D. Wasserstein (*) Sunnybrook Health Sciences Centre, Toronto, ON, Canada Division of Orthopaedic Surgery, Toronto, ON, Canada e-mail: [email protected]

required to disrupt the thick periosteum and perichondrium in order to cause displacement in younger juvenile patients, in comparison to adolescent patients that have thinner periosteum [3].

24.1.2 Classification, Associated Injuries and Workup Distal femur physeal fractures in the juvenile population occur when there are an open distal femur physis and a force that produces a valgus stress or hyperextension at the knee. This can be associated with a direct blow, but more often, awkward landing mechanics from a jump or fall from a height. In the juvenile population, the distal femur physis is the weak link in the knee joint, compared to the ligamentous knee structures, and thus fractures often involve the physis [4].

24.1.2.1 Classification Distal femur physeal fractures can be described using the Salter-Harris classification [4]. • Type I: fracture is a separation through the physis. • Type II: fracture enters in the plane of the physis and exits through the metaphysis. The resulting metaphyseal fragment is called the Thurstan Holland fragment. Depending on the mechanism (varus or valgus load), the perios-

© Springer Nature Switzerland AG 2021 M. Hanschen et al. (eds.), Knee Fractures, Strategies in Fracture Treatments, https://doi.org/10.1007/978-3-030-81776-3_24

245

H. Alhamzah et al.

246

teum on the tension side of the physis fails and results in the metaphyseal side failure due to compression. • Type III: fracture enters in the plane of the physis and exits through the epiphysis. • Type IV: fracture crosses the physis, extending from the metaphysis to the epiphysis. • Type V: fracture is a crush injury resulting in injury to the physis (Figure) [5].

Type I

Type II

For many physeal fractures in other anatomic sites, risk of growth disturbance is smaller with type I and II fractures and higher with types III and IV.  While the same pattern generally holds for distal femoral physeal fractures, there is a significant growth disturbance risk regardless of type. This classification scheme is useful for treatment planning and is also a good indicator of the mechanism of injury [6].

Type III

Type IV

Type V

Salter-Harris classification of epiphyseal fractures. Type I fractures involve a fracture line that only traverses the physis. When the fracture line traverses the growth plate and exits obliquely through the metaphysis, it is a type II fracture, while exiting through the epiphysis towards the joint is type III. Type IV fractures have a vertical split of the epiphysis, physis and metaphysis. Type V fractures involve a crush injury to the physeal plate. (Edwards 1995 – Adapted from JAAOS – Journal of the American Academy of Orthopaedic Surgeons 3(2):63–69, March–April 1995 [7])

24.1.2.2 Associated Injury Distal femur fractures are typically a result of a high-energy mechanism of injury, and a thorough trauma assessment should be completed with Advanced Trauma Life Support (ATLS) protocols [8, 9]. The most common associated injuries with distal femur physeal fractures are other musculoskeletal injuries, of which knee ligament injuries are the most common [8]. In a retrospective review of 151 cases [10], ligamentous laxity of the knee was clinically evident in 21 patients (13.9%), of which 12 patients (7.9%) had symptomatic instability. Other rare complications include compartment syndrome (1.3%), popliteal artery injury and peroneal nerve injury [10]. Therefore, a detailed neurovascular exam should be documented for every patient. The popliteal artery is usually injured in hyperextension-type knee injuries, where the apex posterior deformity brings the distal metaphysis of the femur posteriorly and causes

direct pressure to the popliteal vessels resulting in laceration, intimal tear or thrombosis [6]. The risk of peroneal nerve injury is present, but most often a neuropraxia with good prognosis and expected recovery within 6 to 12 weeks [11].

24.1.2.3 Signs and Symptoms Patients with a distal femoral physeal/epiphyseal fracture usually present with knee joint effusion, local soft tissue swelling and tenderness over the physis. In displaced injuries, deformity may be evident, and soft or muffled crepitus with motion often can be felt. In the anteriorly displaced epiphysis (i.e. apex posterior), the patella becomes prominent, and the anterior skin is often dimpled. These are usually associated with high-­ energy hyperextension injury and have an increased risk of neurovascular compromise as noted. With posterior displacement of the epiphysis (i.e. apex anterior),

24  Juvenile Fractures Around the Knee

the distal metaphyseal fragment becomes prominent just above the patella [12]. Although vascular injuries are rare after fractures of the distal femoral physis, the vascular status must also be evaluated carefully [6].

24.1.2.4 Imaging Radiographs  Anteroposterior and lateral radiographs should routinely be obtained to evaluate the displacement of the fractures. Oblique radiographs may help reveal minimally displaced fractures. Gentle stress radiographs can help differentiate a physeal separation from a ligamentous injury in a patient who has pain and apparent laxity of the knee and whose plain radiographs fail to reveal a fracture. Adequate analgesia can alleviate muscle spasm and protect the physis from further damage during the examination [12]. Computed Tomography (CT)  CT is recommended for all patients with Salter-Harris III and IV fractures diagnosed on plain radiographs. In one study, CT identified fracture displacement and comminution that was not recognized on plain radiographs of the knee. The authors encouraged its use for evaluation of these fractures to identify displacement, define fracture geometry and plan surgical fixation. CT may also be useful to identify fractures and displacement in cases where the plain radiographs are inconclusive, but the examination is suspicious for a distal femoral physeal fracture [6].

Magnetic Resonance Imaging (MRI)  The primary utility of MRI is to identify acute knee injuries when the examination and radiographs are non-diagnostic or equivocal. MRI is also effectively utilized to determine the viability of the physis after healing of a traumatic injury. The recommended sequence is fat-suppressed three-­ dimensional spoiled gradient-recalled echo sequence. This MRI sequence can identify early impending growth disturbance and can be used to map the extent of physeal bony bar formation to determine if excision is an option for treatment [6].

247

24.1.3 Treatment The principle of treatment is to achieve and maintain anatomic reduction of the fracture without further compromising the physis [6]. Non-operative treatment with long leg casting is generally reserved for non-displaced distal femoral physeal fractures [6, 13]. Close reduction manoeuvres should be performed under general anaesthesia with 90% traction and 10% manipulation to achieve anatomic reduction [6, 14]. This method is thought to reduce further physeal injury. Close follow-up is required to monitor for any fracture displacement [13, 14], especially with displaced fractures as current literature suggests up to 70% failure with only closed reduction and long leg casting [15]. Alternatively, displaced fractures usually warrant operative management [6]. Operative management includes closed vs open reduction and internal fixation utilizing smooth Kirschner wires or screws [3, 13, 16]. Displaced Salter-Harris I and II fractures are generally treated with closed reduction and percutaneous fixation, with either physeal-traversing smooth pins or physeal-sparing screws [3, 6, 16]. However, some SH II fractures with interposed periosteum require an open reduction. Pre-­operative MRI can help identify periosteal entrapment preventing anatomic reduction of fracture [17]. A case series by Garrett et al. [3] showed no significant increase in physeal bar formation with the use of smooth Kirschner wires across the physis in Salter-Harris type I and II fractures, and a study by Mäkelä et  al. [18] demonstrated no significant risk of permanent physeal arrest when small pins 70%) of fractures occur during athletic activities that require jumping, such as basketball [35]. There is a possible relationship between Osgood-

H. Alhamzah et al.

Schlatter’s condition and tubercle avulsion fracture; however, no clear scientific cause-effect has been established [35].

24.3.2 Classification, Associated Injuries and Workup 24.3.2.1 Classification The most commonly used classification of tibial tubercle fractures is the Ogden modification of the original Watson-Jones classification. In the original Watson-Jones article [36], they described three types of fractures. The first type described an avulsion fracture of the most distal portion of the ossification centre of the tuberosity. The second was an upward angulation of the entire tuberosity at the level of the proximal tibial physis and junction of the ossification centres of the tuberosity and proximal end of the tibia. In the third, the fracture line of the tuberosity physis propagated into the main tibial epiphysis, avulsing a large, anterior, single fragment. However, it did not account for the possibility of intra-articular extension. Thus, the modified classification scheme from Ogden added two subtypes according to the severity of displacement and comminution to include the possibility of intra-articular extension of the fracture and comminution of the tuberosity. The Ogden modification types include: • Type IA fractures are distal to the junction between the proximal tibia and the apophysis and are non-displaced or minimally displaced. • Type IB fractures are hinged in this location. • Type IIA fractures are at the junction of the proximal tibia and tubercle. • Type IIB fractures are comminuted with anterior translation of the distal fragment. • Type IIIA fractures extend into the articular surface. • Type IIIB fractures are intra-articular and comminuted [34].

24  Juvenile Fractures Around the Knee

253

1A

1B

2A

2B

3A

3B

Figure of modified Ogden classification (Ogden 1980) [34]

H. Alhamzah et al.

254

In 1985, Ryu and Debenham additionally suggested a type IV which is a fracture of the tibial tuberosity that extends posteriorly through the proximal tibial physis creating an avulsion of the entire proximal epiphysis [37]. Finally, McKoy and Stanitski in 2003 proposed a type V which consists of a type IIIB fracture with an associated type IV fracture creating a “Y” configuration [38]. The final most commonly used classification as recommended by most authors is the ­modified Ogden classification that includes both updated types IV and V.

1

2

• Type I: Apophyseal injuries at the patellar tendon insertion (A, displaced; B, non-displaced) • Type II: Apophyseal/epiphyseal injuries without intra-articular extension (A, displaced; B, non-displaced) • Type III: Apophyseal/epiphyseal injuries with intra-articular extension (A, displaced; B, non-displaced) • Type IV: Fracture of the entire proximal tibia, +/− posterior Thurstan Holland fragment (A, displaced; B, non-displaced) • Type V: No fracture, pure avulsion injury of the patellar tendon

3

4

5

Modified Ogden classification—Rockwood and Green in Fractures in Children [6]

24.3.2.2 Associated Injuries The mechanism of injury for tibial tubercle fractures is usually in the setting of a sporting event with a jump or forced knee flexion and a strong eccentric contraction from the quadriceps. Other knee injuries may occur in association with tubercle avulsion fractures and include collateral ligament, meniscal and anterior cruciate ligament disruption [35]. Stanitski [35] reported a 17% incidence of associated injury to other parts of the extensor mechanism (quadriceps and patellar tendon disruption). These were mostly associated with type IIB and IIIB injuries. Additionally, it should be noted that the anterior tibial recurrent artery, which resides in the anterior compartment near the tibia tubercle, is frequently disrupted with this injury. This can lead to bleeding and compressive injury of the artery and deep peroneal nerve or compartment syndrome [39]. Therefore, serial neurovascular examination is

warranted, with special attention to the anterior compartment structures. Tibial tubercle apophyseal fractures are more frequently the result of jumping activities, with the two most common mechanisms reported being (1) a strong quadriceps contraction during knee extension associated with jumping and (2) rapid passive flexion of the knee against the contracting quadriceps while landing. Moreover, tibial tuberosity fractures are reported almost exclusively in adolescent boys who tend to have greater quadriceps strength and may overcome the stability of the apophysis with a violent contraction of the muscle. Because the proximal tibial physis closes from posterior to anterior, the fracture pattern depends on the amount of physeal closure present at the time of injury, as well as the degree of knee flexion. When the injury occurs with the knee between 0 and 30 degrees of flexion, avulsion of the tibial tubercle without

24  Juvenile Fractures Around the Knee

fracture of the epiphysis will result; with greater than 30 degrees of flexion, avulsion of both the tibial tubercle and proximal tibial epiphysis is more likely, and so the majority are type III [6].

24.3.2.3 Imaging Radiographs  The standard method of identifying tibial tubercle fractures is via the lateral plain radiograph; however, more severe injuries should warrant advanced diagnostic imaging to help identify articular disruption and internal derangement that is often seen in these fracture patterns. Although most patients with tibial tubercle fractures are adolescents (with developed secondary ossification of the tibial tubercle), fractures may occur in the more immature child and be seen merely as a small fleck of bone on plain film [6]. Accurate lateral radiographs of the tubercle are essential to evaluate this injury. Because the tubercle is just lateral to the midline of the tibia, the best profile is obtained with the leg in slight internal rotation. Oblique radiographs of the proximal end of the tibia are helpful to visualize fully the extension of the fracture into the knee joint [12]. Minimizing use of CT scans due to radiation exposure is ideal.

24.3.3 Treatment The principles of treatment are to achieve anatomic reduction of the displaced fragments and preserve the extensor mechanism [40, 41]. Non-displaced fractures and Ogden type I and type II fractures with minimal displacement following closed reduction are treated with a splint, cylinder cast or long leg cast in full knee extension for 4–6 weeks [34, 38, 40, 41]. The timing of when to initiate active extension is controversial; however, in general, children heal faster and are less subject to complications such as stiffness when compared to adults with similar injuries. A practical approach centred around pain control is preferred. The majority of displaced fractures require operative management with open reduction and internal fixation, combined with possible repair of soft tissues [42]. Cannulated screw fixation is

255

shown to provide better compression and rigid fixation compared to percutaneous pinning [42]. Periosteal suture fixation of the fragment may be considered in very skeletally immature patients or those with significant comminution [40]. Intra-articular fracture necessitates anatomic reduction of the articular surface and repair of any associated intra-articular pathology via arthroscopic or using a mini-open medial parapatellar approach [13, 38]. Pretell-Mazzini et al. [42] found in a systematic review of these fractures that surgical treatment of most adolescent tibial tubercle fractures results in good outcomes. The most common complications were hardware irritation (56%), tibial tubercle tenderness (18%), re-fracture (6%) and recurvatum (4%). The poorest outcomes following operative management were seen in patients with both an intra-articular fracture and soft tissue injury.

24.3.4 Effect on Growth Tibial tubercle fractures are physeal injuries and can influence growth. Knowledge of the growth pattern in the proximal tibia therefore is helpful to better understand the potential complication of growth disturbance. The development of the tibial tubercle was defined by Ehrenborg [43]. The proximal tibia has two ossification centres: (1) the primary ossification centre is the proximal tibial physis and (2) the secondary is the tibial tubercle physis at the insertion of the patellar tendon. The secondary physis persists until the age of 8–12 years in females and 9–14 years in boys [43, 44]. The normal ossification pattern also involves proximal tibia physeal closure from the posterior to anterior, followed last by the tibial tubercle [45]. This therefore places the distal secondary centre at greatest risk of injury in older children as they approach the juvenile and adolescent years. The energy of injury, and accordingly the fracture pattern, typically goes through the open physis, as the weak link, rather than the region with complete ossification. Overall, patients with tibial tubercles fractures have an excellent prognosis. They have high rate

256

of fracture union and return to sports. One study reported complete consolidation in 99% of cases, with 98% of patients returning to normal activities in an average of 29 weeks and full range of motion achieved in 97% of patients [42]. Complications associated with growth arrest, deformity and leg length discrepancy are uncommon because these fractures tend to occur in older children and adolescents and at this time the proximal tibial epiphysis has ossified [12]. Genu recurvatum is a rare complication and occurs in less than 4% of cases [42], most likely due to partial growth arrest of the proximal tibia physis, and may require further intervention.

24.4 Tibial Spine/Eminence Fractures 24.4.1 Epidemiology Tibial spine fractures occur at a rate of 3 per 100,000/year [46]). In the paediatric population, they represent 2% of traumatic knee effusions [47]. They most commonly occur between the ages of 8 and 14 years due to the pull of the ACL [27]. Historically, the mechanism of injury is a forceful hyperextension of the knee (such as fall from a bicycle or motorbike) or a direct blow on the distal femur with a flexed knee [27]. However,

H. Alhamzah et al.

recent reports have shown that such fracture also occurs during non-contact sports such as soccer and skiing and in high-energy trauma such as motor vehicle accidents [48]. The most commonly utilized classification system is the modified Meyers and McKeever system based on fragment displacement [47, 49].

24.4.2 Classification, Associated Injuries and Workup 24.4.2.1 Classification The classification system of tibial spine fractures was first described by Meyers and McKeever [50] which is based on the degree of displacement of the tibial spine fragment. It continues to be widely used to classify fractures and guide treatment (Figure). • Type I: minimal displacement of the fragment from the rest of the proximal tibial epiphysis • Type II: displacement of the anterior third to half of the avulsed fragment, which is lifted upwards but remains hinged on its posterior border in contact with the proximal tibial epiphysis • Type III: complete separation of the avulsed fragment from the proximal tibial epiphysis, with upward displacement and rotation

24  Juvenile Fractures Around the Knee

a

257

b

c

Rockwood and Green in Fractures in Children [6]

However, this classification was limited by its ability to differentiate between type II and III fractures, particularly in describing comminuted fractures of the medial and lateral plateau. Subsequently,

the classification was modified by Zaricznyj [51] to include comminuted avulsion type IV fractures and further subdivide type III fractures into “not rotated” and “rotated” (Figure) [51].

H. Alhamzah et al.

258 Type I

Type IIIA

Type II

Type IIIB

Type IV

Modified Meyers and McKeever classification according to Zaricznyj [51]

24.4.2.2 Associated Injuries The tibial spine, also known as the tibial intercondylar eminence, is the elevated region between the articular portions of the medial and lateral tibial plateaus. The ACL attaches between the lateral aspect of the medial tibial spine and the tibial eminence, 10–14 mm behind the anterior border of the tibia. Both mid-substance ACL tears and tibial spine fractures may occur in skeletally immature patients, but the intercondylar eminence is more prone to failure than the ligamentous structures that attach to it due to the relatively weak, incompletely ossified tibial epiphysis [13]. Secondary injuries in paediatric tibial spine fractures are common, but generally less severe. When they do occur, most are secondary ligamentous injuries around the knee and meniscal injury. A prospective multicentre review study (n  =  54

subjects) identified an incidence of 37% at arthroscopy for meniscal injuries in patients undergoing surgical treatment for tibial eminence fractures. The lateral meniscus was involved in 18/20 patients (90% of all meniscus injuries) and the medial meniscus in 2/20 patients (10% of all meniscus injuries) [52]. The most common tear pattern was a longitudinal tear of the posterior horn of the lateral meniscus (30% of all meniscus injuries), which is an expected finding given that these tears are from a non-contact pivoting mechanism such that occurs in skeletally mature patients. Another study also reviewed retrospectively tibia spine fractures and associated cruciate and collateral ligament injuries. Although clinically 23 patients (51%) had a positive anterior drawer test, none had a positive pivot shift test [53]. This laxity has been attributed to interstitial tearing of the anterior cruciate ligament that

24  Juvenile Fractures Around the Knee

occurs before the fragment is avulsed. Despite the clinical laxity, no patient in this study complained of any subjective feeling of knee instability. No patients were identified to suffer from collateral ligament injury. Collateral ligament injury is extremely rare, and only case reports have been reported [54]. Thus, obtaining magnetic resonance imaging to further characterize meniscal and/or collateral injuries in tibial eminence fracture may be beneficial, especially if one is considering non-operative management, and therefore associated injuries would not be found at surgery. Historically, the most common situation where a child suffers a tibial spine fracture has been a fall from a bicycle. However, with increased participation in youth sports at earlier ages and at higher competitive levels, tibial spine fractures resulting from sporting activities are being seen with increased frequency. The most common biomechanical scenario leading to tibial spine fracture is forced valgus and external rotation of the tibia, although tibial spine avulsion fractures can also occur from hyperflexion, hyperextension or tibial internal rotation. As with ACL injury, tibial spine fractures in sports may result from both contact and non-contact injuries [6], and for the latter the associated meniscal injuries parallel that seen in the skeletally mature.

24.4.2.3 Signs and Symptoms Patients typically present with a painful, swollen knee after an acute traumatic event. They are usually unable to bear weight on their affected extremity. On physical examination, there is often a large hemarthrosis because of the intra-­ articular fracture and limited motion due to pain, swelling and occasionally mechanical impingement of the fragment in the intercondylar notch. Sagittal plane laxity is often present, but the contralateral knee should be assessed for physiologic laxity. Gentle stress testing should be performed to detect any tear of the medial collateral ligament (MCL) or lateral collateral ligament (LCL) or physeal fracture of the distal femur or proximal tibia. Patients with late malunion of a displaced tibial spine fracture may lack full extension because of a mechanical bony block and/or have increased knee laxity, with a positive

259

Lachman and pivot shift examination [6]. As noted by Little et  al., patients with tibial spine fractures present with a primary complaint of knee pain with motion, large immediate knee effusion and a knee that is held in the flexed position with limited range of motion secondary to pain and muscle spasm. Extension can be blocked by the fragment as well. It is difficult to assess knee stability because of pain-mediated muscular spasm and guarding, but an anterior drawer test or Lachman’s exam may be positive [13].

24.4.2.4 Imaging Radiographs  Anteroposterior and lateral radiographs will demonstrate a tibial spine fracture, with the degree of displacement best evaluated on the lateral view. Radiographs often underestimate the size of the avulsed fragment, which is largely cartilaginous. When routine radiographs show only small flecks of bone in the intercondylar notch, MRI may be useful to further assess the injury [12]. CT scan  May be used for pre-operative planning and to better quantify the amount of displacement of the fragment [13]. MRI  Unlike CT scan, it does not involve radiation. It is also useful in evaluating concomitant meniscal and collateral ligament injuries given their high incidence of association with tibial spine fractures [13].

24.4.3 Treatment Principles of treatment are to achieve anatomic reduction of the fracture and preserve knee motion and stability [55]. Non-displaced type I and reducible type II fractures may be treated non-operatively [56, 57]. Closed reduction manoeuvre involves hyperextension of the knee with or without hemarthrosis aspiration. The knee is then immobilized in extension for 3–4  weeks [13, 56]. Cylindrical casts and conventional knee immobilizers have both been used with success [49]. Close follow­up is required to monitor for any loss of fracture

260

reduction. CT may be used to confirm reduction if plain radiograph is not clear [49, 56]. An entrapped meniscus or inter-meniscal ligament can be a barrier to reduction [58, 59]. Any displaced type II, III and IV fractures require operative management via arthroscopy or open arthrotomy [49]. Although there is limited literature comparing the two approaches, arthroscopic approach is more commonly utilized compared to open arthrotomy [49, 55, 57]. It may lead to a reduced likelihood of extension loss, but definitive evidence is lacking. The arthroscopic technique begins with debridement of hematoma and surrounding soft tissues to facilitate anatomic reduction of the fragment and allow bony contact to promote healing. Either a screw or suture fixation (and in some cases combined fixation) is then utilized for fracture fixation [57]. Current literature does not support one method over the other [57]. However, one must carefully decide on the fixation method based on fracture type, skeletal maturity and surgeon’s comfort level with the method [49]. One of the proposed benefits of suture fixation is greater biomechanical strength under cyclical loading compared to screw fixation [60]. Other comparative studies have also found less re-­ operation rates using suture fixation [61]. Suture fixation also allows for suturing the anterior cruciate ligament directly, which may help stabilize it from stretch injury. This modification is often only needed in older, teenaged patients. Screw fixation, in comparison, is a well-­ documented method utilized over many years and may offer earlier mobilization and weight-­ bearing during rehabilitation which is key to prevent loss of full extension and stiffness [62]. In patients with open physes, it is recommended to consider intra-operative fluoroscopy to confirm all-epiphyseal placement of the screw or bony tunnels for suture repair.

24.4.4 Effect on Growth Although avoiding damage to growth plates is a main concern in ORIF of paediatric eminence

H. Alhamzah et al.

fractures, there were no reports of growth arrest in the current review reported [63]. There were two reported cases in one study with documented growth arrest and angular deformity; but both were secondary to growth disturbance from a distal femur physeal fracture that occurred with manual manipulation to treat arthrofibrosis following a tibia spine fracture [64]. Good outcomes are expected for fractures of the tibial spine, at least in the short term. Nonunion of properly treated fractures is rare. Several authors have documented both anterior cruciate laxity and loss of full knee extension despite healing of the fracture in an anatomic position. This laxity has been attributed to interstitial tearing of the anterior cruciate ligament that presumably occurs before the fragment is avulsed. Late laxity varies according to the severity of the initial injury and the extent of damage to the ligament itself. Compared with type I injuries, greater laxity has been noted after type II and III fractures. Despite the laxity, few patients appear to complain of pain or instability. Few long-term studies of this injury have been published. After an average of 16 years, Janarv et  al. [65] followed 61 children with anterior tibial spine fractures and found that most patients had a good clinical result at long-term follow-up. They found no evidence to suggest that the anterior knee laxity resulting from the injury diminished over time. Because of the persistent laxity of the anterior cruciate ligament, which has been documented in several studies, the long-term prognosis for this injury remains unclear, and parents of children with this injury should be appropriately counselled [12]. However, despite the clinical laxity, no patient in that study mentioned above complained of any subjective feeling of knee instability [54]. Whether some residual laxity in the ACL leaves the patient at risk for complete rupture, much like partial ACL tears, is unclear but worth consideration. Given the high success rate of ACL injury prevention programmes, we recommend high-risk children (engaged in cutting/pivoting sports) with residual laxity undergo injury prevention rehabilitation.

24  Juvenile Fractures Around the Knee

24.5 P  atellar and Patellar Sleeve Fractures 24.5.1 Epidemiology It is an uncommon fracture in paediatric population, with an estimate of less than 1% of all paediatric fractures [66]. It most commonly affects adolescent boys, with peak incidence at the age 12–13 [66]. It is characterized by separation of the cartilage “sleeve” from the ossifying patella. The likelihood of adolescents’ susceptibility is probably related to the high competitiveness nature of sporting activity and rapid growth. In addition, osteochondral transformation at the periphery of the patella and the direct attachment of the patellar and quadriceps tendons to that vulnerable histological location (unlike in adults where the tendon attachment is to bone through Sharpey’s fibres)  likely  contribute  to the increased risk in the adolescents [67]. The common mechanism of injury is a rapid explosive contraction of the quadriceps on a flexed knee. It usually occurs during acceleration activities, i.e. jumping or aggressive landing (e.g. skateboarding) [68].

261

In a retrospective study of 47 skeletally immature patients, he described avulsions of the superior, inferior, medial (which often accompanies an acute lateral dislocation of the patella) and lateral patella (which they attributed to chronic stress from repetitive pull from the vastus lateralis muscle) and transverse and stellate fractures [69].

Articular cartilage

24.5.2 Classification, Associated Injuries and Workup 24.5.2.1 Classification Fractures of the patella are generally classified according to the location, pattern and degree of displacement [12]. Houghton and Ackroyd described the so-called sleeve fracture that occurs through the cartilage on the inferior pole of the patella [68]. In children, approximately half of patella fractures are “sleeve fractures” [67]. A large sleeve of cartilage is pulled off the main body of the patella along with a small piece of bone from the distal pole. This is produced by a rapid contraction of the quadriceps on a flexed knee. The diagnosis of this injury may be missed because the distal bony fragment is not readily discernible on radiographs. However, other features such as patella alta (compared to the contralateral knee) should be considered. Grogan et  al. [69] also previously described patella fractures based on the location of injury.

24.5.2.2 Associated Injuries There are few reported associated injuries with a patella/sleeve fracture. However, some secondary conditions may be present at the time of injury and are thought to pre-dispose. These include repetitive stress conditions such as Osgood-­ Schlatter’s disease, Sinding-Larsen-Johansson disease or avulsed fragments seen in children with fixed flexion deformities from neuromuscular conditions such as cerebral palsy or arthrogryposis [70]. 24.5.2.3 Signs and Symptoms Patients with fracture of the patella present with local tenderness, soft tissue swelling and a hemarthrosis of the knee joint. Active extension of the knee is difficult, especially against resistance. A palpable gap at the lower end of the patella suggests the presence of a sleeve fracture. A high-­

H. Alhamzah et al.

262

riding patella implies that the extensor mechanism has been disrupted. With marginal fractures, local tenderness and swelling are present over the medial or lateral margin of the patella, and straight leg raising may still be possible. The presence of an avulsion fracture of the medial margin suggests an acute patellar dislocation that may have reduced spontaneously. When an acute patellar dislocation is suspected, other findings, such as tenderness over the medial retinaculum and a positive apprehension sign, might also be noted on physical examination [12].

67–69, 73]. Early fixation is crucial to prevent complications. Several case series and authors’ techniques are described in the literature, including trans-osseous sutures, modified tension band wiring, intra-osseous suture anchors and interfragmentary screws [67, 73, 74]. There is no established gold standard technique. Care to properly restore the cartilage surface is important.

24.5.2.4 Imaging Radiographs  Are necessary to evaluate fractures of the main body of the patella. Transverse fractures are best seen on the lateral view. A lateral radiograph taken with the knee in 30° of flexion may better ascertain the soft tissue stability and true extent of displacement. Small flecks of bone adjacent to the inferior pole in a patient who has sustained an acute injury may indicate that a sleeve fracture is present. Marginal fractures that are oriented longitudinally may be best seen on a skyline-view radiograph [12].

Ossification of this patella bone begins at age 3–5 years old. There are multiple small ossification centres in the middle of the patella, and ossification progresses peripheral and leaving a rim of soft osseochondrous transformation around the patella. Disruption of the periosteum occurs over the body of the patella and takes osseo-­ potent transformation zone cells from the osseo-­ chondral zone of the patella with it [67]. This means at the lower pole of the patella avulsion, there is a collection of potent bone-forming tissue that can go on to form bone resulting in enlargement or even duplication of the patella in missed or neglected cases with significant initial displacement [72]. Other complications for delayed management of patella sleeve fractures include permanent disability with patella alta and subsequent instability, extensor lag, quadriceps wasting and weakness and patella pain associated with osteochondral damage [75]. Prompt diagnosis and straightforward treatment can be expected to produce an excellent result with full return to all activities, no extensor lag and full flexion.

MRI  May be useful for diagnosing a sleeve fracture when the diagnosis is not clear from the clinical and plain radiographic findings [12].

24.5.3 Treatment Principles of treatment are to achieve anatomic reduction and restore the extensor mechanism [27, 71]. Non-operative management with cast immobilization in extended position is reserved for non-displaced or minimally displaced (