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Table of contents :
Foreword
Preface
Acknowledgments
Contents
About the Authors
1: Vertebroplasty and Kyphoplasty: An Overview
1.1 Introduction
1.2 VP vs. BKP: Literature Review
1.3 Guidelines for Percutaneous Vertebroplasty and Kyphoplasty
1.4 New Materials and Further Evolution of Augmentation Techniques
References
2: Surgical and Radiological Anatomy of the ThoracoLumbar Spine for Vertebroplasty and Kyphoplasty
2.1 Introduction
2.2 Vertebral Body Architecture
2.3 Vascular Anatomy
2.4 Vertebral Strengths
2.5 Vertebral Body Shape
2.5.1 Cervical
2.5.2 Dorsal
2.5.3 Lumbar
2.6 Radiological Anatomy
2.6.1 The Pedicle View
2.6.2 Surgical Landmarks
References
3: Biomechanics of the Spine and Materials Employed in Vertebroplasty, Kyphoplasty, and Augmentation Techniques
3.1 Biomechanics of Spine
3.2 Bone Properties
3.3 Spine Properties
3.4 Neurophysiologic Properties
3.5 Filler Materials
3.5.1 Polymethylmethacrylate
3.5.2 Calcium Phosphate
3.5.3 VK100®
3.5.4 Cortoss®
References
4: Indications and Contraindication of Vertebroplasty and Kyphoplasty
4.1 Introduction
4.2 Patient Selection
4.3 Neuroradiology
4.4 Indication to Percutaneous VP/BKP
4.4.1 Painful Osteoporotic VCF Refractory of Analgesic Therapy
4.4.2 Painful Fractures in Patients Affected by Osteonecrosis (Kümmell Disease)
4.4.3 Painful Vertebrae Due to Benign Bone Tumors
4.4.4 Painful Vertebrae Affected by Osteolytic Metastatic Spinal Disease (MSD) or Pathologic Fractures
4.4.5 Acute Stable A1 and A3 Traumatic Fracture (Magerl’s Classification)
4.4.6 Augmentation Techniques Combined with Posterior Fixation
4.5 Absolute Contraindications
4.6 Relative Contraindications
4.7 The Economic Burden of VP and BKP
4.8 Conclusions
References
5: Technique of Vertebroplasty
5.1 Operating Room Set Up and Patient Positioning
5.2 Surgical Landmarks
5.3 Jamshidi Needle Introduction
5.3.1 Starting Point
5.3.2 Advance of the Needle
5.3.3 Histologic Biopsy Sample
5.4 Filling Material Preparation
5.5 Cement Injection
5.6 Postoperative Care
References
6: Technique of Kyphoplasty
6.1 Introduction
6.2 Operative Management
6.2.1 Malpositioning of the Working Cannula
6.2.2 Biopsy and Balloons Introduction
6.2.3 Cement Introduction
6.2.4 Balloon Positioning
6.2.5 Completion of the Procedure
References
7: Alternative Techniques: Elastoplasty, Vesselplasty, The Kiva System, Spine Jack, Lordoplasty, and Discoplasty
7.1 Elastoplasty
7.2 Vesselplasty
7.3 The Kiva® System
7.4 Spine Jack®
7.5 Lordoplasty
7.6 Discoplasty
References
8: Complication Avoidance and Management
8.1 Introduction
8.2 Postoperative Pain
8.3 Cement Leakage
8.4 Fractures of Ribs, Posterior Elements or Pedicle
8.5 Infections
8.6 Segmental Artery Injury
8.7 Systemic Complications and Allergic Reaction
8.8 Adjacent Vertebral Body Fractures
8.9 Vertebral Instability
8.10 Radiation Exposure
8.11 Mortality
References
9: Osteoporotic Vertebral Fractures
9.1 Introduction
9.2 Risk Factors
9.3 Osteoporosis
9.3.1 Classification
9.3.2 Clinical Features
9.4 Management
9.4.1 Selective Estrogen Receptor Modulators
9.4.2 Bisphosphonates
9.4.3 Peptides of the Parathyroid Hormone Family
9.4.4 Denosumab
9.4.5 Romosozumab
References
10: Traumatic Vertebral Fractures
10.1 Epidemiology
10.2 Patient Evaluation
10.3 Classification
10.3.1 Historical Review
10.3.2 Thoracolumbar Injury Classification and Severity Score
10.3.3 AO Spine Thoracolumbar System
10.4 Surgical Management
References
11: Pathologic Vertebral Fractures
11.1 Introduction
11.2 Therapeutic Option for Metastatic Spine Disease
11.3 Vertebroplasty and Kyphoplasty
11.4 Multiple Myeloma
11.5 Vertebral Hemangioma
11.6 Complications
11.7 Controversial Issues
11.8 VP/BKP and Radiosurgery
11.9 Complications After Spine Stereotactic Radiosurgery
References
12: Open Kyphoplasty and its Role in “Separation Surgery”
12.1 Introduction
12.2 Surgical Technique
12.3 Literature Review
12.4 Discussion
12.5 OKP and Separation Surgery
12.6 The Role of Prognostic Scales in MSD
References
13: Innovative Brachytherapy Techniques and Radiofrequency Ablation
13.1 Brachytherapy
13.1.1 Targeting and Planning
13.1.2 Implantation
13.1.3 Post-Planning
13.2 Radiofrequency Ablation
13.2.1 Indications and Contraindications
13.2.2 Surgical Technique
13.2.3 Literature Review
13.2.4 Complications
13.2.5 Postoperative Evaluation
13.3 Cryoablation
13.4 Microwave Ablation
13.5 Conclusions
References
14: Future Developments of Vertebroplasty and Kyphoplasty Techniques
References
Correction to: Pathologic Vertebral Fractures
Correction to: Chapter 11 in: S. Telera et al., Vertebral Body Augmentation, Vertebroplasty and Kyphoplasty in Spine Surgery, https://doi.org/10.1007/978-3-030-76555-2_11
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Vertebral Body Augmentation, Vertebroplasty and Kyphoplasty in Spine Surgery Stefano Telera Laura Raus Valerio Pipola Federico De Iure Alessandro Gasbarrini

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Vertebral Body Augmentation, Vertebroplasty and Kyphoplasty in Spine Surgery

Stefano Telera • Laura Raus Valerio Pipola • Federico De Iure Alessandro Gasbarrini

Vertebral Body Augmentation, Vertebroplasty and Kyphoplasty in Spine Surgery

Stefano Telera Department of Neurosurgery IRCCS National Cancer Institute “Regina Elena” Roma Italy

Laura Raus Department of Neurosurgery IRCCS National Cancer Institute “Regina Elena” Roma Italy

Valerio Pipola Department of Oncologic and Degenerative Spine Surgery IRCCS Istituto Ortopedico Rizzoli Bologna Italy

Federico De Iure Spine Surgery Department “Maggiore” Hospital AUSL Bologna Bologna Italy

Alessandro Gasbarrini Department of Oncologic and Degenerative Spine Surgery IRCCS Istituto Ortopedico Rizzoli Bologna Italy

ISBN 978-3-030-76554-5    ISBN 978-3-030-76555-2 (eBook) https://doi.org/10.1007/978-3-030-76555-2 © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2021, corrected publication 2022 This work is subject to copyright. All rights are solely and exclusively licensed 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

Foreword

The spine or more appropriately the spinal column is the main supporting structure of the human body. The column is not composed of a single piece but as in Greek Archaic Doric temples, it is made of several pieces that are placed one over the other. The vertebral bodies are similar, but are mobile and articulated. Nevertheless, if the column collapses it needs an external or internal reparation to lift up it again, a process called “Anastylosis”. A collapsed or a partially broken doric column may be repaired and sustained with a circumferential metallic cage as well as the spinal column. A doric column may also be repaired with injections, through the spaces between the rings or inside the stone, of consolidating composite materials, respecting its beautiful profile. A similar approach can be pursued for the spinal column: either stabilization of the vertebrae with external cages and screws or, when indicated and technically feasible, with internal injection of stabilizing materials: acrylic cement or others substances, through mini-invasive procedures called Vertebroplasty and Balloon Kyphoplasty. This book is aimed to thoroughly describe the augmentation techniques that can be applied in daily practice, dealing with traumatic, degenerative, or neoplastic pathologies of the spine, to improve its function and to restore its wonderful shape.

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Foreword

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Greek Doric Temples at “Parco Archeologico di Selinunte,” Trapani, Italy

Alfredo Pompili Department of Neurosurgery IRCCS National Cancer Institute, “Regina Elena” Rome, Italy

Preface

The role of spinal surgeons and interventional radiologists for the treatment of vertebral compression fractures has progressively increased in the last decades thank to the significant developments in minimally invasive surgical procedures. The number of patients who can take advantage from these techniques, which are usually associated with a rapid reduction of pain, a decreased perioperative morbidity, and an improved early mobilization, has also significantly expanded. The purpose of this book is to provide an updated and comprehensive overview of vertebral augmentation techniques such as vertebroplasty and balloon kyphoplasty, with their recent developments and evolutions in terms of surgical techniques, innovative instrumentations, filling materials, and other combination therapeutic strategies. Each of the 14 chapters covers a specific topic with a description of the indications, contraindications, benefits, limitations, and complications of the different procedures, based on the review of the evidence reported in literature and on authors’ experience. The text is integrated with drawings and pictures to convey, as much as possible, the tricks and mastery relative to the various described approaches and devices. The book is aimed at both young spine surgeons and interventional radiologists, who firstly approach such minimally invasive techniques, but also to more skilled surgeons and other busy practitioners or clinicians, who desire to concisely update their knowledge in this evolving field. Rome, Italy Rome, Italy  Bologna, Italy  Bologna, Italy  Bologna, Italy 

Stefano Telera Laura Raus Valerio Pipola Federico De Iure Alessandro Gasbarrini

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Acknowledgments

The authors would like to thank: Mrs. Maria di Santo Mrs. Federica Falcioni Mr. Carlo Piovani for the drawings in the chapters. Mrs. Marzia Piccoli for Editorial Assistance. Mrs. Isabella Sperduti for Statistical Analysis. This book is dedicated to the loving memory of Fabrizio Caroli, MD (1954–2017), our dear friend and colleague, who introduced augmentation techniques at IRCCS National Cancer Institute “Regina Elena.”

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Contents

1 Vertebroplasty and Kyphoplasty: An Overview����������������������������   1 2 Surgical and Radiological Anatomy of the ThoracoLumbar Spine for Vertebroplasty and Kyphoplasty������������������������������������  19 3 Biomechanics of the Spine and Materials Employed in Vertebroplasty, Kyphoplasty, and Augmentation Techniques����������������������������������������������������������������������������������������  39 4 Indications and Contraindication of Vertebroplasty and Kyphoplasty������������������������������������������������������������������������������  47 5 Technique of Vertebroplasty ����������������������������������������������������������  69 6 Technique of Kyphoplasty ��������������������������������������������������������������  85 7 Alternative Techniques: Elastoplasty, Vesselplasty, The Kiva System, Spine Jack, Lordoplasty, and Discoplasty��������������������������������������������������������������������������������  97 8 Complication Avoidance and Management ���������������������������������� 109 9 Osteoporotic Vertebral Fractures �������������������������������������������������� 133 10 Traumatic Vertebral Fractures ������������������������������������������������������ 149 11 Pathologic Vertebral Fractures������������������������������������������������������ 159 12 Open Kyphoplasty and its Role in “Separation Surgery”������������ 189 13 Innovative Brachytherapy Techniques and Radiofrequency Ablation �������������������������������������������������������� 211 14 Future Developments of Vertebroplasty and Kyphoplasty Techniques���������������������������������������������������������� 231 Correction to: Pathologic Vertebral Fractures�������������������������������������  C1

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About the Authors

Stefano  Telera  has been a Consultant Neurosurgeon at “Santa Corona” Hospital in Pietra Ligure (SV) since 2001 and at the IRCCS National Cancer Institute “Regina Elena” in Rome since 2002. His main field of practice and research is cerebral and spine neuro-oncology with 40 articles published in peer-reviewed international journals. He is currently the Director of the Neurosurgical Department of “Regina Elena.” Laura Raus  has been jointly responsible for various research programs on neuro-oncology promoted by the Italian National Research Board (CNR), Ministry of Health, and Italian League Against Cancer (AIRC). A Consultant Neurosurgeon at the IRCCS National Cancer Institute “Regina Elena” in Rome, Italy, since 1992, with a particular interest in spinal oncological surgery, she holds one international patent and has published 30 articles in peerreviewed international journals. Valerio  Pipola  specialized in Orthopedics and Traumatology at the University of Bologna. He spent most of the residency program dedicating himself to the study and treatment of spinal pathologies, focusing in particular on primary and metastatic spine tumors and publishing about 20 articles on the topic in international journals. Since March 2021, he is Consultant Surgeon at the Department of Oncologic and Degenerative Spine Surgery of Istituto Ortopedico Rizzoli. Federico  De Iure  specialized in Orthopedics and Traumatology at the University of Bologna. A Consultant Orthopedics Surgeon at “Maggiore” Hospital in Bologna, Italy, since 1996, he has also been Head of the Spine Surgery Unit at the “Maggiore” Hospital in Bologna since 2009. A member of the North America Spine Society (NASS), Italian Society of Vertebral Surgery, AO Spine, and Italian Society of Orthopedics and Traumatology (SIOT), he is Principal Investigator for the European Study on Vertebral Trauma (SCI-POEM). He has published over 120 articles in Italian and international journals. Alessandro Gasbarrini  specialized in Orthopedics and Traumatology at the University of Bologna. From 1998 to 2009, he worked as Consultant Surgeon at “Maggiore” Hospital in Bologna, distinguishing himself in the management

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of musculoskeletal oncology, in particular of spine. From 2009 to 2017 he was responsible for the treatment of metastatic tumor of the spine at the Department of Oncologic and Degenerative Spine Surgery of Istituto Ortopedico Rizzoli, becoming Director of the same unit since January 2018. He published more than 275 articles in national and international journals.

About the Authors

1

Vertebroplasty and Kyphoplasty: An Overview

1.1

Introduction

A vertebral compression fracture (VCF) can be defined as a reduction of the vertebral body height by 20% related to different etiologies as osteoporosis, hemangioma, solid and hematologic neoplastic disease (myeloma, lymphoma, metastasis), osteonecrosis, and trauma (Fig. 1.1). This pathologic condition may cause a debilitating back pain with severe consequences on quality of life, neurologic and physical function,

a

psychosocial performance, mental health and overall survival. In industrialized countries, 5.2  million nontraumatic fractures are expected to take place every year, of which 2.8  million involving the hip or the spine (Tsoumakidou et al. 2017). In a population-based study performed in Rochester, Minnesota between 1985 and 1989 the authors observed an incidence rate of 117 cases per 100,000 person-years (95%CI:105–130) with an etiology related in 14% of  the cases to severe

b

Fig. 1.1 (a) Biconcave osteoporotic fracture of L4, (b) Metastatic fracture of D6 secondary to lung cancer © The Author(s), under exclusive license to Springer Nature Switzerland AG 2021 S. Telera et al., Vertebral Body Augmentation, Vertebroplasty and Kyphoplasty in Spine Surgery, https://doi.org/10.1007/978-3-030-76555-2_1

1

2

1  Vertebroplasty and Kyphoplasty: An Overview

Fig. 1.2 Operative setting to perform an augmentation technique (vertebroplasty or kyphoplasty), with two easily oriented C-arm fluoroscopy systems

trauma, in 83% to moderate or no trauma and in 3% to cancer disease (Cooper et al. 1992). In the past three decades, vertebroplasty (VP) and balloon kyphoplasty (BKP) have emerged as minimal invasive surgical options that play a central role for the treatment of VCFs (Fig. 1.2). VP is a therapeutic procedure which involves the percutaneous injection of a filling material, such as bone cement polymethylmethacrylate (PMMA), calcium phosphate, hydroxyapatite, or silicone into an injured vertebral body, via a needle placed through a transpedicular or extra-­pedicular approach. The goals are to stabilize the VCF, to prevent further vertebral compression and to relieve the associated pain. The injection of the filling material has to be forced to reach a pressure that surpasses the local trabecular bone pressure of the fractured vertebra (Figs. 1.3 and 1.4). BKP is a technical modification of VP in which a small balloon is percutaneously introduced and inflated in the broken vertebra, with the aim to create a cavity inside its body and compacting the cancellous bone around it. Following the deflation and removal of the balloon, the cavity is filled by injection of the cement. Although BKP is more expensive than VP, advocated advantages include the possibility (1) to correct to some degree, kyphosis with eleva-

tion of the vertebral body plates; (2) to decrease the rate of cement leakages through a lower pressure delivery of more viscous filling materials, in a preformed cavity; and (3) to reduce the incidence of subsequent adjacent fractures (Xing et al. 2013; Ruiz Santiago et al. 2014; Lee et al. 2009; Hulme et al. 2006; Garfin et al. 2001a, b; Taylor et al. 2007) (Figs. 1.5 and 1.6). Before the introduction of the so-called Augmentation Techniques such as VPs and BKPs, the only surgical option for treatment of VCFs was an open decompression and fusion. However, surgical fixation frequently fails in elderly or osteoporotic patients because of osteopenia and this is not always a feasible procedure for fragile patients, such as the oncological ones. A new plastic material composed by polymers of methyl methacrylate, with novel structural properties and a good biocompatibility, called polymethylmethacrylate (PMMA), was developed by chemist Otto Röhm in the early twentieth century. In 1958, Sir John Charnley began using self-­ curing PMMA as a bone cement in orthopedic surgery, to fix the femur and acetabulum for total hip replacement. PMMA acted as a filler, fitting itself in the voids between the metal prosthesis and the bone. Since then, acrylic cements have been used in different orthopedic applications,

1.1 Introduction

a

3

b

c

Fig. 1.3  Vertebroplasty: (a) the working cannulas are inserted in the vertebral body through a percutaneous approach; (b) the cement is introduced overcoming the local trabecular bone pressure of the fractured vertebra;

a

(c) intraoperative fluoroscopic images of cannulas insertion and cement intrasomatic injection. (drawing by Federica Falcioni)

c

b

Fig. 1.4 (a) Cervical vertebroplasty through an anterior approach; (b) vertebroplasty of D11. Progressive cement filling of the D11 dorsal vertebra through a percutaneous

access of the cannula; (c) L3 lumbar vertebroplasty at the end of the procedure

1  Vertebroplasty and Kyphoplasty: An Overview

4

a

b

c

Fig. 1.5  Kyphoplasty: (a) the balloon is percutaneously introduced and inflated in the fractured vertebra, with the aim to create a cavity inside its body. Following the removal of the balloon, the cavity is filled by the cement; (b) operative setting showing the balloons inserted in the

a

d

vertebral body and slowly inflated with radio-opaque contrast medium by means of an inflation syringe under strict fluoroscopic guidance and pressure control; (c) the appearance of a deflated and (d) inflated balloon. (drawing by Federica Falcioni)

b

Fig. 1.6 (a) Intraoperative lateral and (b) anteroposterior radioscopic view of a lumbar kyphoplasty with the balloon inflated in the vertebral body

1.1 Introduction

for the augmentation of weakened or partially destroyed bones. In vertebral column, PMMA was employed as a means to strengthen the purchase of pedicle screws in spinal instrumentation procedures, or as a vertebral body substitute after a total or partial somatectomy, for neoplastic diseases. In 1981, Harrington described the open surgical treatment and the strengthening of the vertebral body with cement, in 14 patients affected by spinal metastases (Harrington 1981). Advantages such as biocompatibility, ease of handling, considerable mechanical strength, and cost-effectiveness made PMMA an ideal choice as bone cement (Lavelle et  al. 2007; He et  al. 2015). The VP procedure was first performed in 1984 by Galimbert and Deramont in the Department of Radiology of the University Hospital of Amiens, France. The patient was a 54-year-old female affected by a large vertebral angioma which completely involved the C2 vertebra, with epidural extension. She underwent a cervical laminectomy, removal of the epidural component of the angioma and a percutaneous injection of 3  mL of PMMA, through an anterolateral approach. The results in term of pain remission were so impressive that the procedure was further employed in other 6 patients and the experience of VPs were first reported by Galimbert et al. in 1987 (Galibert et  al. 1987; Mathis et  al. 2001; Deramond et al. 1998). The technique was subsequently refined (1) adding a contrast medium to the PMMA, to show the distribution of the cement during injection, and (2) selecting the transpedicular approach as the most suitable one, to reduce the risk of cement leakage and possible compression of the neural structures. Due to the brilliant results in terms of pain control and strengthening of the vertebral body, with such very limited surgical approach, VP procedures progressively gained a large popularity both in Europe and in the USA. Indications in 1990s had already included malignant and benign tumor lesions, angiomas, traumatic and osteoporotic VCFs. In 1989, Kaemmerlen et al. used this technique for the treatment of patients with vertebral body metastases, while the encouraging

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analgesic effects prompted the use of augmentation techniques also in osteoporotic VCFs as reported by Gangi et  al. in 1994 (Kaemmerlen et  al. 1989; Gangi et  al. 1994; Armsen and Boszczyk 2005; Lieberman et al. 2001). VP was introduced in the USA in 1993, with the first U.S. case series reported in 1997 by the interventional neuroradiologist team at the University of Virginia and in 2004, the Food and Drug Administration (FDA) formally approved bone cement for VCFs related to osteoporosis and tumors (Jensen et al. 1997; He et al. 2015). Severe pain associated with VCF, is a very common medical problem, affecting between 700,000 and one million patients every year in the US alone and the demographics are similar in Europe. Most of these fractures are the result of bone mineral loss due to primary osteoporosis occurring progressively with age. However, an increasing number of fractures also result from secondary osteoporosis caused by therapeutics drugs and catabolic steroids, anticonvulsants, cancer, chemotherapy and heparin (Burton et al. 2011; Eichholz et al. 2006). Until the introduction of VP, treatment options for osteoporotic VCFs consisted of bed rest, spinal orthosis and pain management therapy. The immediate and lasting pain relief attained with VP have progressively changed the standard medical care of treatment of such patients and the procedure has been diffusely employed worldwide. VP was reported to reduce pain within 48 to 72 h, in 90% to 95% of patients with osteoporotic VCFs. Significant improvements in mobility and decreased use of pain medications were also noted. Due to its low surgical morbidity, VP has also been increasingly chosen as palliative treatment for patients with pathologic VCFs to relieve pain, to structurally augment vertebral bodies compromised by osteolytic lesions and to maintain to some extent, mobility and weight-bearing activities of daily living. The success rate was slightly less prominent in patients with metastatic disease compared to patients with osteoporosis, with approximately 65% to 80% of them reporting notable improvement in pain scores (Eichholz et al. 2006). Nevertheless, these results appeared

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particularly significant in patients with advanced metastatic spine disease (MSD) in which there is an increased demand of palliative treatments, to improve or maintain quality of life during the remaining course of their disease. VP and BKP procedures for patients with traumatic VCFs remain less extensively studied, due to the frequent complexity of these injuries and the heterogeneous affected population. More than half of such patients are younger than 60 years and the primary concerns in these subjects are to control their pain, to strengthen their spine and to let them to return to daily activities as soon as possible with long-lasting results (Knavel et al. 2009). The precise mechanism of the analgesic effect of VP is not completely understood. The polymerization reaction of PMMA cement is exothermic, with temperatures that can reach up to 122 °C. In the past, the reduction of pain has been attributed to the toxic and/or thermal effect of PMMA, assuming that the pain originates from intra-osseous nerve endings. However, a cadaveric study on osteoporotic vertebrae, found that temperatures generated during VP, may not be sufficient to result in widespread thermal necrosis of osteoblasts or nerve endings. It is more likely that the filling materials act as means of internal fixation, through interdigitation with bone and immobilization of the trabecular micro-­ fractures, after solidification. Mechanical stability may prevent inflammation of the periosteum and bone marrow. Whatever the involved mechanisms, injection of bone cement into painful VCFs, turned out to be a successful technique, with well-published clinical effective results (Lavelle et al. 2007; Denaro et al. 2009). With time, some drawbacks of VP were also perceived, as the high pressures required to introduce viscous cement inside the trabecular bone of the fractured vertebrae, which potentially could lead to cement extravasation, severe neurologic consequences or embolization from the vertebral venous channels, to the lungs. Additionally, VP was also felt to be inadequate to restore vertebral height. To solve these issues in the early 1990s, the orthopedic surgeon Mark Reiley developed the

1  Vertebroplasty and Kyphoplasty: An Overview

idea to treat a VCF more completely, with the intrasomatic insertion of an inflatable balloon tamp that should precede the cement injection, with the aim to restore the vertebral body height and minimize kyphotic deformity. The initial biomechanical investigations of the KyphX® inflatable balloon tamp (Kyphon Corporation, Sunnyvale, CA) were performed as combined efforts by the same Reiley and the interventional neuroradiologist JM Mathis and in 1998, the device received the FDA approval as a “bone tamp.” The first report on the BKP procedure in osteoporotic fractures was published by Garfin et al. in 2001. This group also performed a descriptive literature review and found that 95% of patients treated with BKP or VP showed a significant improvement in pain. BKP also improved height of the fractured vertebra and kyphosis by 50%, if performed within 3 months from the onset of the fracture or the pain (Garfin et al. 2001a, Garfin et al. 2001b). Lieberman et al. in 2001 published the results of a phase I study of the inflatable bone tamp used in BKP. Seventy BKP were studied in 30 patients. Pain scores improved significantly as a result of the procedure from 11.6 to 58.7 (p  =  0.0001). Physical function scores also demonstrated significant improvement as SF 36 score changed from 11.7 to 47.4, (p = 0.002). Cement leakage was observed in 8.6% of the cases but without major complications (Lieberman et al. 2001). In 2003, Ledlie and Renfro followed 133 kyphoplasty patients for 1 year. In this series, a significant reduction in visual analog pain scores from an average of 8.6/10 pre-procedure to 1.6/10 post-procedure was observed. Thirty-five percent of the patients reported unassisted pre-procedure ambulation, whereas 90% reported unassisted post-procedure ambulation. In a separate multicenter study, 90% of patients treated by BKP were able to return to their baseline activities and 90% were also able to wean off narcotic medications (Lavelle et  al. 2007; Ledlie and Renfro 2003). Since then, a vast body of literature has been generated attempting to evaluate and compare the two procedures. Indeed, VP and BKP are similar but not the same techniques with some distinct differences, including cost and complication rates. The real hurdles are to properly assess

1.2  VP vs. BKP: Literature Review

and develop the appropriate indications, advantages and shortcomings of each procedure and to tailor the right technique to the need of the single patient (Lavelle et al. 2007). Recent systematic reviews help to clarify the differences between the two procedures in terms of efficacy, complications rates and selective indications. The main controversies between VP and BKP concern the clinical relevance of height restoration afforded by the latter technique. BKP is approximately 5–10 times more expensive than a VP performed in a patient with conscious sedation on a day-surgery basis. Additional costs of a BKP include the device itself, the cost of the anesthesia, duration of the procedure, and patient’s hospitalization.

1.2

VP vs. BKP: Literature Review

Taylor et al. in 2007 published a comparative systematic review of VP and BKP in cases of VCFs due to osteoporosis or neoplasm, which included one prospective study comparing VP to medical care, one prospective and two retrospective studies comparing BKP to medical care, one prospective study comparing the two procedures, and 70 case series. In the pooled case series data comprising 4861 fractures treated by VP and 1070 fractures treated by BKP, a similar significant reduction of pain was achieved for VP, with up to 5  years of follow-up, and for BKP, with up to 2 years of follow-up. BKP significantly improved functional capacity measured by the Oswestry Disability Score and Index of Back Function; reported outcomes with a validated instrument of patient function were lacking for VP. Furthermore, BKP improved quality of life in six of eight Short-Form 36 domains reported by patients. VP also improved quality of life in three of four studies, but results could not be pooled because different outcome measures were used. When compared with medical therapy, BKP was superior for improving both pain and patient function, whereas VP improved patient function but not pain. In the only study that directly compared VP with BKP, the authors found a similar level of pain relief between the two procedures as mea-

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sured by a Visual Analog Scale (VAS), but there was a significant selection bias in application of the procedures, with more severe compression fractures receiving BKP.  In comparative studies and case series, BKP resulted in significant improvement of vertebral body height and kyphotic deformity. However, data from analyzed case series, also demonstrated a certain degree of improved vertebral height and kyphotic angle with VP (Taylor et al. 2007). A second systematic review encompassing 69 clinical studies was performed by Hulme et al. in 2006 and included 4456 VP and 1624 BKP procedures. For a study to be included in the analysis, at least 80% of the treated vertebral compression fractures had to be related to osteoporosis. A comparable percentage of patients noted at least “some pain relief” with VP (87%) and BKP (92%). Follow-up observation was short (