The Hip Joint [2 ed.] 9814877514, 9789814877510

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The Hip Joint

Second Edition

edited by

K. Mohan Iyer

Published by Jenny Stanford Publishing Pte. Ltd. Level 34, Centennial Tower 3 Temasek Avenue Singapore 039190 Email: [email protected] Web: www.jennystanford.com

British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library.

The Hip Joint Copyright © 2022 by Jenny Stanford Publishing Pte. Ltd. All rights reserved. This book, or parts thereof, may not be reproduced in any form or by any means, electronic or mechanical, including photocopying, recording or any information storage and retrieval system now known or to be invented, without written permission from the publisher.

For photocopying of material in this volume, please pay a copying fee through the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, USA. In this case permission to photocopy is not required from the publisher.

ISBNԘ978-981-4877-51-0 (Hardcover) ISBNԘ978-1-003-16546-0 (eBook) DOI: 10.1201/9781003165460

I have written this dedication with a very heavy mind, full of fond memories for my respected teacher, late Mr. Geoffrey V. Osborne, without whose constant encouragement and freedom I could not have written this book. Such teachers are extremely rare to spot these days where the turmoil of daily life overtakes one’s ambitions, duties, and career aspirations. I have a remarkable store of personal and academic memories of him, with whom I spent four long years at the University of Liverpool, UK, during which I rarely looked upon him as my teacher as he was more of a close friend and father to me. I also dedicate this book, with loving thanks, to

My wife, Mrs. Nalini K. Mohan

My daughter, Deepa Iyer, MBBS, MRCP (UK), FAFRM (RACP) [Honorary adjunct assistant professor, Bond University, Queensland, and senior lecturer, rifϔith University and University of Queensland, AustraliaȐ My son-in-law, Kanishka B.

My son, Rohit Iyer, BE (IT)

My daughter-in-law, Deepti B.U.

My grandsons, Vihaan and Kiaan

My grandchild, Nisha Iyer

Contents

Foreword Preface 1. Applied Anatomy of the Hip Joint K. Mohan Iyer 1.1 The Hip Joint 1.2 Ligaments of the Hip Joint 1.3 Movements of the Hip Joint 1.4 Bursae around the Hip Joint 1.4.1 Iliopsoas Bursa 1.4.2 Trochanteric Bursa 1.4.3 Ischiogluteal Bursa 1.5 Vascular Supply 1.6 Nerve Supply 1.7 Stability of the Hip Joint 1.8 X-Rays of the Pelvis 1.8.1 Hip X-Ray Anatomy 1.9 Hip Ultrasound 1.10 Commonly Seen Sports Injuries of the Hip Joint 1.10.1 Avulsion Injuries of the Hip 1.10.2 Snapping Hip Syndrome 1.10.3 Adductor Muscle Strain 1.10.4 Iliopsoas Strain 1.10.5 Trochanteric Bursitis 2. Biomechanics of the Hip Joint K. Mohan Iyer 2.1 Introduction 2.2 Biomechanics of the Hip Joint 2.2.1 First-Order Lever 2.2.2 Joint Reaction Force 2.2.3 Forces Acting across the Hip Joint

in a Two-Leg Stance 2.2.4 Use of Assistive Devices

xxxiii xxxv 1

1 3 5 6 6 6 7 7 7 8 8 9 9 11 11 11 11 11 12 13

13 18 18 19 22 23

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Contents

2.3 2.4 2.5 2.6

2.2.4.1 Canes 2.2.4.2 Walkers 2.2.4.3 Crutches Biomechanics of Trendelenberg’s Gait Biomechanics of Neck Deformities Biomechanics of Weight Gain Biomechancis of Total Hip Replacement

3. Septic Arthritis of the Hip in Children K. Vinodh 3.1 Introduction 3.2 Epidemiology 3.3 Anatomical Considerations and Aetiopathology 3.4 Pathogens 3.5 Clinical Features 3.6 Diagnostic Evaluation 3.6.1 Laboratory Investigations 3.6.2 Imaging Studies 3.7 Diagnostic Aspiration 3.8 Differential Diagnosis 3.9 Management 3.9.1 Choice of Antibiotics 3.9.2 Predictors of Poor Prognosis 3.10 Sequelae of Septic Arthritis of the Hip in

Children 3.10.1 Chondrolysis 3.10.2 Dislocation with the Capital Femoral

Epiphysis Intact 3.10.3 Sequelae Related to AVN of the CFE

and Growth Plate Damage 3.10.3.1 Treatment options for

Hunka type I 3.10.3.2 Treatment options for

Hunka type II 3.10.3.3 Treatment options for

Hunka type III 3.10.3.4 Treatment options for

Hunka types IV and V 3.10.3.5 Ilizarov’s reconstruction 3.10.4 Role of Arthroscopy

23 23 24 24 25 25 26 29

29 30 30 32 33 34 34 35 38 39 40 41 43 43 44 45 46 47 48 48 50 52 53

Contents

4. Developmental Dysplasia of the Hip Munis Ashraf and Senthilnathan Sambandam 4.1 Graf Classification of DDH Using

Ultrasonography 4.1.1 Reliability 4.2 Radiographic Classification of DDH 4.2.1 Tönnis and IHDI Classifications 4.2.1.1 Tönnis classification of DDH 4.2.1.2 IHDI classification of DDH 4.2.2 Reliability 4.3 MRI Classification of DDH 4.3.1 Kashiwagi Classification for

Prediction of Reduction 4.3.2 Clinical Application 5. Bearing Materials in Total Joint Arthroplasty Hemant Kumar Singh, Arya Mishra,

Sharad Goyal and Conal Quah

5.1 Introduction 5.2 Tribology 5.2.1 Material Strength: Stress versus

Strain Curve 5.3 Biomaterials 5.3.1 Polymers 5.3.1.1 Disadvantages of

cross-linking 5.3.2 Metals 5.3.2.1 Strengthening mechanisms 5.3.2.2 Orthopaedic implant alloys 5.3.2.3 Postproduction

strengthening mechanisms 5.3.3 Ceramics 5.3.3.1 Manufacture of ceramic biomaterials 5.4 Bearing Surface Couplings and Their Clinical

Performance 5.4.1 Ceramic-on-Ceramic 5.4.1.1 Early setbacks and the current situation

63

63 65 65 65 65 66 68 68 68 68 71

71 72 73 76 77 78 79 81 82 83 85 86 92 95 95

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Contents

5.4.1.2 5.4.1.3 5.4.1.4

5.5

5.6 5.7

Tribological characteristics

and wear mechanisms Stripe wear Systemic effects of wear

particles Advantages Disadvantages

97 97

98 5.4.1.5 98 5.4.1.6 98 Polyethylene Liners 100 5.5.1 Clinical Performance of Polyethylene

Liners 100 5.5.2 Second-Generation HXLPE 101 5.5.3 Metal-on-Polyethylene 102 5.5.3.1 Advantages 103 5.5.3.2 Disadvantages 103 5.5.4 Ceramic-on-Polyethylene 103 5.5.4.1 Advantages 103 5.5.4.2 Disadvantages 104 5.5.5 Oxinium-on-Polyethylene 104 5.5.5.1 Advantages 105 5.5.5.2 Disadvantages 105 5.5.6 Metal-on-Metal 106 5.5.6.1 Tribological characteristics

and wear mechanisms 106 5.5.6.2 Advantages 107 5.5.6.3 Disadvantages 107 Discussion 109 Summary 109

6. 3D Printing: Clinical Applications in Orthopaedics

and Traumatology Mohit Kumar Patralekh and Hitesh Lal 6.1 Introduction 6.2 Methods 6.3 Basic Technique of 3D Printing 6.4 Applications in Orthopaedic Traumatology:

Examples from Management of

Pelvi-Acetabular Trauma and Proximal

Femoral Fractures 6.4.1 Acetabular Fractures

121

121 123 125

127 127

Contents

6.4.2

6.5

6.6

6.7

6.8

6.9

6.10

6.11 6.12 6.13

Hip Dislocation with Acetabular

Fracture 6.4.3 Pelvic Trauma 6.4.4 Sacral Fractures 6.4.5 Proximal Femur Recent Advances and Techniques on the

Horizon in 3D Printing Applications in

Hip Trauma 6.5.1 Atypical Femoral Fracture with

Bowed Femur Appropriate Nail

Decided Using 3D Printing Applications in Hip Preservation Surgery

and Arthroscopy 6.6.1 Periacetabular Osteotomies 6.6.2 Osteonecrosis of the Femoral Head 6.6.3 Femoro-Acetabular Impingement 6.6.4 Hip Arthroscopy, FAI and 3D Printing Applications in Hip Arthroplasty 6.7.1 Revision Hip Arthroplasty 6.7.2 Custom Prosthesis 6.7.3 Patient-Specific Instrumentation Applications in Orthopaedic Oncology 6.8.1 Tumour 6.8.2 Shepherd’s Crook Deformity Applications in Paediatric Orthopaedics 6.9.1 Slipped Capital Femoral Epiphysis 6.9.2 Paediatric Hip Fractures 6.9.3 Development Dysplasia of the Hip Applications in Plastic Surgery Related to

Limbs 6.10.1 Illustrative Case 6.10.2 Evolving Areas in 3D Bioprinting Applications in Rehabilitation: Patient-

Specific Orthoses and Prostheses Reliability of 3D-Printed Models Conclusion

7. Stem Cell Therapy in Orthopaedics Ben Davies and Wasim Khan 7.1 Introduction

130 130 131 132

132

133 133 133 134 136 136 137 139 139 140 141 141 142 143 143 143 143 144 144 145 146 147 147 157 158

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Contents

7.2 7.3 7.4 7.5 7.6 7.7

Limitations of Conventional Alignment Jigs Types of Computer Navigation Systems Computer Navigation in Total Hip

Arthroplasty Computer Navigation in Total Hip

Resurfacing Limitations of Computer Navigation Systems Conclusion

8. Principles of Anterior Approach for Total Hip

Arthroplasty Alessandro Geraci, Paolo Segnana and

Alberto Ricciardi

8.1 Introduction 8.2 Surgical Technique 8.2.1 Choice of Patients 8.2.2 Patient Positioning 8.2.3 Skin Incision 8.2.4 Superficial Dissection: The

Intramuscular Approach 8.2.5 Deep Dissection: The Intramuscular

Approach 8.2.6 Femoral Preparation: The Use of the

Traction Table 8.2.7 Femoral Preparation: The Use of the

Traditional Table 8.2.8 Dedicated Surgical Instruments 8.3 Intra-operative Digital Imaging 8.4 Advantages of Anterior Hip Replacement 8.5 Disadvantages of Anterior Hip Replacement 8.6 Conclusions 9. Periprosthetic Fractures of the Hip Joint Shibu Krishnan, Gurdeep S. Biring and Arvind Vijapur 9.1 Introduction 9.2 Epidemiology 9.2.1 Risk factors 9.3 Classification of Periprosthetic Fractures 9.3.1 The Vancouver Classification System 9.3.2 The Unified Classification System

159 160 160 163 164 165

171

171 172 172 173 174 176 176 179 180 182 183 184 185 185 189

189 190 191 191 192 196

Contents

9.4 9.5

9.6

9.7

Clinical Diagnosis of Periprosthetic Fractures 9.4.1 Investigations Treatment 9.5.1 Surgical Approach 9.5.1.1 Pre-operative workup

and planning 9.5.2 Non-operative Treatment Surgical Management of Periprosthetic

Acetabular Fractures 9.6.1 Surgical Considerations in the

Management of Periprosthetic

Femoral Fractures 9.6.1.1 Treatment of intra-

operative femur fractures 9.6.1.2 Treatment of post-

operative femur fractures 9.6.2 Post-operative Management 9.6.3 Complications 9.6.4 Prevention Current Controversies and Future

Considerations

10. Periprosthetic Osteolysis after Total Hip Replacement Pranab Sinha and Shalin Shaunak 10.1 Introduction 10.2 Periprosthetic Osteolysis: Current Concepts 10.2.1 Initiation of Osteolysis 10.2.2 Processes Involved in Osteolysis 10.2.3 Cell Types Involved 10.2.4 Alternate Pathways 10.3 Investigation and Monitoring 10.4 Nonsurgical Treatment of Periprosthetic

Osteolysis 10.5 Surgical Treatment of Periprosthetic Osteolysis 11. Surgical Approaches to the Hip Joint Zachary Post and Courtney Bell 11.1 Introduction 11.2 The Posterior Approach 11.3 The Direct Lateral Approach

198 198 199 199 199 200 200

204 204 205 213 213 213 214 219

219 220 220 221 221 223 224 224 225 229 229 230 237

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Contents

11.4 The Direct Anterior Approach 11.5 Conclusion 12. Classifications Used in Total Hip Arthroplasty Munis Ashraf and Senthilnathan Sambandam 12.1 Paprosky Classification of Acetabular

Deficiencies for Revision Hip Arthroplasty 12.1.1 Introduction 12.1.2 Classification 12.1.3 Clinical Applications 12.1.4 Reliability 12.2 Saleh Classification of Acetabular Deficiencies

for Revision Hip Arthroplasty 12.2.1 Introduction 12.2.2 Classification 12.2.3 Reliability 12.3 Hodgkinson Classification of Radiographic

Demarcation of the Socket, Following Total

Hip Arthroplasty 12.3.1 Introduction 12.3.2 Classification 12.3.3 Clinical Significance 12.4 Paprosky Classification of Femoral Bone

Deficiencies 12.4.1 Introduction 12.4.2 Classification 12.4.3 Clinical Applications 12.5 AAOS Classification of Femoral Bone

Deficiencies for Revision Hip Arthroplasty 12.5.1 Introduction 12.5.2 Classification 12.5.3 Clinical Applications 12.5.4 Reliability 12.6 Saleh Classification of Femoral Bone

Deficiencies 12.7 Dossick and Dorr Classification of Proximal

Femoral Geometry 12.7.1 Introduction 12.7.2 Classification

243 251 253

253 253 254 255 255 255 255 255 256

257 257 257 257 257 257 258 258 259 259 259 260 260 260 261 261 261

Contents

12.7.3 Clinical Significance 12.8 Vancouver Classification of Intra-operative

Periprosthetic Femur Fractures around

Total Hip Arthroplasty 12.8.1 Classification 12.8.2 Clinical Applications 12.9 Vancouver Classification of Post-operative

Periprosthetic Femur Fractures around

Total Hip Arthroplasty 12.9.1 Classification 12.9.2 Clinical Applications 12.9.3 Reliability 12.10 Tsukayama Classification of Infected Hip

Joint Prostheses 12.10.1 Introduction 12.10.2 Classification 12.10.3 Clinical Applications 12.11 Brooker’s Classification of Heterotopic

Ossification 12.11.1 Introduction 12.11.2 Classification 12.11.3 Clinical Applications 12.11.4 Reliability 12.12 Barrack Grading of Cementing 12.12.1 Introduction 12.12.2 Classification 12.12.3 Clinical Applications 12.13 Crowe Classification of Proximal Migration

of the Femoral Head in DDH 12.13.1 Introduction 12.13.2 Classification 12.13.3 Clinical Applications 12.13.4 Reliability 12.14 Hartofilakidis Classification of Hip

Dysplasia 12.14.1 Introduction 12.14.2 Classification 12.14.3 Clinical Applications 12.14.4 Reliability

262

262 262 264

264 264 265 265 265 265 265 266 266 266 267 268 268 268 268 268 268 268 268 269 269 270 270 270 270 271 271

xv

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Contents

13. Total Hip Arhroplasty Sharad Goyal, Chris Booth, Sarah Sexton

and Madhu Rao

13.1 Introduction 13.2 Primary Total Hip Arthroplasty 13.2.1 History 13.2.1.1 Chronology 13.2.2 Indications 13.2.3 Symptoms of Hip Pathology 13.2.4 Signs of Hip Pathology 13.2.5 Radiographic Features of

Degenerative Hip Joint Disease 13.2.6 Investigations 13.2.7 Treatment 13.2.7.1 Initial management 13.2.7.2 Medical management 13.2.7.3 Surgical management 13.2.8 Components of Hip Replacement 13.2.9 Types of Hip Replacements 13.2.9.1 Cemented joint replacement 13.2.9.2 Uncemented joint

replacement 13.2.9.3 Hybrid replacement 13.2.10 Types of Materials Used in Joint

Replacement Surgery 13.2.11 Surgical Approaches 13.2.11.1 Direct lateral transgluteal

(Hardinge) approach 13.2.11.2 Posterior approach 13.2.11.3 The Charnley approach 13.2.11.4 Minimally invasive surgery 13.2.11.5 Direct anterior approach 13.2.12 Complications 14. Hip Resurfacing Gareth Chan, Sharad Goyal and Michael Moss 14.1 Introduction 14.2 Rationale 14.3 Patient Selection 14.4 Complications

275

275 276 276 277 279 281 281 282 282 282 283 283 283 284 284 284 285 286 287 290 290 290 291 291 291 293

297

297 298 299 300

Contents

14.5 14.6

Long-Term Prognosis Future Developments

15. Proximal Femoral Replacement Vineet Kurisunkal and Michael C. Parry 15.1 Introduction 15.2 History of Proximal Femur Replacements 15.3 Indications 15.4 Contraindications 15.5 Pre-operative Planning 15.5.1 Primary Bone Tumours 15.5.2 Metastatic Bone Tumours 15.5.3 Miscellaneous Conditions 15.6 Surgical Approach 15.6.1 Position 15.6.2 Landmarks and Incision 15.6.2.1 Superficial dissection 15.6.2.2 Deep surgical dissection 15.7 Post-operative Rehabilitation 15.8 Advantages and Disadvantages 15.9 Current Evidence on Proximal Femur

Replacements 15.10 Conclusion 16. Pelvic and Acetabular Reconstruction Following

Oncological Resection Jonathan Stevenson and Scott Evans 16.1 Introduction 16.2 Allografts and APC 16.3 Autografts 16.4 The Harrington Procedure 16.5 Pedestal Cups 16.6 Saddle Prosthesis 16.7 Salvage 16.8 Conclusion 17. Complications of Hip Arthroscopy Stephanie Kokkineli, Christopher J. Feroussis

and Nikolaos V. Bardakos

17.1 Introduction

301 304 307 307 308 309 309 309 309 310 311 311 311 312 312 312 320 321 321 323

327

327 330 330 331 332 334 335 335 339

339

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Contents

17.2 17.3

17.4

17.5

17.6

17.7 17.8

17.9

17.10

17.11

17.12

17.13

Traction and Perineal Post–Related

Complications Portal-Related Neurovascular Complications Iatrogenic Labral and Chondral Injury Fluid Extravasation Iatrogenic Hip Instability Complications of the Femoral Head and Neck:

Osteonecrosis, Chondrolysis and Fracture Deep Venous Thrombosis Infection Heterotopic Ossification Re-admission Other Complications Closing Remarks and Future Directions

18. Femoral Neck-Lengthening Osteotomies around

the Hip Joint Gaurav Garg 18.1 Introduction 18.2 Evaluation of Femoral Deformities 18.3 Indication for Surgery 18.4 Mechanical Effects of Proximal Femoral

Osteotomy 18.5 Types of Proximal Femoral Deformities 18.6 Classification of Proximal Femoral

Osteotomies 18.7 Relative Femoral Neck-Lengthening and

Greater Trochanter Distalisation Osteotomies 18.7.1 Wagner Osteotomy 18.7.2 Morscher Osteotomy 18.7.3 Ganz Relative Neck-Lengthening

Osteotomy 18.8 Contractures around the Hip 18.9 Conclusion 19. Hip-Preserving Surgery Hiran Amarasekera 19.1 Introduction 19.2 Anatomical Considerations and Surgical

Approaches in Hip Preservation Surgery

341 344 345 348 350 351 353 354 354 356 356 359

369

369 370 371 372 374 375 376 378 380 385 388 389

393

393 396

Contents

19.3

19.4

19.5 19.6 19.7

The Scope of Hip Preservation Surgery 19.3.1 Hip Arthroscopy and Arthroscopic Procedures 19.3.1.1 Arthroscopic FAI management and arthroscopic osteochondroplasty 19.3.1.2 Arthroscopic cartilage implantation and microfracture for cartilage growth stimulation Open Hip Preservation Procedures 19.4.1 Osteotomies to Manage Hip Acetabular Alignment and Cup Head Inclinations 19.4.1.1 Femoral osteotomies 19.4.1.2 Peri-acetabular osteotomies and DDH management 19.4.2 Preservation Surgery to Manage and Prevent Osteoarthritis Rehabilitation Following Hip Preservation Surgery Complications and Managing Complications of Hip Preservation Surgery Concluding Notes

20. Extracorporeal Shockwave Treatment of the Hip Kandiah Raveendran 20.1 History 20.2 Physics of Shockwaves 20.3 Mechanism of Action 20.3.1 Shockwave Treatment for Tendinopathy 20.3.2 Shockwave Treatment for Bone Healing 20.4 Clinical Indications 20.5 Greater Trochanteric Pain Syndrome 20.5.1 Introduction 20.5.2 Aetiology

398 399

404

405 406

406 406

406 407 407 407 408 413 414 414 417 417 417 418 419 419 420

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Contents

20.6

20.7

20.8 20.9

20.5.3 Differential Diagnosis 20.5.4 Investigation 20.5.5 Treatment 20.5.6 Technique 20.5.7 Results 20.5.8 Conclusion Avascular Bone Necrosis 20.6.1 Introduction 20.6.2 Aetiology 20.6.3 Classification 20.6.4 Differential Diagnosis 20.6.5 Investigations 20.6.6 Treatment 20.6.6.1 Conservative treatment 20.6.6.2 ESWT 20.6.6.3 Surgery 20.6.7 Technique 20.6.8 Results 20.6.9 Conclusion Common Empirically Tested Clinical Uses 20.7.1 Tendon Pathologies 20.7.1.1 Adductor insertional

tendinopathy syndrome 20.7.1.2 Hamstring tendinopathy 20.7.2 Bone Pathologies 20.7.2.1 Bone marrow oedema

syndrome Complications Conclusions

21. Sports Medicine of the Hip Joint Ashish Mittal 21.1 Introduction 21.2 Epidemiology 21.3 Functional Anatomy 21.3.1 Morphology 21.3.2 Acetabular Labrum 21.3.3 Ligaments of the Hip 21.3.4 Chondral Surface 21.3.5 Muscle Function

420 421 421 422 422 423 423 423 424 424 425 426 426 426 426 427 427 428 428 428 429 429 429 430 430 430 431 435

435 436 437 437 438 438 439 440

Contents

21.4

21.5

21.6

21.7

21.3.6 Short Hip-Stabilising Muscles 21.3.7 Clinical Biomechanics Clinical Approach 21.4.1 History 21.4.2 Physical Examination 21.4.3 Key Outcome Measures 21.4.4 Investigations Predisposing Factors for Hip Pain 21.5.1 Local Factors 21.5.2 Remote Factors 21.5.3 Proximal Factors 21.5.4 Distal Factors 21.5.5 Systemic Factors Hip Pathologies 21.6.1 Femoro-Acetabular Impingement 21.6.1.1 Types of FAI-cam and

pincer impingement 21.6.1.2 Prevalence of FAI 21.6.1.3 Aetiology 21.6.1.4 Association with pain

and pathology 21.6.2 Osteoarthritis 21.6.3 Acetabular Labral Tears 21.6.3.1 Pathology 21.6.4 Ligamentum Teres Tears 21.6.5 Synovitis 21.6.6 Chondropathy 21.6.7 Hip Instability Treatment 21.7.1 Principles of Rehabilitation of the

Injured Hip 21.7.2 Nine Principles of Rehabilitation

for Hip Pain Patients 21.7.2.1 Restore the hip range

of motion 21.7.2.2 Restore hip muscle strength 21.7.3 Improve Balance and Proprioception 21.7.4 Improve Hip Control in Functional

Task Performance 21.7.5 Improve Trunk Muscle Strength

440 440 441 442 443 444 445 446 447 447 447 449 449 449 449 450 451 451 452 452 454 454 456 456 457 458 459 459 460 460 460 462 462 463

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Contents

21.8

21.9

21.7.6 Optimise Gait Biomechanics 463 21.7.7 Optimise Functional Task

Performance 464 21.7.8 Address Adverse Loading 464 21.7.9 Address Other Remote Factors That

May Be Altering the Function of the

Kinetic Chain 464 21.7.10 Criteria for Returning to Sport as

the Final Stage of Hip Rehabilitation 465 21.7.11 Surgical Management of the Injured

Hip 465 21.7.11.1 Rehabilitation following

hip arthroscopy 466 Some Other Major Pathologies 467 21.8.1 Proximal Hamstring Tendinopathy 467 21.8.1.1 Examination 468 21.8.1.2 Treatment 468 21.8.2 Sacroiliac Joint Dysfunction 469 21.8.2.1 Functional anatomy 469 21.8.2.2 Clinical features 470 21.8.2.3 Treatment 470 21.8.3 Myofascial Pain 471 21.8.3.1 Examination 472 21.8.3.2 Treatment of myofascial

buttock pain 472 21.8.4 Lateral Hip Pain 472 21.8.4.1 Greater trochanteric pain 472 21.8.4.2 Iliac crest pain 474 21.8.4.3 Examination of the patient

with lateral hip pain 475 21.8.4.4 Treatment of the patient

with lateral hip pain 476 21.8.4.5 Managing pain 476 21.8.4.6 Managing load: First-line

treatment 477 Less Common Causes of Hip Region Pain 478 21.9.1 Piriformis Syndrome 478 21.9.2 Ischiofemoral Impingment 479 21.9.2.1 Treatment 479 21.9.3 Proximal Hamstring Tendon Rupture 480

Contents

21.9.3.1 Treatment 21.9.4 Avulsion Fracture of the Ischial

Tuberosity 21.9.5 Stress Fracture of the Sacrum 21.9.5.1 Diagnosis confirmed by

MRI and CT scans 21.10 Groin Pain in Athletes 21.10.1 Terminology 21.10.2 Classification 21.10.3 Clinical Overview 21.10.3.1 Pain pattern 21.10.3.2 Where is the pain located? 21.10.3.3 Assessment of severity 21.10.3.4 Strength 21.10.3.5 Range of motion 21.10.3.6 Patient-reported outcome

measures 21.10.3.7 Imaging 21.10.3.8 Radiography 21.10.3.9 Magnetic resonance

imaging 21.10.3.10 Ultrasonography 21.10.3.11 Computed tomography

scan 21.10.4 Acute Groin Injuries 21.10.4.1 Diagnosis 21.10.5 Long-Standing Groin Pain 21.10.5.1 Adductor-related groin

pain 21.10.5.2 lliopsoas-related groin

pain 21.10.5.3 Inguinal-related groin

pain 21.10.5.4 Pubic-related groin pain 21.11 Less Common Injuries 21.11.1 Complete Adductor Avulsion 21.11.2 Obturator Neuropathy 21.11.3 Other Nerve Entrapments 21.11.4 Stress Fracture of the Neck of

the Femur

480 480 481 481 481 482 482 482 482 483 483 484 484 484 484 484 485 485 485 485 486 487 488 490 491 493 493 493 494 494 495

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Contents

21.11.5 Stress Fracture of the Inferior

Pubic Ramus 21.11.6 Referred Pain to the Groin 21.12 Prevention of Groin Injuries 21.12.1 Possible Prevention Strategies 22. Evaluation of a Painful Total Hip Replacement Lee Hoggett and Ardeshir Y. Bonshahi 22.1 Introduction 22.2 Differential Diagnosis 22.3 Intrinsic Causes 22.3.1 Aseptic Loosening 22.3.2 Infection 22.3.3 Instability 22.3.4 Peri-prosthetic Fractures 22.3.5 Inϐlammatory Conditions 22.3.6 Stem Tip Pain: Thigh Pain 22.3.7 Metal-on-Metal 22.4 Extrinsic Causes 22.5 Initial Assessment 22.5.1 History 22.5.2 Examination 22.6 Investigations 22.6.1 Blood Tests 22.6.2 Plain Radiography 22.6.3 Nuclear Medicine 22.6.4 Hip Aspiration/Anaesthetic

Injection 22.6.5 Computed Tomography 22.6.6 Magnetic Resonance Imaging 22.7 Summary 23. Robotic-Assisted Surgery in Orthopaedics Karthik Karuppaiah and Mathew Gee 23.1 Introduction 23.2 Total Hip Arthroplasty 23.2.1 Types of Robotic Systems 23.2.2 Conventional THA vs. Robotic THA 23.2.3 Surgical Technique: MAKO THR

496 496 497 497 505

505 506 507 507 507 508 509 509 510 511 512 513 513 514 515 515 515 518 520 520 521 522 529

529 530 530 531 532

Contents

23.3 23.4 23.5

23.2.3.1 Pre-operative

requirements 23.2.3.2 Acetabular planning 23.2.3.3 Femoral planning 23.2.3.4 Surgical approach 23.2.3.5 Femoral workϐlow 23.2.3.6 Operating room layout 23.2.3.7 Acetabular reaming 23.2.3.8 Femoral preparation 23.2.4 Implant Positioning and Hip

Biomechanics 23.2.5 Functional and Radiological

Outcomes 23.2.5.1 Earlier studies 23.2.5.2 Recent studies Limitations Hip Arthroscopy Summary

24. Computer Navigation in Hip Arthroplasty Benjamin M. Davies, Sarvpreet Singh and

Wasim Khan

24.1 Introduction 24.2 Limitations of Conventional Alignment Jigs 24.3 Types of Computer Navigation Systems 24.3.1 Computer Navigation in Total Hip

Arthroplasty 24.3.2 Computer Navigation in Total Hip

Resurfacing 24.3.3 Limitations of Computer Navigation

Systems 24.4 Conclusion 25. Surgical Advancements in Hip Arthroscopy and FAI Syndrome: Indications and Technique for Labral Reconstruction of the Hip Michael Scheidt, Michael B. Ellman and

Sanjeev Bhatia

25.1 Introduction 25.2 Anatomical Overview of the Labrum

532 533 534 535 535 535 538 538 539 541 541 542 548 549 550 555

556 557 558 559 561 562 564

569

569 572

xxv

xxvi

25.3 Biomechanical Evidence and Rationale

for Labral Reconstruction 25.4 Indications 25.5 Surgical Technique 25.5.1 Patient Positioning and Anaesthesia 25.5.2 Diagnostic Arthroscopy 25.5.3 Acetabuloplasty 25.5.4 Femoroplasty 25.5.5 Labral Reconstruction 25.5.6 Suture Management 25.5.7 Measurement Technique 25.5.8 Graft Preparation 25.5.9 Graft Insertion 25.6 Outcomes 25.7 Conclusion 26. Fracture Neck of the Femur Abdullah Hanoun, Shwan F. Henari and

Vijay Kumar

26.1 Introduction 26.2 Epidemiology 26.3 Risk Factors for Fragility Fractured Neck

of the Femur 26.3.1 Osteoporosis as a Risk Factor for

Fracture Neck of the Femur 26.3.1.1 Bony trabeculae of

the proximal femur:

The Singh index 26.3.1.2 DEXA scan in diagnosing

osteoporosis 26.4 Mechanism of Injury 26.4.1 Associated Injuries 26.5 Fracture Classification 26.5.1 Intracapsular Fracture Classification 26.5.1.1 Garden’s classification 26.5.1.2 Pauwel’s classification 26.5.2 Extracapsular Fracture Classification 26.5.2.1 Intertrochanteric fractures 26.5.2.2 Evan’s classification 26.5.2.3 Subtrochanteric fractures

573 573 575 575 576 577 577 578 579 579 582 583 586 587 595

595 596 597 598

598 599 600 600 600 601 601 602 603 603 603 604

Contents

26.6 26.7 26.8

26.9 26.10

26.11

26.12

26.5.2.4 All-encompassing

classification: AO classification Clinical Presentation Diagnosis Management of Fracture Neck of Femur 26.8.1 Assessment and Management in

the Emergency Department and

the Orthopaedic Ward 26.8.2 Timing of Surgery 26.8.3 Definitive Management of

Intracapsular NOF in the Elderly 26.8.3.1 Nondisplaced

intracapsular fracture NOF 26.8.4 Definitive Management of Displaced

Intracapsular NOF in the Elderly 26.8.5 Surgical Approaches for NOF

Arthroplasty 26.8.6 Definitive Management of

Intertrochanteric Fracture NOF 26.8.6.1 Extramedullary devices 26.8.6.2 Intramedullary devices 26.8.6.3 Arthroplasty 26.8.6.4 Reverse oblique type of

trochanteric fracture 26.8.7 Definitive Management of

Subtrochanteric Fracture NOF Complications of Femoral Neck Fractures

and Treatment Intracapsular Fractures in Young Adults 26.10.1 Who Are Young Patients? 26.10.2 Timing of Surgery 26.10.3 Role of Capsulotomy 26.10.4 Implant Choice Stress Fractures of the Femoral Neck 26.11.1 Definition, Presentation and Risk

Factors 26.11.2 Diagnosis 26.11.3 Treatment and Prognosis Pathological Fracture NOF

607 608 608 609

609 611 611 611 613 618 618 618 619 620 621 621 622 623 623 624 624 625 625 625 626 626 626

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Contents

26.12.1 Neoplastic Fracture 26.12.2 Atypical Femoral Fracture 26.13 Ipsilateral Fracture of the Femoral Shaft

and Neck 26.13.1 Diagnosis 26.13.2 Complications 26.13.3 Management 27. Conversion of Hip Arthrodesis to Total Hip Arthroplasty Omer Faruk Egerci, Adil Turan, Halis Atil Atilla

and Ozkan Kose

27.1 Introduction 27.2 Indications and Contra-indications 27.3 Pre-operative Assessments and Planning 27.3.1 Physical Examination 27.3.2 Imaging 27.4 Surgical Technique 27.4.1 Surgical Exposure 27.4.2 Acetabular and Femoral Preparation

and Implantation 27.5 Clinical Results 27.5.1 Pain Relief in Adjacent Joints 27.5.2 Functional Recovery and Patient

Satisfaction 27.5.3 Prognosis and Survival of the

Converted Hip 27.6 Complications 27.7 Conclusions 28. The Direct Anterior Approach to the Hip Hiran Amarasekera 28.1 Introduction 28.1.1 Background 28.1.2 History 28.1.3 Resurgence of the Approach 28.1.4 Key Advantages and Disadvantages 28.2 The Approach 28.2.1 Indications and Contra-indications 28.2.2 Anatomy 28.2.3 The Traditional Approach

626 627 629 629 630 630 639

639 641 641 641 642 643 643 645 650 650 651 653 655 657 663

664 664 664 665 665 666 666 666 669

Contents

28.2.3.1 Position 28.2.3.2 Incision 28.2.3.3 Approach 28.2.3.4 The internervous plane 28.2.3.5 Capsule arthrotomy 28.2.3.6 Dislocation 28.2.3.7 Surgical procedures 28.2.3.8 Closure 28.2.4 Modifications, New Instrumentation

and Minimally Access Approach 28.2.4.1 Incision 28.2.4.2 Approach 28.2.4.3 The internervous plane 28.2.4.4 Capsule arthrotomy 28.2.4.5 Closure 28.2.4.6 Rehabilitation protocol 28.3 Complications 28.4 Pearls and Pitfalls 28.5 Conclusions 29. Modified PLOP Osteotomy Approach to the Hip Xiaoxiao Zhou and Yang Yang 29.1 Introduction 29.2 The Posterior Hip Anatomy 29.3 Proximal Femur Anatomy 29.4 Development of the Osteotomy of the

Posterolateral Overhanging Part of Greater

Trochanter 29.5 Modified PLOP Osteotomy Approach

Procedures 29.6 Indications for the Modified PLOP

Osteotomy Approach 30. Single-Incision Piriformis-Sparing Posterior THA Benjamin Quansah and Riaz J. K. Khan 30.1 Introduction 30.2 Surgical Technique 30.3 Supporting Evidence 30.3.1 Efficacy of the Piriformis-Sparing Surgical Approach

669 669 669 670 671 671 671 671 671 671 671 671 672 672 672 672 673 674 677

677 679 682

684 688 690 695 695 696 703 703

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Contents

30.4 30.5

30.3.2 Integrity of SER Repair 30.3.3 The Impact of Preserving the

Piriformis 30.3.4 Relative Benefit Compared to

the Standard Posterior Approach 30.3.5 Long-Term Results Discussion Summary

31. Imaging of the Hip Joint Christine Azzopardi and Rajesh Botchu 31.1 Introduction 31.2 Anatomy of the Pelvis 31.3 MRI Anatomy of the Hip 31.3.1 Muscles and Tendons 31.3.2 The Labrum 32. Neoplastic Conditions around the Hip Christine Azzopardi, Ram Vaidhyanath

and Rajesh Botchu

32.1 Introduction 32.2 Osteogenic Tumours 32.2.1 Bone Islands 32.2.2 Osteoid Osteoma and Osteoblastoma 32.2.3 Conventional Osteosarcoma 32.2.4 Surface Osteosarcoma 32.2.5 Periosteal Osteosarcoma 32.2.6 Telangiectatic Osteosarcoma 32.2.7 Low-Grade Osteosarcoma 32.2.8 Secondary Osteosarcoma 32.2.9 Small-Cell Osteosarcoma 32.3 Ewing’s Sarcoma 32.4 Cartilage Tumours 32.4.1 Osteochondroma 32.4.2 Enchondroma 32.4.3 Chondroblastoma 32.4.4 Chondrosarcoma 32.5 Giant-Cell Tumour 32.6 Fibrogenic and Fibrocystic Tumours 32.6.1 Fibrous Cortical Defect

704 705 708 709 709 711 713

713 714 718 720 725 727

727 728 728 729 731 732 732 733 733 734 734 734 735 735 737 737 738 739 740 740

Contents

32.7 32.8 32.9 32.10 32.11 32.12 32.13 32.14 32.15 32.16 32.17 32.18 Index

32.6.2 Desmoblastic Fibroma/Benign

Fibrohistiocytoma 32.6.3 Malignant Fibrohistiocytoma 32.6.4 Aneurysmal Bone Cyst 32.6.5 Unicameral Bone Cyst 32.6.6 Fibrous Dysplasia 32.6.7 Angiosarcoma 32.6.8 Haemangioma Myeloma Lymphoma Metastasis Brown Tumour Osteomyelitis Fractures Stress Fractures Myositis Ossificans ALVAL Paget’s Disease Soft-Tissue Sarcoma Synovial Chondromatosis

741 741 742 743 743 744 745 745 747 747 748 749 751 751 752 753 753 754 755 763

xxxi

Foreword by

William James Hozack, MD [email protected]

I applaud the hard work of Dr. K. Mohan Iyer and the host of distinguished contributors in this update to his fantastic book The Hip Joint, written in 2016. While much basic knowledge in this area remains unchanged, it is critically important to stay updated in those areas that do change. And many things have changed in the past 5 yearsǨ This edition contains original articles contributed by authors from all around the world, presenting various techniques that have evolved for hip joint surgery till the present day. This book successfully addresses and highlights this new knowledge and information, building upon the solid foundation set by the 1st edition. It is my sincere pleasure to be able to write this foreword to the 2nd edition, which is an admirable body of work in itself. William James Hozack is a Walter Annenberg Professor of joint replacement surgery at Sidney Kimmel Medical School, Thomas Jefferson University, and a joint replacement surgeon at Rothman Orthopedic Institute, Philadelphia, USA. He graduated from the Faculty of Medicine and Health Sciences, McGill University, Montreal, Canada, in 1981. He is a member of the prestigious Hip Society and the Knee Society, USA, and has served as the president of the American Association of Hip and Knee Surgeons. He was the editor-in-chief of Journal of Arthroplasty (Elsevier). He has authored and co-authored the books A Prospective Study in One-Stage Bilateral Total Hip Arthroplasty Compared with Unilateral Total Hip Arthroplasty; Surgical Treatment of Hip Arthritis: Reconstruction, Replacement, and Revision; and

xxxiv

Foreword

Direct Anterior Hip Exposure for Total Hip Arthroplasty. Dr. Hozack is currently focused on rapid recovery programs for total hip and knee replacement.

Preface

Preface

In the recent years, arthroscopic surgery of the hip has evolved into one of the most rapidly expanding ϐields of orthopaedic surgery. It has become a well-established technique in the last decade and an essential part of a surgeon’s armamentarium in the treatment of hip disorders. While working on this 2nd edition of my book, under the prevailing tense circumstances gripping the world, it was really difϐicult for me to decide on Chapter 8, Principles of Anterior Approach for THA, and Chapter 28, Direct Anterior Approach to the Hip Joint, because this surgical approach on the hip joint has evolved worldwide since the ϐirst edition of the book, and it has also been dealt with in Chapters 11, 13, and 26 of this edition. Then I just followed my intuition that these chapters should be written by senior authors who are routinely involved in this type of surgery of the hip joint. I have done only a few cases in hemiarthroplasty (without using a fracture table) in selective patients, which I felt were not sufϐicient to write the chapters. This surgical approach involves a difϐicult learning curve and specialised surgical skills with special instruments, including a special operation table for the surgery. In fact, total hip surgery can be done as a day case, as has been presented by Dr. med. Manfred Krieger and Dr. med. Ilan Elias, Germany, in Chapter 18 of my book Hip Joint in Adults: Advances and Developments. Therefore, I felt that Dr. John O’Donnell, Australia, is the ideal person to write on DAA. During my several interactions with him, he had mentioned that he is extremely comfortable with DAA for hip replacements and cannot imagine himself switching to any other surgical approach. This is when I developed an interest in the DAA. He has also been instrumental in writing a foreword for a small book Pocket Book of Orthopedics (Lambert Academic Publishing, Germany), written by me in 2018. Nevertheless, I would never persuade any colleague orthopaedic surgeon for the approach as it should be their judgement call. I must make it a point to mention that in Chapter 23, author Karthik Karuppaiah, King’s College Hospital, London, has included one of his colleagues Mr. Mathew Gee, who does robotic hip

xxxv

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Preface

replacement, to write the technique in this chapter. I am particularly happy to say that I am extremely thankful to Michele Sparer for kindly giving permission on behalf of Strykar to reproduce pictures from Mako“ regarding planning, etc. The foreword has been given by Dr. William Hozack, an orthopaedic surgery specialist having over 39 years of experience in the ϐield. He has a worldwide reputation for excellence in hip and knee replacement surgery and is board certiϐied in orthopaedic surgery. He educates orthopaedic surgeons from around the world on his techniques. I am extremely grateful to Drs. K. Vinodh, Munis Ashraf, Senthilnathan Sambandam, Hemant Kumar Singh, Arya Mishra, Sharad Goyal, Conal Quah, Mohit Kumar Patralekh, Dr. (Prof.) Hitesh Lal, Benjamin M Davies, Wasim Khan, Alessandro Geraci, Hiran Amarasekera, Shibu Krishnan, Gurdeep S. Biring, Arvind Vijapur, Pranab Sinha, Shalin Shaunak, Zachary Douglas Post, Courtney Danae Bell, Chris Booth, Sarah Sexton, Madhu Rao, Gareth Chan, Michael Moss, Vineet Kurisunkal, Michael C. Parry, Jonathan Stevenson, Scott Evans, Nikolaos Bardakos, Stephanie Kokkineli, Christopher Feroussis, Gaurav Garg, Raveendran S. Kandiah, Ashish Mittal, Lee Hoggett, Ardeshir Y. Bonshahi, Karthik Karuppaiah, Mathew Gee, Sarvpreet Singh, Michael Scheidt B. S., Michael B. Ellman, Sanjeev Bhatia, Abdullah Hanoun, Shwan F. Henari, Vijaya Hosahalli Kempanna, Omer Faruk Egerci, Adil Turan, Halis Atil Atilla, Ozkan Kose, Xiaoxiao Zhou, Yang Yang, Benjamin Quansah, Prof. Riaz J. K. Khan, Christine Azzopardi, Rajesh Botchu, and Ram Vaidhyanath for contributing their valuable and unique chapters to this book. I also thank the team at Jenny Stanford Publishing for their invaluable support in publishing this book. Above all, I highly appreciate the help of my son, Mr. Rohit Iyer, who was blessed with his ϐirst child, Nisha Iyer, amid the preparation and publication of this book. K. Mohan Iyer MBBS, FCPS Orth., D’Orth., MS Orth., Mumbai, India MCh (Orth.), Liverpool, UK Bengaluru, Karnataka, India Summer 2021

Chapter 1

Applied Anatomy of the Hip Joint

K. Mohan Iyer Formerly Locum Consultant Orthopaedic Surgeon, Royal Free Hampstead NHS Trust, Royal Free Hospital, Pond Street, London NW3 2QG, UK [email protected]

1.1 The Hip Joint The hip joint is a ball-and-socket type of a synovial joint where the articular surfaces are formed by the head of the femur, which articulates with the acetabulum of the hip bone. It is the largest joint of the body, having a very high degree of mobility and stability, which makes it unique in every way. The articular surface of the acetabulum is of horseshoe shape formed by the pubis ilium and ischium bones and is deϐicient inferiorly at the acetabular notch. The cavity of the acetabulum is deepened by a ϐibrocartilaginous rim called the acetabular labrum. Its depth starts at the age of 8, and its depth increases by puberty due to the development of 3 secondary centres of ossiϐication. This labrum bridges across the acetabular notch, where it is called the transverse acetabular ligament. The articular surfaces are covered by hyaline cartilage. The acetabulum The Hip Joint Edited by K. Mohan Iyer

Copyright © 2022 Jenny Stanford Publishing Pte. Ltd.

ISBN 978-981-4877-51-0 (Hardcover), 978-1-003-16546-0 (eBook)

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2

Applied Anatomy of the Hip Joint

allows the proximal transmission of weight from the axial skeleton to the lower extremity. The femur is the largest bone in the body and consists of the head, neck and two trochanters, greater and lesser. A cross-sectional view of the normal hip joint is shown in Fig. 1.1 [1].

Figure 1.1 Cross-sectional view of the normal hip joint. Figure reproduced by courtesy of Byrne et al. [1].

It has been observed that labral tears are most likely to occur at the junction of the labrum and articular cartilage; this area has been termed the ‘watershed’ region [2]. The head of the femur is covered with hyaline cartilage except at the fovea capitalis, which serves at the attachment of the ligamentum teres. The femoral neck is externally rotated with respect to the shaft, thus forming the angle of anteversion. In normal adults the neck forms an angle of 135° with the shaft. The normal angle is 120° to 135°. In coxa valga, the angle is >135° while in coxa vara it is 3 years

S. aureus

Flucloxacillin/Vancomycin

Teenagers

S. aureus

Flucloxacillin/Vancomycin

There has been considerable controversy regarding the duration of antibiotics. Recently there has been a trend towards shorter duration of antibiotics [4, 5, 72]. Intravenous antibiotics should be given for the ϐirst 3–4 days and changed over to oral antibiotics once there is improvement in the clinical picture and a drop in CRP levels. About 2–3 weeks of antibiotics appear to be sufϐicient in most uncomplicated cases, as long as the CRP normalises and the patient’s clinical picture improves, irrespective of the organism and age of the patient. The dose of oral antibiotics is much higher than in less serious infections. Serum bacteriocidal activity of 1:8 is needed for an effective outcome. Longer duration of antibiotics may be necessary in delayed presentations and in patients having associated osteomyelitis. If the anticipated improvement in the

Sequelae of Septic Arthritis of the Hip in Children

clinical picture is not seen, or there is persistently high CRP, reexploration and joint irrigation may have to be considered and associated osteomyelitis, if present, needs to be decompressed. MRI scan at this stage is an effective tool to assess the problem. Harel et al. did a randomised controlled trial in 49 children with and without the addition of dexamethasone and found that the addition of steroids leads to lower fever, fewer local inϐlammatory signs, fewer elevated acute-phase proteins and less intravenous treatment [73]. In selected cases perhaps, there is a role for steroids, especially in those with septicaemia. All patients with septic arthritis of the hip need a prolonged period of follow-up to detect any late sequelae.

3.9.2 Predictors of Poor Prognosis The mortality rate has come down considerably to less than 1% compared to 60% in the pre-antibiotic era. However, the complication rate can be as high as 40%.The single-most important factor associated with poor prognosis is a delay in starting treatment beyond 4–5 days [74]. In one study, there was an 81.8% unsatisfactory result when there was a delay in starting treatment beyond 5 days [75]. Other risk factors for poor prognosis are prematurity, children who are less than 6 months of age and those with associated osteomyelitis.

3.10 Sequelae of Septic Arthritis of the Hip in Children Septic arthritis of the hip in children is an orthopaedic emergency. Though the systemic complications and mortality rate have considerably decreased in the post-antibiotic era, delay in diagnosis and treatment will lead to catastrophic complications which can cripple the child for life. The single-most important factor which can cause complications and poor eventual outcome is a delay in starting treatment [74–76]. In one study there was only 38.7% complete resolution when there was a delay in presentation [77]. Neonatal age and the type of organism, like MRSA, are also factors predisposing

43

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Septic Arthritis of the Hip in Children

to complications [76]. The complications can be varied and include chondrolysis, dislocation, osteonecrosis of the capital femoral epiphysis (CFE), early fusion of the triradiate cartilage, acetabular dysplasia, incomplete or complete damage of the proximal femoral physis with valgus or varus deformity or increased anteversion or retroversion, trochanteric overgrowth, ϐibrous ankylosis, shortening of the limb, pseudarthrosis of the femoral neck and complete destruction of the femoral head and neck. The problems can be so varied that no cookbook type of guidelines can be given. The treatment has to be individualised, and the best-available option has to be offered to the patient. Several procedures have been described to treat these complications, but very few have given consistently reliable long-term results.

3.10.1

Chondrolysis

Chondrolysis takes place due to the action of proteolytic enzymes released from the chondrocytes, synovial cells, polymorphs and bacteria. Streptococcal and staphylococcal infections produce severe chondrolysis compared to septic arthritis due to other organisms [78]. This will lead to pain, progressive decrease in the range of motion and ϐibrous ankylosis. The actual incidence of chondrolysis is not clear; in one study on a review of 227 hips, it was reported as 2.2% [79]. In the early post-operative period, walking children should be kept non-weight-bearing, and range-of-movement exercises should be advised. Persisting pain and a decrease in the range of movements should warn us about the possibility of chondrolysis. Serial radiographs will show a gradual reduction in joint space. If the symptoms don’t improve with physiotherapy, traction and analgesics, arthrodiastasis using an articulated distractor can be tried. The distraction should be maintained for a minimum period of 3–4 months to see any regeneration of articular cartilage (Fig. 3.7). In established cases with pain and gross restriction of the range of motion, the options are arthrodesis and arthroplasty at a later stage. Arthrodesis is not an acceptable option for most patients at present.

Sequelae of Septic Arthritis of the Hip in Children

(A)

(B)

(C)

(D)

Figure 3.7 (A) A 13-year-old boy presented with septic arthritis of the right hip about 10 days after the onset of symptoms. (B) 3 months’ postdrainage radiograph showing severe chondrolysis. (C) Undergoing distraction. (D) 1-year follow-up radiograph showing good regeneration of the articular cartilage.

3.10.2 Dislocation with the Capital Femoral Epiphysis Intact If the patient presents within 3–4 days with acute septic arthritis of the hip, immobilisation of the hip is not necessary following arthrotomy and drainage. However, if the child is brought late or if there is any suspicion of hip subluxation or dislocation, a hip spica cast should be applied. The spica should be changed every 6 weeks till the hip is clinically and radiologically stable. In infants the capital epiphysis may not be ossiϐied, in which case the status of the head should be assessed by ultrasonography, MRI or arthrogram. All efforts should be made to reduce the hip and maintain it in the acetabulum. If closed reduction is unsuccessful, open reduction should be performed. The acetabulum should be cleared of all the soft tissues and the head reduced. Additional procedures, as

45

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Septic Arthritis of the Hip in Children

necessary, will have to be carried out. These procedures include adductor and psoas tenotomy, femoral shortening, varus osteotomy, shelf and Chiari osteotomy for dysplastic acetabulum. Johari et al. reviewed a group of patients who had dislocated hips with an intact CFE and noted the following factors associated with poor outcomes: hip stiffness, AVN of the CFE, premature fusion of the triradiate cartilage and cartilage thinning on MRI on pre-operative assessment and femoral head ϐlattening and coxa magna, cartilage thinning, marked ϐibrosis and adhesions on intra-operative ϐindings [80].

3.10.3 Sequelae Related to AVN of the CFE and Growth Plate Damage Septic arthritis can result in a variety of anatomical abnormalities due to damage to the CFE and physis. To systematically describe these deformities and plan on treatment, Hunka described (Fig. 3.8) a classiϐication system [81]: ∑ Type I: Absent or minimal femoral head changes ∑ Type II: o II A: Deformity of the femoral head, with an intact growth plate o II B: Deformity of the femoral head, with premature fusion of the growth plate

Figure 3.8 Hunka’s classification.

Sequelae of Septic Arthritis of the Hip in Children

∑ Type III: Pseudarthrosis of the femoral neck ∑ Type IV: o IV A: Complete destruction of the proximal femoral epiphysis, with a stable neck segment o IV B: Complete destruction of the proximal femoral epiphysis, with a small unstable neck segment ∑ Type V: Complete destruction of the head and neck to the intertrochanteric line, with dislocation of the hip Choi described a classiϐication system after analysing a large series of cases and proposed possible treatment options for each type [82]. He classiϐied hips into four groups and each group into two subgroups: ∑ Type I: No residual deformity (I A) or mild coxa magna (I B) ∑ Type II: Coxa breva with a deformed head (II A) or progressive coxa vara or coxa valga due to asymmetrical premature physeal closure (II B) ∑ Type III: Slipping at the femoral neck, resulting in coxa vara or coxa valga with severe anteversion or retroversion (III A) or pseudarthrosis of the femoral neck (III B) ∑ Type IV: Destruction of the femoral head and neck, with a small medial remnant of the neck (IV A), or complete loss of the femoral head and neck and no articulation of the hip (IV B) Forlin and Milani described a simple classiϐication system for sequelae of septic arthritis of the hip in children [83]. In this: ∑ Type I: Reduced hips, with head preserved (I A) and head absent (I B) ∑ Type II: Dislocated hips, with head preserved (II A) and head absent (II B) They found limb shortening of only 2–5 cm in stable hips and up to 14 cm shortening in unstable hips.

3.10.3.1 Treatment options for Hunka type I These hips have minimal avascular insult and have either normal femoral heads or slight coxa magna. They are well contained and do not require any treatment. In these patients if signs of AVN of the CFE are present, in the form of irregularity or speckling of the

47

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Septic Arthritis of the Hip in Children

epiphysis or a delay in the appearance of the epiphysis, abduction splints should be given and the child carefully followed up with serial radiographs.

3.10.3.2 Treatment options for Hunka type II In type II A, there is AVN of the physis with progressive coxa vara or coxa valga. There may be torsional deformity of the neck with increased anteversion or retroversion. In coxa vara, valgus osteotomy has to be performed with additional pelvic procedures to keep the head contained. These corrective osteotomies tend to remodel and the deformities can recur. In these situations the femoral and pelvic osteotomies may have to be repeated. El Tayeby reported good outcomes in 13 of 16 hips in which tailored osteochondroplasty of the femoral heads was done to ϐit into the acetabulum, in addition to the required acetabuloplasty in type II hips [84]. In selective cases osteochondroplasty is useful in pre-adolescent children in improving the range of movement and pain [85]. In type II B, there is premature closure of the physis and hence there is coxa breva, shortening of the limb and trochanteric overgrowth. Early trochanteric epiphyseodesis, or in established cases distal transfer of the trochanter, has to be carried out. Contralateral distal femoral epiphyseodesis if shortening is minimal or lengthening of the affected limb may be necessary to equalise the limb length.

3.10.3.3 Treatment options for Hunka type III In type III, there is involvement of the femoral neck probably due to osteomyelitis of the femoral neck, with complete slipping of the epiphysis. There is coxa vara with pseudarthrosis of the femoral neck. These patients will require valgus osteotomy with or without bone grafting (Fig. 3.9C). The pseudarthrosis is a difϐicult problem to treat and may not respond to bone grafting. Hunka reported unsatisfactory results in his group of patients [81], but Johari et al. reported healing of pseudarthrosis in all their patients [86]. Early corrective osteotomy and restoration of the neck shaft angle are vital in achieving good results.

Sequelae of Septic Arthritis of the Hip in Children

(A)

(B)

(C)

Figure 3.9 (A) A 2-year-old child with type III postseptic deformity. (B) Arthrogram showing the presence of capital epiphysis and pseudarthrosis. (C) 1-year post-operative radiograph showing a well-contained hip and healing of pseudarthrosis, following valgus osteotomy.

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Septic Arthritis of the Hip in Children

3.10.3.4 Treatment options for Hunka types IV and V These are the hips which have been most severely affected with loss of the entire head and neck or the head alone. The remaining part of the femoral neck may be subluxed or dislocated. There will be shortening of the limb and Trendelenburg’s gait. These patients may have several other radiographic ϐindings, like premature closure of the triradiate cartilage, severe dysplasia of the acetabulum, a false acetabulum and a high-riding trochanter. Several procedures have been described by various authors for these deformities over the past 80 years. None of these procedures gives consistent predictable results. Choi reported only 4 satisfactory results out of 13 hips in Choi type IV, which is similar to this group, managed by three different methods [82]. The best results he obtained were with trochanteric arthroplasty. Mathias Tedus reported a new trochanter-splitting osteotomy with a 17-year follow-up in a single case with good results [87]. Betz et al. reported a long-term study of over 40 years on 28 patients, and found that there were two groups of patients, depending on the age at which they were affected, the infantile and the older group. The infantile group had more movements, and stiffness was present only in the operated group. They advised to correct only the limb length difference and refrain from reconstructing the hip. The older age group developed a stiff hip and had severe ipsilateral knee pain as they got older. The authors advised to preserve whatever hip movements this group of patients had and realign the limb through osteotomies [88]. It is not really possible to maintain reduction with the small remnant neck in type IV hips, and hence they should be treated like type V hips. The main problems in this group are shortening of the limb and awkward gait due to that and an unstable proximal femur. Several procedures have been described to stabilise the proximal femur. In trochanteric arthroplasty, the cartilaginous apophysis of the greater trochanter is placed inside the acetabular cavity and maintained with varus osteotomy of the proximal femur. The abductor insertion is detached from the trochanter and reattached on to the proximal femur (Fig. 3.10A–D). The earlier this procedure is done, the better, as the remodelling of the new femoral head appears to be better. The disadvantage is that the varus created in the proximal femur can remodel, and the head can drift out of the

Sequelae of Septic Arthritis of the Hip in Children

acetabulum. In such cases the varus osteotomy has to be repeated. Trochanteric arthroplasty appears to give the best results in these terrible hips [82, 89–91]. The important aspect is to perform the surgery at a very young age, even as young as 1 year, since children operated above the age of 4 to 6 years do poorly [92, 93].

(A)

(B)

(C)

(D)

Figure 3.10 (A) Radiograph of a 3-month-old child with postneonatal septic arthritis showing a dislocated hip with proximal femoral osteomyelitis. (B) Attempts at closed reduction were not successful. Arthrogram at 1 year showed absence of the head and neck of the femur. (C) Subtrochanteric varus osteotomy and trochanteric arthroplasty were done. (D) 6-year follow-up radiograph showing a contained hip. The child had slight shortening and a near-normal gait.

Another procedure described to stabilise the hip is done by sagittally splitting the proximal femur and placing the medial part into the acetabulum by producing an incomplete fracture in the medial cortex. The gap between the two halves is ϐilled by iliac crest graft, either vascularized [94] or nonvascularized [95, 96]

51

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Septic Arthritis of the Hip in Children

(Fig. 3.11). All of these procedures may have to be augmented with a pelvic osteotomy like a Dega, shelf or Chiari osteotomy to improve the coverage.

Figure 3.11

Harmon’s procedure [96].

3.10.3.5 Ilizarov’s reconstruction Ilizarov’s hip reconstruction for postseptic instability includes valgus and extension osteotomy of the proximal femur, which places the proximal femur against the pelvis, thereby giving some stability and also improving the mechanical efϐiciency of abductor muscles. This is combined with another osteotomy at a more distal level for realignment and lengthening [97] (Fig. 3.12). This procedure addresses Trendelenburg’s gait and shortening, which are the problems in type IV and V hips. When performed in younger patients, remodelling at the proximal osteotomy site and recurrence of limb length discrepancy should be expected, and the procedure may have to be repeated [98]. There is an argument for leaving these severely affected hips alone, as the results are not satisfactory consistently, and simply observe them.

Sequelae of Septic Arthritis of the Hip in Children

Figure 3.12 Ilizarov’s reconstruction. Proximal valgus extension osteotomy and distal lengthening and realignment [97].

Most of them do not have pain till much later in life. Total hip replacement can be done for pain in their ϐifth or sixth decades (Fig. 3.13A,B).

3.10.4

Role of Arthroscopy

Hip arthroscopy can be used to treat sequelae of septic arthritis of the hip in adolescents. Arthroscopic osteochondroplasty can be done in type II hips to improve the range of movement and decrease the impingement pain [99].

53

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Septic Arthritis of the Hip in Children

(A)

(B)

Figure 3.13 (A) A 45-year-old lady with type V hip presented with pain. (B) 10 years postcemented total hip replacement.

The problems related to sequelae of septic arthritis of the hip are extremely varied. It can range from minor limb length discrepancy, requiring guided growth in the contralateral limb, to complete destruction of the head and neck of the femur, requiring major reconstruction. In severe type IV and V hips, the treatment recommendations have not been standardised, and mostly surgical results are not satisfactory. Therefore whatever procedure is planned and done should be regarded as a measure that temporarily improves function and delays deϐinitive procedures that are reserved for adults [93, 100]. The treatment plan has to be individualised to the patient.

References

Acknowledgement I acknowledge Ms. S. Rajarajesshvare for creating the illustrations in this chapter.

References 1. Smith T. On the acute arthritis of infants. St Bartholowmews Hospital Reports, 1874; 10:198–204. 2. Gillespie R. Septic arthritis of childhood. Clin Orthop Relat Res, 1973; (96):152–159. 3. Wilson NI, Di Paola M. Acute septic arthritis in infancy and childhood: 10 years’ experience. J Bone Joint Surg B, 1986; 68(4):584–587. 4. Peltola H, Paakkonen M, Kallio P, et al. Prospective, randomized trial of 10 days versus 30 days of antimicrobial treatment, including a short term course of parenteral therapy, for childhood septic arthritis. Clin Inf Dis, 2009; 48:1201–1210. 5. Kocher MS, Mandiga R, Murphy JM, et al. A clinical practice guideline for treatment of septic arthritis in children. J Bone Joint Surg, 2003; 85A:994–999. 6. Nunn TR, Cheung WY, Rollinson PD. A prospective study of pyogenic sepsis of the hip in childhood. J Bone Joint Surg B, 2007; 89(1):100– 106. 7. Qafur OA, Copley LA, Hollnig ST, et al. The impact of the current epidemiology of pediatric musculoskeletal infection on evaluation and treatment guidelines. J Pediatr Orthop, 2008; 28:777–785. 8. Cieslak TJ, Rainik M. Fetal breech presentation predisposes to subsequent development of septic arthritis of the hip. Pediatr Infect Dis J, 2005; 24(7):650–652. 9. Yegupsy P, Bar-Zir Y, Howard CB, Dugan R. Epidemiology, etiology and clinical features of septic arthritis in children younger than 24 months. Arch Paed Adoles Med, 1995; 149:537–540. 10. Lary CB, Peek AC, Majolo Q. The incidence of septic arthritis in Malawian children. Int Orth, 2005; 29:195–196. 11. Narang A, Mukhopadhyay K, Kumar P, Bhakoo ON. Bone and joint infection in neonates. IJP, 1998; 65(3):461–464. 12. Al Saadi MM, Al Zamil FA, Bokhary NA, Al Shamsan LA, Al Alola SA, Al Eissa YS. Acute septic arthritis in children. Pediatr Int, 2009; 51:377– 380.

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13. Nelson JD, Koontz WC. Septic arthritis in infants and children; a review of 117 cases. Paediatrics, 1966; 38:966–971. 14. Nade S, Robertson FW, Taylor TKF. Antibiotics in the treatment of acute osteomyelitis and acute septic arthritis in children. Med J Aust, 1974; 2:703–705. 15. Bennett OM, Namvak SS. Acute septic arthritis of hip joint in infancy and childhood. Clin Orthop Relat Res, 1992; 281:123–132. 16. Mc Carthry JJ, Dormans JP, Kozim SH, Pizzutillo PD. Musculoskeletal infections in children. Basic treatment principles and recent advancements. J Bone Joint Surg, 2004; 86A:850–863. 17. Ogden JA. Changing patterns of proximal femoral vascularity. J Bone Joint Surg, 1974; 56A:941–950. 18. Perlman MH, Patzakis MJ, Kumar PJ, Holtom P. The incidence of joint involvement with adjacent osteomyelitis in pediatric patients. J Pediatr Orthop, 2000; 20:40–43. 19. Chacha PB. Suppurative arthritis of the hip joint in infancy. J Bone Joint Surg A, 53A:538–544. 20. Frederiksen B, Christiansen P, Knudsen FU. Acute osteomyelitis and septic arthritis in the neonate, risk factors and outcome. Eur J Ped, 1993; 152:577–580. 21. Samora JB, Klingele K. Septic arthritis of the neonatal hip: acute management and late reconstruction. J Am Acad Orthop Surg, 2013; 21:632–641. 22. Cieslak TJ, Rajnk M. Fetal breech presentation predisposes to subsequent development of septic arthritis of the hip. Pediatr Infect Dis J, 2005; 24(7):650–652. 23. Caroni D, Cherkaoui A, Ferey S, et al. Kingella Kingae osteoarticular infections in young children: clinical features and contribution of a new speciϐic real time PCR assay to the diagnosis. J Pediatr Orthop, 2010; 30:301–304. 24. Howard AW, Viskontas D, Sabbagh C. Reduction in osteomyelitis and septic arthritis related to Haemophilus inϐluenzae type B vaccination. J Pediatr Orthop, 1999; 19:705–709. 25. Schneider L, Ehlinger M, Stanchina C, Giacomelli M-C, Gicquel P, Karger C, Clavert J-M. Salmonella enterica subsp. arizonae bone and joints sepsis. A case report and literature review. Orthop Traumatol Surg Res, 2009; 95:237–242. 26. Abdul Halim AR, Norhamdan Y, Ramliza R. A child with septic arthritis of hip: a rarely encountered cause. Med J Malaysia, 2011; 66(2):154– 155.

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27. Agnihotri N, Dhingra MS, Gautam, V, Mehta D. Salmonella type septic arthritis of hip: a case report. Jpn J Infect Dis, 2005; 58:29–30. 28. Lavy CBD, Thyoka M, Pitani AD. Clinical features and microbiology in 204 cases of septic arthritis in Malawian children. J Bone Joint Surg B, 2005; 87B:1545–1548. 29. Naithani R, Rai, S, Choudhry, V. Septic arthritis of hip in a neutropaenic child caused by salmonella typhi. J Podiatr Hematol Oncol, 2008; 30:182–184. 30. Gerona JG, Navarra SV. Salmonella infections in patients with systemic lipus erythematous: a case series. Int J Rheum Dis, 2009; 12:319–323. 31. Mukhopadhyay C, Shah H, Vandana KE, Munim F, Vijayan S. A child with Erysipelothrix arthritis- beware of the little known. Asian Pac J Trop Biomed, 2012; 2(6):503–504. 32. Elting JJ, Southwick WO. Acute infantile septic arthritis due to mycobacterium trivial. J Bone Joint Surg, 1974; 56A:184–186. 33. C arrillo-Marquez MA, Hulten KG, Hammerman Wendy RN, Mason EO, Kaplan SL. USA300 is the predominant genotype causing Staphylococcus aureus septic arthritis in children. Pediatr Infect Dis J, 2009; 28(12):1076–1080. 34. Deshpande SS, Taral N, Modi N, Singvakhia M. Changing epidemiology of neonatal septic arthritis. J Orthop Surg, 2004; 12(1):10–13. 35. Sreenivas T, Nataraj AR, Kumar A, Menon J. Neonatal septic arthritis in a tertiary care hospital: a descriptive study. Eur J Orthop Surg Traumatol, 2016; 26(5):477–481. 36. Dohin B, Gillet Y, Kohler R, et al. Paediatric bone and joint infections caused by Panton-Valentine leucocidin-positive Staphylococcus aureus. Pediatr Infect Dis J, 2007; 26:1042–1048. 37. Cohen, D, Stevenson HL, James LA, Sampath JS, Bruce CE. The use of CRP within a clinical prediction algorithm for the differentiation of septic arthritis and transient synovitis in children. J Bone Joint Surg B, 2011; 93B:1556–1561. 38. Levine MJ, McGuire KJ, McGowan KL, Flynn JM. Assessment of the test characteristics of C-reactive protein for septic arthritis in children. J Pediatr Orthop, 2003; 23(3):373–377. 39. Unkila-Kallio L, Kallio MJT, Peltola H. The usefulness of C reactive protein in the identiϐication of concurrent septic arthritis in children who have acute heamatogenous osteomyelitis. J Bone Joint Surg, 1994; 76A(6):848–853.

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40. Wood BP. The vanishing epiphyseal ossiϐication centre; a sequel to septic arthritis of childhood. Radiology, 1980; 134:387–391. 41. Zieger MM, Dorr U, Schulz RD. Ultrasonography of hip joint effusion. Skeletal Radiol, 1987; 16:607–611. 42. Zamzam MM. The role of ultrasound in differentiating septic arthritis from transient synovitis of the hip in children. J Pediatr Orthop B, 2006; 15:418–422. 43. Gordon JE, Huang M, Dobbs M, Luhmann S, Szymanski DA, Schoenecker PL. Causes of false negative ultrasound scans in the diagnosis of septic arthritis of the hip in children. J Pediatr Orthop, 2002; 22:312–316. 44. Kwack K-S, Cho JH, Lee JH, Cho JH, Oh KK, Kim SY. Septic arthritis versus transient synovitis of the hip: gadolinium enhanced MRI ϐinding of decreased perfusion at the femoral epiphysis. AJR, 2007; 189:437– 445. 45. Lee SK, Suh KJ, Kim YW, Ryeom HK, Kim YS, Lee JM, Chang Y, Kim YJ, Kang DS. Septic arthritis versus transient synovitis at MR imaging: preliminary assessment with signal intensity alterations in bone marrow. Radiology, 1999; 211:459–465. 46. Kang MS, Jeon JY, Park SS. Differential MRI ϐindings of transient synovitis of the hip in children when septic arthritis is suspected according to symptom duration. J Pediatr Orthop B, 2020; 29(3):297– 303. 47. Sucato DJ, Schwend RM, Gillespie R. Septic arthritis of the hip in children. J Am Acad Orthop Surg, 1997; 5:249–260. 48. Kocher MS, Zurakowski D, Kasser JR. Differentiating between septic arthritis and transient synovitis of the hip in children: an evidencebased clinical prediction algorithm. J Bone Joint Surg A, 1999; 81:1662– 1670. 49. Luhmann SJ, Jones A, Schootman M, Gordon JE, Schoenecker PL, Luhmann JD. Differentiation between septic arthritis and transient synovitis of the hip in children with clinical prediction algorithms. J Bone Joint Surg, 2004; 86A(5):956–962. 50. Sultan J, Hughes PJ. Septic arthritis or transient synovitis of the hip in children: the value of clinical prediction algorithms. J Bone Joint Surg, 2006; 88A(6):1289–1293. 51. Caird MS, Flynn JM, Leung YL, Millma JE, D’Italia JG, Dormans JP. Factors distinguishing septic arthritis from transient synovitis of the hip in children. J Bone Joint Surg, 2006; 88A(6):1251–1257.

References

52. Scillia A, Cox G, Milman E, Kaushik A, Strongwater A. Primary osteomyelitis of the acetabulum resulting in septic arthritis of the hip and obturator interns abscess diagnosed as acute appendicitis. J Paediatr Surg, 2010; 45:1707–1710. 53. Ogonda L, Bailie G, Wray AR. Acute osteomyelitis of the ileum mimics septic arthritis of the hip in children. Ulster Med J, 2003; 72(2):123– 125. 54. Hartshorn S, Davies K, Anderson JM. Septic arthritis of the pubic symphysis in an 11 year old boy. Paediatr Emerg Care, 2009; 25(5):350–351. 55. Song KS, Lee SM. Peripelvic infections mimicking septic arthritis of the hip in children: treatment with needle aspiration. J Pediatr Orthop B, 2003; 12:354–356. 56. Peckett WRC, Butler-Manuel A, Apthorp A. Pyomyositis of the iliacus muscle in a child. J Bone Joint Surg B, 2000; 82B:103–105. 57. Wong-Chung J, Bagli M, Kaneker S. Physical signs in pyomyositis presenting as a painful hip in children: a case report and review of the literature. J Pediatr Orthop B, 2004; 13:211–213. 58. Falesi M, Regazzoni BM, Wyttenbach M, Wyttenbach R, Bianchetti MG, Riavis M. Primary pelvic pyomyositis in a neonate. J Perinatol, 2009; 29:830–831. 59. Kumar A, Anderson D. Primary obturator externus pyomyositis in a child presenting as hip pain: a case report. Paediatr Emerg Care, 2008; 24(2):97–98. 60. Garcia-Mata S, Hidalgo-Ovejero A, Estaun JE. Primary obturator muscle pyomyositis in immunocompetent children. J Child Orthop, 2012; 6:205–215. 61. Al-Zaiem MM, Bajuifer SJ, Fattani MO, Al-Zaiem FM. Bilateral iliopsoas abscess associated with right hip septic arthritis in a neonate. Saudi Med J, 2014; 35(7):743–746. 62. Journeau P, Wein F, Popkov D, Philippe R, Haumont T, Lascombes P. Hip septic arthritis in children: assessment of treatment using needle aspiration/irrigation. Orthop Traumatol Surg Res, 2011; 97:308–313. 63. Griffet J, Oborocianu I, Rubio A, Leroux J, Lauron J, Hayek T. Percutaneous aspiration irrigation drainage technique in the management of septic arthritis in children. J Trauma, 2011; 70:377–383. 64. Li YQ, Zhou QH, Liu YZ, et al. Delayed treatment of septic arthritis in the neonate: a review of 52 cases. Medicine, 2016; 95(51):1–5.

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65. Schlung JE, Bastrom TP, Roocroft JH, et al. Femoral neck aspiration aids in the diagnosis of osteomyelitis in children with septic hip. J Pediatr Orthop, 2018; 38(10):532–536. 66. El-Sayed AM. Treatment of early septic arthritis of the hip in children: comparison of results of open arthrotomy versus arthroscopic drainage. J.Child Orthop, 2008; 2:229–237. 67. Sanpera L, Raluy-Collado D, Sanpera-Iglesias J. Arthroscopy for hip septic arthritis in children. Orthop Traumatol Surg Res, 2016; 102(1):87–89. 68. Duman S, Camurcu Y, Ucpunav H, et al. Arthroscopic treatment of acute septic arthritis of the hip joint in pediatric patients aged 10 years or younger. Arthroscopy, 2020; 36(2):464–472. 69. Sabour AF, Alluri RK, Heckmann N, et al. A nationwide analysis of failed irrigation and debridement for pediatric septic arthritis of the hip. J Pediatr Orthop B, 2019; 28(5):470–475. 70. Messina AF, Namtu K, Guild M, et al. Trimethoprim-sulfamethaxazole therapy for children with acute osteomyelitis. Pediatr Infect Dis J, 2011; 30:1019–1021. 71. Calvo C, Nunez E, Camacho M, et al. Epidemiology and management of acute, uncomplicated septic arthritis and osteomyelitis. Pediatr Infect Dis J, 2016; 35(12):1288–1293. 72. Vinod MB, Matussek J, Curtis N, Graham HK, Carapetis JR. Duration of antibiotics in children with osteomyelitis and septic arthritis. J Paediatr Child Health, 2002; 38:363–367. 73. Harel L, Prais D, Bar-ON E, Livini G, Hoffer V, Uziel Y, Amir J. Dexamethasone therapy for septic arthritis in children: results of a randomised double blind placebo-controlled study. J Pediatr Orthop, 2011; 31(2):211–215. 74. Lee SC, Shim JS, Seo SW, Lee SS. Prognostic factors of septic arthritis of hip in infants and neonates: minimum 5-year follow up. Clin Orthop Surg, 2015; 7:110–119. 75. Agarwal A, Vimal Kumar KH. Suppurative arthritis of hip in a walking child: Effect of patient’s age, delay in surgical drainage, and organism virulence. J Orthop Surg (Hong Kong), 2020; 28(1). 76. Sukswai P, Kovitranitcha D, Thumkunanon V, et al. Acute haematogenous osteomyelitis and septic arthritis in children: clinical characteristics and outcomes study. J Med Assoc Thai, 2011; 94(Suppl 3):S209–S216. 77. Akinyoola AL, Obiajunwa PO, Oginni LM. Septic arthritis in children. WAJM, 2006; 25(2):119–123.

References

78. Lack CH. Chondrolysis in arthritis. J Bone Joint Surg, 1959; 41B(2):384– 387. 79. Munting TW, Hoffman EB, Hastings CJ. Avascular necrosis following septic arthritis of the hip in children. J Bone Joint Surg B, 2002; 84B(Suppl):80. 80. Johari AN, Dhawale AA, Johari RA. Management of post septic hip dislocations when the capital femoral epiphysis is present. J Pediatr Orthop B, 2011; 20:413–421. 81. Hunka L, Said SE, Mackenzie DA, Rogala EJ, Cruess RL. Classiϐication and surgical management of the severe sequelae of septic hips in children. Clin Orthop Relat Res, 1982; 171:30–36. 82. Choi IH, Pizzutillo PD, Bowen R, Dragann R, Malhis T. Sequelae and reconstruction after septic arthritis of the hip in infants. J Bone Joint Surg, 1990; 72A(8):1150–1165. 83. Forlin E, Milani C. Sequelae of septic arthritis of the hip in children. A new classiϐication and a review of 41 hips. J Pediatr Orthop, 2008; 28:524–528. 84. El-Tayeby HM. Osteochondroplasty of the femoral head in hip reconstruction for type II late sequelae of septic arthritis: preliminary report. J Child Orthop, 2008; 2:431–441. 85. Shin SJ, Choi IH, Cho TJ, et al. Unusual osteocartilagenous prominence or bump causing femuro acetabular impingement after septic arthritis of hip: a report of 2 cases in pre adolescence. J Pediatr Orthop, 2009; 29(5):459–462. 86. J ohari AN, Hampannavar A, Johari RA, Dhawale AA. Coxa vara in post septic arthritis of the hip in children. J Pediatr Orthop, 2017; 26(4):313–319. 87. Tedeus M, Heimkes B. Longterm results after femoral head substitution in post infectious aplasia of the femoral head. J Child Orthop, 2011; 5:351–355. 88. Betz RR, Cooperman DR, Wopperer JM. Late sequelae of septic arthritis of the hip in infancy and childhood. J Pediatr Orthop, 1990; 10(3):365– 372. 89. Benum P. Transposition of the apophysis of the greater trochanter for reconstruction of the femoral head after septic hip arthritis in children. Acta Orthop, 2011; 82(1):64–68. 90. Dobbs MB, Sheridan JJ, Gordon JE, Corley CL, Szymanski DA, Schoenecker PL. Septic arthritis of the hip in infancy: long term follow up. J Pediatr Orthop, 2003; 23(2):162–168.

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91. Ferrari D, Libri R, Donzelli O. Trochanteroplasty to treat sequelae of septic arthritis of the hip in infancy. Case series and review of the literature. Hip Int, 2011; 21(06):653–656. 92. Wang EB, Ji SJ, Zhao Q, Zhang LJ. Treatment of severe sequelae of infantile hip sepsis with trochanteric arthroplsty. J Pediatr Orthop, 2007; 27(2):165–170. 93. Choi IH, Shin YW, Chung CY, et al. Surgical treatment of the severe sequelae of infantile septic arthritis of the hip. Clin Orthop Relat Res, 2005; (434):102–109. 94. Cheng JCY, Aguilar J, Leung PC. Hip reconstruction for femoral head loss from septic arthritis in children: a preliminary report. Clin Orthop Relat Res, 1995; (314):214–224. 95. Li X-d, Chen B, Fan J, Zheng C-y, Liu D-x, Wang H, Xia X, Ji S-j, Du S-x. Evaluation of the modiϐied Albee arthroplasty for femoral head loss secondary to septic arthritis in young children. J Bone Joint Surg A, 2010; 92:1370–1380. 96. Harmon PH. Surgical treatment of the residual deformity from suppurative arthritis of the hip occurring in young children. J Bone Joint Surg, 1942; XXIV(3):576–585. 97. Ilizarov GA. Hip dislocations. In Transosseous Osteosynthesis: Theoretical and Clinical Aspects of Regeneration and Growth of Tissue. Springer, Berlin, 1992; pp. 701–705. 98. Rozebruch R, Paley D, Bhave A, Herzenberg JE. Ilizarov hip reconstruction for the late sequelae of infantile hip infection. J Bone Joint Surg, 2005; 87A(5):1007–1018. 99. Lim C, Cho TJ, Shin CH, Choi IH, Yoo WJ. Functional outcomes of hip arthroscopy for pediatric and adolescent hip disorders. Clin Orthop Surg, 2020; 12(1):94–99. 100. Wada A, Fujii T, Takamuva K, et al. Operative reconstruction of the severe sequelae of infantile septic arthritis of the hip. J Pediatr Orthop, 2007; 27:910–914.

Chapter 4

Developmental Dysplasia of the Hip

Munis Ashrafa and Senthilnathan Sambandamb aYenepoya Medical College Hospital, University Road, Deralakatte, Karnataka 575018, India bBoston VA Medical Center, USA [email protected], [email protected]

This chapter encompasses a detailed description of the classiϐication systems used in the assessment of developmental dysplasia of the hip (DDH).

4.1 Graf Classification of DDH Using Ultrasonography Reinhard Graf from Austria in 1980 (Table 4.1) published his work in two parts to establish that ultrasound is an effective screening tool for diagnosing dislocated hips [1, 2]. A group-wise classiϐication was tabulated, and treatment recommendations made.

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Copyright © 2022 Jenny Stanford Publishing Pte. Ltd.

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64

Graf classification of DDH

Graf hip type

Descriptive term

Alpha angle

Beta Angle

Age (years)

Recommended treatment

Equivalent radiographic description

Ia

Normal

>=60

>70

Any

No

Concentrically reduced

Ib

Normal

>=60

12 weeks

Yes

Concentrically reduced

III c

Dysplastic with risk for dislocation

43–49

77

Any

Yes

Subluxated

Any

Yes

Dislocated

III a

Decentered

40 mm in size were revised within 10 years as compared to 5.7% for those with head size ζ28 mm [42].

5.5.6.2 Advantages Boundary and elastohydrodynamic lubrication is better than boundary lubrication alone in metal-on-polyethylene articulations. This bearing has a low volumetric wear rate (40–100 times lesser) than metal-on-polyethylene bearings [7]. Large heads can be used with thinner liners, which reduces dislocation rates. Hip resurfacings are known to allow patients an early return to high-impact activities, with the added advantages of preserved bone stock and easy conversion to THA [108].

5.5.6.3

Disadvantages

Although the volumetric wear is low, the number of particles generated is much higher (13–500 times) with a smaller particle size (average 42 nm) as compared to polyethylene debris (21 mm). The metallic debris can have local and systemic effects [109, 110]. Generated particles have a local inϐlammatory response (aseptic lymphocyte dominated vasculitis-associated lesions [ALVALs]), pseudotumor formations with tissue destruction, local necrosis, metallosis (Fig. 5.14B,C), bone resorption and a range of clinical symptoms often requiring complex and challenging revision surgery [111, 112].

Figure 5.14 Hutchison.

Problems with metal-on-metal bearings. Courtesy of Jim

107

108

Bearing Materials in Total Joint Arthroplasty

Cobalt and chromium ion levels are a main clinical concern, although a variety of ions like Ti, Va, Ni, Mo and Al have been shown to be released in systemic circulation. These are excreted by renal circulation; however, no adverse effects on the kidney have been reported [113]. Chromosomal translocations and aneuploidy have been reported in patients with MoM arthroplasties [114]; however, a correlation with metal ion concentrations has yet to be established. Data analysis from the British Joint Registry [115] and the Swedish Cancer Registry [116] have yielded reassuring results and report no associations between metal ion concentrations and the risk of cancer. A Finnish registry review of 10,000 MoM arthroplasties similarly reported no risk of cancer [117]. Mother-to-fetus transmission across the placenta is noted in reduced quantities; however, no adverse effects on the fetus or child growth have been identiϐied [118, 119]. The risks of polyneuropathy, polycythemia, hypothyroidism, cognitive dysfunction, etc., have been variably reported in the literature. Fatal cardiomyopathy [120] in MoM patients is a serious complication. Patients with cardiac or neurologic complications relatable to serum ion levels should be offered revision surgery. Systemic symptoms progressively improve and metal ion levels in serum decline upon removal of the implants, highlighting the beneϐit of timely revision surgery [121]. In light of the various complications associated with serum metal ions, the Medical and Health products Regulatory Agency (MHRA, UK) in 2010 banned MoM arthroplasties, advising surveillance for serum metal ion levels with a threshold of 7 ppb (for both Co and Cr) set to classify patients at high risk for complications. The recently updated (2017) guidance advises magnetic resonance imaging (MRI) scans and ultrasounds to have more clinical signiϐicance in symptomatic patients than isolated serum levels. Rising blood ion levels can potentially predict soft-tissue reactions in asymptomatic patients [122]. In brief, the management guidelines highlight that the resurfacing group (all females, males with head size ζ48, all depuy ASR hips) and the THR group (femoral heads η 36) need to be followed up annually with Oxford hip questionnaires and blood metal ion levels. An MRI/ultrasound is warranted if a dip in scores

Summary

is observed, followed by a clinically advised decision on revision, if necessary. The reader is referred to the guidance document in the references for full details on the algorithm for the management of these patients [122].

5.6

Discussion

Yin et al. conducted a systematic review of 40 RCTs with 5321 patients, reporting survivorship or revision rates amongst the various bearing combinations (MoHXLPE, CoHXLPE, CoC, MoUHMWPE, CoUHMWPE). They concluded that there was no difference in survivorship among CoC, CoUHMWPE, CoHXLPE and MoHXLPE groups. These bearing combinations were reported to be superior when compared to MoUHMWPE and MoM groups. This is consistent with the encouraging data available from the British and Australian joint registries favouring the use of HXLPE over conventional polyethylene. Furthermore, the registries also demonstrate minimal differences in the ceramic and metal combinations with HXLPE [123]. Wyles et al. in their systematic review similarly reported no difference in the short- to mid-term survivorship of MoHXLP, CoC and CoHXLP in people younger than 65 years [124]. Zagra et al. have made suggestions for implant choices to be made for different age groups. CoC bearings (with a 32–36 mm head) for younger individuals (80%) and allows full communication between the pores. Thirty cases who underwent surgery for early femoral head osteonecrosis were selected. Initially, the bone of the greater trochanter was removed with a circular bone removal apparatus and gradually the hole was reamed. A ϐinal 3Dprinted titanium metal trabecular implant of the same diameter was considered. The pores of the 3D-printed titanium trabecular metal implant were ϐilled with autologous cancellous bone graft harvested from the greater trochanter or bone allograft harvested in the area of the femoral head necrosis in the femoral head. Lastly, the implant was placed in the defect created after determining the correct insertion depth. Results indicated that the 3D-printed titanium trabecular bone metal may not completely stop the progression of femoral head osteonecrosis but may delay its progression [51].

135

136

3D Printing

6.6.3 Femoro-Acetabular Impingement Cam-type femoro-acetabular impingement (FAI) can be managed by doing osteochondroplasty for removing the excess impinging bone from the head–neck junction of the femur. Verma et al. reported a case of Cam-type FAI in an 18-year-old male who underwent surgical treatment by osteochondroplasty. CT-based virtual surgical planning was performed to make femoral head and neck jigs, which were 3D-printed and used during surgery to guide for suitable excision of bone at the femoral head–neck junction. Authors found that their customised jigs were quite accurate and useful for the purpose [52]. Wong et al. showed that 3D models of the patient can be used in pre-operative planning to determine the extent and location of osteoplasty for FAI surgery and analysed retrospective data of 10 consecutive cases with a clinical diagnosis of FAI. Three-dimensional models of each affected hip were printed to scale from CT data. Two orthopaedic surgeons evaluated every case in a routine fashion. The role of the 3D models in affecting the planned osteoplasty was then elucidated. Proportions of osteoplasty changes ranged from 20% to 55% at femoral positions (greatest at lateral and depth positions) and 35%–75% at acetabular positions (greatest at anterior and depth positions). Greater osteoplasty changes were there in cases with alpha angles of 60° or more and without a radiographic crossover sign. No difference in the proportion of osteoplasty changes was found when stratifying by lateral centre edge angle and coxa profunda. The planned osteoplasty changed for at least one reader in 9/10 (90%) femurs and 10/10 (100%) acetabula. Usage of 3D models in pre-operative planning can change both the extent and the location of planned osteoplasty for FAI surgery, and it is particularly important in patients with alpha angles of 60° or more and without a radiographic crossover [53].

6.6.4

Hip Arthroscopy, FAI and 3D Printing

Bockhorn et al. used 3D printing for patient counselling, preoperative planning and resident education for patients undergoing hip arthroscopy or hip preservation surgery. Outcomes of hip preservation surgery depend upon the correction of morphological abnormalities, which may be optimally visualised/felt using 3D

Applications in Hip Arthroplasty

models. To judge the utility of 3D-printed models for patient and trainee education and to elucidate its beneϐits for pre-operative planning in hip preservation surgery, 16 cases with hip pathology were selected. CT data were used to generate 3D models. Out of the 16 included cases, 12 underwent a total of 13 hip arthroscopies. Intra-operatively, 11 cam lesions, 8 pincer lesions and 12 anterior inferior iliac spine (AIIS) lesions were decompressed. All 12 hips also had chondrolabral pathology, necessitating repair with an average traction time of 47.1 min. There was one case with FAI who suffered a traumatic hip dislocation 7 months post-operatively which led to repeat surgery. The exact cause of the dislocation was unknown. The patient, however, was found to have a thin capsule during the ϐirst surgery. A plication was performed during the hip arthroscopy. Out of the 12 cases who underwent surgery, 6-week post-operative radiographs revealed good cam correction without any fracture or dislocation. All cases reported improvement or resolution of hip pain. Intra-operative complications, infection, neuropraxia, hip dislocation, deep vein thrombosis (DVT) and pulmonary embolism (PE) were all absent. Likert-style questionnaires were provided to 10 hip preservation surgeons, 11 orthopaedic surgery residents and 10 patients. All residents strongly agreed or agreed that the 3D hip models helped them in understanding patients’ pathoanatomy. All but one patient also agreed that they helped in understanding the treatment plan. Surgeons agreed that though they do not routinely order 3D models, their usage will improve trainee and patient education and conceptualisation of intricacies of the treatment plan, particularly when treating atypical osseous pathomorphologies. Patients and trainees both agreed that the models improved their educational experience, as the surgeon can directly demonstrate complex morphological abnormalities. As patients better understand their hip disorder, they can better participate in shared treatment decision-making. Trainees can gain a better intuitive understanding of minuate of hip pathologies and their treatment [54].

6.7

Applications in Hip Arthroplasty

Due to the disturbed anatomy of the acetabulum and the proximal femur, adult patients with developmental dysplasia of the hip (DDH)

137

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or sequelae of septic arthritis have leg length discrepancy and will develop secondary osteoarthritis; therefore, total hip arthroplasty (THA) in these patients represents a valuable procedure. THA is, however, challenging in cases of osteoarthritis secondary to DDH or septic hip sequelae because acetabular deϐiciency makes the positioning of the acetabular component difϐicult as normal anatomic landmarks are vague. Care should be taken in adjusting the cup size, inclination, cup anteversion, and coverage. The 3D-printed model may help a surgeon in identifying pelvic structures, assessing the ideal extent of reaming and determining the size of the cup. Wang et al. published a study comparing the clinical data between the use of the 3D printing technique and conventional hip arthroplasty in cases with severe hip deformities. Threedimensional-printed pelvic models and acetabular prosthesis were created for the 3D printing group. No signiϐicant differences were found as compared to the opposite hip in terms of anterior and lateral femoral anteversion, neck shaft angle, of acetabular angles in the 3D printing group. However, the mean anteversion angles of the ipsilateral and contralateral hip on two sides in the conventional arthroplasty group were signiϐicantly different, indicating that the 3D printing group was closer to the native anatomy. Also, the time to weight-bearing in the 3D printing group was lesser than that for the conventional arthroplasty group, and the follow-up Harris scores were higher in the 3D printing group, revealing that 3D-printed prostheses allow for better coordination with human biomechanics [55]. Xu et al. used CT-based, individualIsed 3D-printed models to plan the placement of the acetabular cup so that a surgeon could identify pelvic structures, assess the ideal reaming extent and determine the correct cup size [56]. Zhang et al. used the 3D printing technique (computer-assisted, patient-speciϐic navigational templates in metal-on-metal hip resurfacing arthroplasty) in 22 DDH cases and had precise implant positioning with similar results [57]. Won et al. performed THA with the help of a rapid prototyping model on 21 complex hips; all operations were completed successfully, and the acetabular components were within 2 mm of the predicted size in 17 hips. All acetabular components and femoral stems had bone ingrowth and were stable at the ϐinal follow-up (mean: 35.5 months), without any osteolysis or wear [58].

Applications in Hip Arthroplasty

6.7.1

Revision Hip Arthroplasty

Zerr et al. report usage of 3D printing technology in a case of revision THA. They printed a real-size 3D model of the affected pelvis and femur for trialing of the acetabular component for determining the cup size, position, screw placement and need for reaming. Postoperative radiography revealed that the prosthesis was stable with multiple screw ϐixation [59]. Hughes et al. created a hemipelvis model and a full pelvic model to conduct complex revision hip replacement in two cases. Life-size models allowed accurate surgical simulation; the pre-operative cup, augment and buttress sizing as well as cage templating and screw trajectory optimisation led to improved accuracy and reduced the risk of intra-operative neurovascular damage [60]. Bagaria et al. did a multicentric study involving 5 surgeons and created 3D-printed biomodels for 50 surgical cases, including pelvic fractures (11), periarticular fractures (24), complex primary (7) and revision replacement surgeries (8), using CT scan data and used these for understanding pathoanatomy and conducting simulated surgery. All models were sterilised for intra-operative referencing. Pre-operative planning, pre-operative implant selection, surgical rehearsal, surgical simulation, intra-operative referencing, navigation and inventory management were all fulϐilled, besides better surgical accuracy and reduced surgical time. All researchers agreed that they would recommend it to other surgeons, besides indicating their enthusiasm for personal use [61]. Li et al. used custom cages in a group of 26 patients with severe (Paprosky IIIB) bone defects in revision THA and found that the individualised cages resulted in restoration of a more normal hip centre, improved Harris hip scores and low risk of complications [62]. Mao et al. used custom cages for revision hip arthroplasty in 23Ԝcases with massive acetabular deϐiciency (Paprosky type III); 22 of the 23 cages (including 1 re-revision case) were stable at the ϐinal follow up, and the average Harris hip score improved from 39.6 before surgery to 80.9 [63].

6.7.2 Custom Prosthesis In the past, patient-speciϐic prostheses with complex shapes were difϐicult to access because of the limitations of the traditional

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manufacturing technology. Three-dimensional printing technology has provided a solution. It can be used to easily create anatomyconforming prostheses of any shape with a porous metal surface, allowing osseointegration at the bone–implant junctions [64]. Custom implants are indicated if patients’ bony geometries fall outside the range of standard implants or if improved surgical results are expected due to a better ϐit between implants and the patients’ anatomy. Mostly they are used for revision THA (cases with marked acetabular deϐiciency) and tumour surgery. Several studies analysed the acetabular defect in detail to reconstruct the acetabulum using a custom-made trabecular titanium implant which matches the anatomy of the deϐicient acetabulum, considering the patient’s bone quality to achieve primary implant stability [65–72]. Custom-made triϐlanged acetabular components (CTACs) were created to achieve primary implant stability, even in cases with extreme acetabular bone loss, by maximising host bone contact and by three ϐlanges that ϐit the ilium, ischium and pubic bones. CTAC implants are based on 3D models produced from the patient’s CT scans. The implant proposal includes case-speciϐic screw positions based on bone quality and drill guides to achieve the planned position and considers individual hip biomechanics. Medial side of CTAC implants may be made with a porous defectϐilling scaffold to allow osteointegration. De Martino et al., in a systematic review of 17 articles assessing the clinical results of 579 CTACs, found all-cause revision-free survivorship to be 82.7% and an overall complication rate of 29%. Dislocation and infection were the most common complications, with an incidence of 11% and 6.2%, respectively, due to the extensive approach and the poor quality of soft tissues in multiply-operated cases [72]. However, since they are only used for cases with signiϐicant acetabular bone loss or pelvic discontinuity, CTACs are an efϐicacious treatment option and have future potential.

6.7.3 Patient-Specific Instrumentation Patient-speciϐic instrumentation (PSI) helps guide the accurate positioning of components during hip arthroplasty and is an alternative to navigation. PSI uses CT or MRI to plan surgery in a

Applications in Orthopaedic Oncology

virtual 3D environment. One can plan the position and orientation of the prosthesis relative to a standard frame of reference and execute the plan using simple intra-operative patient-speciϐic guides. Acetabular guidance systems optimise the cup size, implant medialisation, anteversion and inclination, whereas femoral guidance systems optimise the stem size and alignment, offset, leg length and stem version. Small et al. compared 18 cases undergoing THA with conventional instrumentation and 18 cases undergoing THA with PSI in an RCT and saw a statistically signiϐicant difference in the version of the acetabular component. Long-term functional outcomes or survival are still controversial [73, 74].

6.8 Applications in Orthopaedic Oncology 6.8.1 Tumour Sallent et al. performed a cadaveric study on the accuracy of PSIguided osteotomies versus the conventional technique in pelvic tumour resection and noticed that computer-assisted planning and PSI improved accuracy, bringing osteotomy results closer to preoperative planning parameters [75]. A 3D model of a pelvis with a large chondrosarcoma helped in the production of customised osteotomy guides, which aided tumour resection with adequate margins [76]. Wong et al. described a workϐlow for performing a partial acetabular resection in a case with pelvic chondrosarcoma and reconstruction with a custom pelvic implant in a single surgery. A CAD custom implant was prefabricated using 3D printing technology and was also evaluated biomechanically. A multiplanar bony resection was then planned in silico and 3D-printed PSI was used for the same planned resection. The histology showed a clear resection margin. The errors of the achieved resection and implant position were deviating (1–4Ԝmm) from the planning [77]. Holzapfel et al. used both customised prostheses and PSI for 56 patients with periacetabular tumours. A 3D model of the pelvis was fabricated according to data obtained by high-resolution computed tomography (HRCT), and special prostheses and osteotomy guides were designed on the basis of the planned cuts. Out of 56 patients, 10 experienced local recurrence after a mean of 8.9Ԝmonths [78].

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Three-dimensional printing technology is emerging as an alternative because of acceptable cosmesis, immediate stability and the possibility of rapid recovery, as well as early weightbearing activity. Recently, 3D-printed prostheses have been used for hemipelvic reconstruction and have obtained good short-term functional results. Liang et al. reported 35 patients who underwent pelvic tumour resection and reconstruction with a 3D-printed prosthesis. Three patients had iliac prosthesis, 12 had standard hemipelvic prosthesis and 20 had a screw-rod-connected hemipelvic prosthesis. At mean 20.5 months follow-up, 25 survived without evidence of disease, 5 were alive with disease and 5 died from metastatic disease. For the surviving cases, the mean Musculoskeletal Tumor Society score was improved [79]. Wang et al. reported 11 patients with periacetabular malignant bone tumours treated by personalised 3D-printed hemipelvic prosthesis following en bloc resection. At 15.5 months, patients had acceptable functional results without severe complications, except hip dislocation in 2 patients and delayed wound healing in 1 patient. No local tumour recurrence was observed. Reconstruction arthroplasty using 3D-printed pelvic prostheses can facilitate the accurate matching and osseointegration between implants and host bone. Reconstruction arthroplasty using 3D-printed pelvic prostheses provides a promise for patients with peri-acetabular malignant bone tumours [80].

6.8.2

Shepherd’s Crook Deformity

Wan et al. innovated a case-speciϐic osteotomy template to anchor with k-wires onto the most suitable surface of the femur, and then osteotomy was created by using an electric saw along the designed osteotomy line on the template. Ten patients with Shepherd’s crook deformity were enrolled. The neck shaft angle was corrected from a mean value of 88.1° (range: 73°–105°) pre-operatively to a mean value of 128.5° (range: 120°–135°) post-operatively. Threedimensional printing osteotomy templates helped in correction of Shepherd’s crook deformity [81].

Applications in Paediatric Orthopaedics

6.9 Applications in Paediatric Orthopaedics 6.9.1

Slipped Capital Femoral Epiphysis

Fifteen children with slipped capital femoral epiphysis (SCFE), who were treated with three-plane proximal femoral osteotomy (TPFO), were included in Cherkasskiy’s study. Ten cases were treated by one surgeon with or without a 3D model for planning and were compared with ϐive cases treated by two senior partners without any model. Surgical time decreased by 45Ԝmin and 38Ԝmin, respectively, and ϐluoroscopy time decreased by 50% and 25%, respectively, in the model group [82].

6.9.2 Paediatric Hip Fractures Zheng et al. made a drill template using 3D printing technology for putting screws in a locking compression paediatric hip plate (LCPPHP). Using the CT data, the proximal femur model was made by a 3D printer. Fracture reduction and placement of screw in the femoral neck and the LCP-PHP were simulated by the computer. Then a navigation template was made in silico to conform with the proximal femur and was printed out. The guide pins and the screws were inserted with the aid of the navigation template in the operation. Reduced risk of damage to the femoral neck epiphysis, decreased operation time, reduced intra-operative haemorrhage and decreased patients’ radiation exposure during surgery are some advantages [83].

6.9.3

Development Dysplasia of the Hip

Zheng et al. used 3D-printed navigation templates in proximal femoral varus rotation and shortening osteotomy for older children with DDH. Navigation templates were used for 12 DDH patients, while 13 other patients underwent surgery without the navigation template. Ipsilateral and contralateral the femoral varus angle, the rotation angle, and the length of bone to be cut were determined to devise the 3D-printed navigation template. The template-guided group achieved a better outcome: operation time (21.08Ԝmin vs. 46.92Ԝmin),

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number of X-ray exposures (3.92 vs. 6.69) and occurrence of femoral epiphysis damage (0 vs. 0.92) were signiϐicantly decreased [84–86].

6.10 Applications in Plastic Surgery Related to Limbs Soft-tissue mapping–perforator ϐlap surgery is performed routinely for reconstruction of large soft-tissue defects left after injury or a tumour resection. Using CT angiography for pre-operative planning has now allowed the plastic surgeon to ϐind an ideal donor site, ϐlap and perforator vessels for a free ϐlap transfer, facilitating a greater ϐlap success rate and an overall improvement in the clinical outcomes. Going further, 3D anatomical models provide an extra advantage of granular clinical information for the operating surgeon through visual as well as tactile feedback. This technique has been used for planning and performing precise perforator ϐlap reconstruction of soft-tissue defects of ankle left using images of the contralateral ankle for mirroring. Chae et al. nicely illustrated this case, and we will also use it here as an example to understand the concept of mirroring, which is a vital concept for 3D modeling applications in orthopaedics and trauma and plastic surgery.

6.10.1 Illustrative Case Chae et al. described a technique of creating a ‘reverse’ model representing a soft-tissue ankle defect, which was used for planning a perforator-based ϐlap reconstruction (Fig. 6.4) [87]. CT angiography of the forearms (i.e., donor site) and lower limbs (i.e., recipient site) was performed, and the DICOM data ϐile was converted to a CAD ϐile with the help of Osirix software. The 3D image of the contralateral normal ankle was mirrored and superimposed over the image of the side with the soft-tissue defect on the anteriomedial aspect with an exposed ankle prosthesis. With the help of digital subtraction using Magics software (Materialise NV), a ‘reverse’ model representing the ankle soft-tissue defect was made. The involved ankle with the soft-tissue defect as well as the ‘reverse’ model were created with PLA ϐilaments on a Cube 2 printer. It allowed the surgeon to pre-operatively acknowledge the length,

Applications in Plastic Surgery Related to Limbs

width and depth of the free ϐlap that was necessary to be harvested for adequately covering the defect. A 3D-printed anatomical softtissue model has also been used for planning perforator-based ϐlap reconstruction of a sacral soft-tissue defect left after tumour resection [88]. Authors used Osirix software to translate the preoperative sacral CTA data ϐile into a CAD ϐile. Due to lower dimensions allowed in the Cube 2 printer used by the authors (16 cm × 16 cm × 16 cm), the 3D image of the sacral defect was down-scaled in the Cube software. The model still represented the shape and depth of the sacral defect and its relation to the surrounding structures quite accurately.

Figure 6.4 Illustrative case. (A) Soft-tissue right ankle defect. Threedimensional image of the right (pathological) ankle is to be juxtaposed to the ůĞĨƚ;ŶŽƌŵĂůͿĂŶŬůĞ͘;ͿdŚĞůĞĨƚĂŶŬůĞŝƐƌĞŇĞĐƚĞĚͬŵŝƌƌŽƌĞĚ͘;ͿdŚĞůĞĨƚĂŶŬůĞ ŵŽĚĞů;ƌĞŇĞĐƚĞĚͬŵŝƌƌŽƌĞĚͿŚĂƐďĞĞŶƐŚŽǁŶŝŶĂĚŝĨĨĞƌĞŶƚĐŽůŽƵƌ͘;ͿdŚĞůĞĨƚ ĂŶŬůĞ ŵŽĚĞů ;ƌĞŇĞĐƚĞĚͬŵŝƌƌŽƌĞĚͿ ƐƵƉĞƌŝŵƉŽƐĞĚ ŽŶ ƚŽ ƚŚĞ ƌŝŐŚƚ ĂŶŬůĞ͘ ;Ϳ Images subtracted from each other to produce a ‘reverse’ model of the softtissue defect. 3D prints of the right ankle with the defect and the ‘reverse’ model of the soft-tissue defect are then taken on a 3D printer.

6.10.2

Evolving Areas in 3D Bioprinting

LabSkin Creations and the Laboratory of Cutaneous Substitutes (Edouard Herriot Hospital, Lyon) have developed a hydrogel used for skin microextrusion bioprinting, which has been patented. Artiϐicial skin is produced in 0.5-cm-thick, 1 cm2 pieces, and pieces up to 200Ԝcm2 are made on demand. Histological evaluation demonstrates that the skin samples are of good quality, with 100% cellular viability. Full-thickness skin can be obtained within 21 days, as compared to 45 days with traditional tissue engineering techniques. The next focus is on the bioprinting of bone. A unique feature of 3D

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bioprinting is the cellular ink which is used; it can yield precisely shaped grafts. This technique is quite different from classical tissue engineering in which a scaffolding is ϐirst made and then seeded with cells. On a microscopic scale, 3D bioprinting provides a cell-speciϐic environment with a conducive 3D structure (hydrogel contains all the factors required for survival). On a macroscopic scale, 3D bioprinting will allow the making of personalised autologous grafts that perfectly ϐit the tissue defect, thereby facilitating reconstruction success, besides reducing donor site morbidity. One possible limitation is the ability to create a vascular network, and once this is overcome, ‘ready-to-implant’ organs and autologous free ϐlaps with a vascular pedicle will be a reality [89–92].

6.11 Applications in Rehabilitation: PatientSpecific Orthoses and Prostheses Saharan et al. published a 3D-printed lightweight exoskeleton (iGrab) made using twisted and coiled polymer (TCP) muscles, which are lightweight and provide a high power-to-mass ratio, along with enough stroke. Silver-coated nylon threads were utilised to make TCP muscles. Hand orthoses made using various actuation techniques were reviewed by authors, and they presented their design of tendon-driven exoskeletal prostheses with muscles conϐined to the forearm area [93]. Paterson et al. published the use of customised wrist splints manufactured by 3D printing [94]. Patient-speciϐic sockets may be made by 3D printing for customised rehabilitation after lower-limb amputation surgery. They are anatomical and provide higher durability and strength [95–97]. Combination of 3D printing and robotic technologies has allowed the manufacture of functional prosthetic hands [98]. Threedimensional printing allows the creation of lightweight, well-ϐitting and affordable customised prostheses for growing children. Xu et al. treated an 8-year-old child who had a right wrist amputation due to a mincing machine accident. A 3D-printed prosthetic hand was made, and the child was well rehabilitated [99]. After a hand amputation, a myoelectrically controlled hand prosthesis can restore the grasping function. Recently, customised 3D-printed prostheses have come up, and several companies provide personalised 3D-printed arm, hand

Conclusion

and ϐinger prosthetics. Human skin contains a complex network of neurons which relay information about thermal and tactile stimuli to the brain, allowing us to operate in our environment effectively and safely. Printing of biomimetic prosthetics containing layers of different neurons may in future make prosthetic limbs a fully functional (including sensations) body part [100]. Most reports have indicated that 3D-printed custom prostheses provide superior aesthetics in comparison to the traditional wax-based handcrafted prosthetics.

6.12

Reliability of 3D-Printed Models

Some professionals distrust the reliability of 3D printing for clinical use. Zou et al. evaluated the precision and reliability of the stereolithographic appearance of 3D-printed models. CT data for bone/prostheses and models were collected and 3D-reconstructed. The intraclass correlation coefϐicient (ICC) was used for evaluating the degree of similarity between the model and the real bone/ prosthesis regarding several anatomical parameters. No signiϐicant difference was found in the anatomical parameters except the maximum height of long bones. All ICCs were greater than 0.990. Overall, usage of a 3D-printed model for diagnosis and treatment purposes in complex orthopaedic diseases is precise and reliable [101].

6.13

Conclusion

Traditional imaging modalities involve limitation of 2D surface display only (even for 3D-reconstructed images) on a ϐilm or computer screen. Appreciation of the pathoanatomical abnormality involving the hip joint may not be clearly obtained on a 2D screen. A 3D-printed model provides visual and tactile sensation of the impaired and pelvic and femoral anatomy in particular, which brings an improved understanding (which may be difϐicult to appreciate otherwise) and facilitates pre-operative planning. A 3D-printed model facilitates both the patient and the surgeon in developing a higher-level conceptual understanding of the anatomy as well as the procedure and also improves operative planning by allowing

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direct physical interaction with a graspable model of the casespeciϐic anatomy. Until quite recently, the cost of outsourcing usually prevented its widespread acceptance in the surgical practice. Now 3D printing is ϐinding increasing acceptance in almost all surgical disciplines, and orthopaedics is no exception. It aids in precise identiϐication of human anatomy and pathology, improves preoperative planning (enables the pre-operative visualisation and tactile feel of complex articular fractures and gives an opportunity to practice reduction maneuvers pre-operatively, potentially lowering operating time), improves the surgical trainees’ learning experience and also facilitates better patient education. Further, implants, joint prostheses (including customised tumour mega-prosthesis) and orthoses and artiϐicial limbs can be contoured from desired materials based on 3D-printed models and can even be directly 3D-printed, ultimately improving patient care. Three-dimensional bioprinting applications and bench-to-bedside translations are also on the horizon in the future of orthopaedics. We enthusiastically speculate that 3D printing holds the key to the future in orthopaedics and traumatology.

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41. Huang H, Xing W, Huang W, Zeng C. Pararectus approach combined with three-dimensional printing for anterior plate ϐixation of sacral fractures [published online ahead of print, 2020 May 1]. Injury, 2020; S0020-1383(20)30276-X; doi:10.1016/j.injury.2020.03.049. 42. Zheng SN, Yao QQ, Mao FY, et al. Application of 3D printing rapid prototyping-assisted percutaneous ϐixation in the treatment of intertrochanteric fracture. Exp Ther Med, 2017; 14:3644–3650. 43. Wen X, Huang H, Wang C, et al. Comparative biomechanical testing of customized three-dimensional printing acetabular-wing plates for complex acetabular fractures. Adv Clin Exp Med, 2020; 29(4):459–468; doi:10.17219/acem/116749. 44. Weidert S, Andress S, Linhart C, et al. 3D printing method for nextday acetabular fracture surgery using a surface ϐiltering pipeline: feasibility and 1-year clinical results. Int J Comput Assist Radiol Surg, 2020; 15(3):565–575; doi:10.1007/s11548-019-02110-0. 45. Park JH, Lee Y, Shon OJ, Shon HC, Kim JW. Surgical tips of intramedullary nailing in severely bowed femurs in atypical femur fractures: simulation with 3D printed model. Injury, 2016; 47(6):1318–1324. 46. Otsuki B, Takemoto M, Kawanabe K. Developing a novel custom cutting guide for curved peri-acetabular osteotomy. Int Orthop, 2013; 37(6):1033–1038. 47. Zhou Y, Kang X, Li C, et al. Application of a 3-dimensional printed navigation template in Bernese periacetabular osteotomies: a cadaveric study. Medicine (Baltimore), 2016; 95:e5557. 48. Fukushima K, Takahira N, Uchiyama K, Moriya M, Takaso M. Preoperative simulation of periacetabular osteotomy via a threedimensional model constructed from salt. SICOT J, 2017; 3:14. 49. Wang W, Hu W, Yang P, Dang XQ, Li XH, Wang KZ. Patient-speciϐic core decompression surgery for early-stage ischemic necrosis of the femoral head. PLoS One, 2017; 12:e0175366. 50. Li B, Lei P, Liu H, et al. Clinical value of 3D printing guide plate in core decompression plus porous bioceramics rod placement for the treatment of early osteonecrosis of the femoral head. J Orthop Surg Res, 2018; 13:130. 51. Zhang Y, Zhang L, Sun R, et al. A new 3D-printed titanium metal trabecular bone reconstruction system for early osteonecrosis of the femoral head. Medicine (Baltimore), 2018; 97:e11088. 52. Verma T, Mishra A, Agarwal G, Maini L. Application of three dimensional printing in surgery for cam type of femoro-acetabular impingement. J Clin Orthop Trauma, 2018; 9:241–246.

References

53. Wong TT, Lynch TS, Popkin CA, Kazam JK. Preoperative use of a 3Dprinted model for Femoroacetabular impingement surgery and its effect on planned Osteoplasty. AJR Am J Roentgenol, 2018; 211:W116– W121. 54. Bockhorn L, Gardner SS, Dong D, Karmonik C, Elias S, Gwathmey FW, Harris JD. Application of three-dimensional printing for pre-operative planning in hip preservation surgery. J Hip Preserv Surg, 2019; 6(2):164–169. 55. Wang S, Wang L, Liu Y, et al. 3D printing technology used in severe hip deformity. Exp Ther Med, 2017; 14:2595–2599. 56. Xu J, Li D, Ma RF, Barden B, Ding Y. Application of rapid prototyping pelvic model for patients with DDH to facilitate arthroplasty planning: a pilot study. J Arthroplasty, 2015; 30:1963–1970. 57. Zhang YZ, Lu S, Yang Y, Xu YQ, Li YB, Pei GX. Design and primary application of computer-assisted, patient-speciϐic navigational templates in metal-on-metal hip resurfacing arthroplasty. J Arthroplasty, 2011; 26(7):1083–1087; doi:10.1016/j.arth.2010.08.004. 58. Won SH, Lee YK, Ha YC, Suh YS, Koo KH. Improving pre-operative planning for complex total hip replacement with a rapid prototype model enabling surgical simulation. Bone Joint J, 2013; 95:1458–1463. 59. Zerr J, Chatzinoff Y, Chopra R, Estrera K, Chhabra A. Three-dimensional printing for preoperative planning of total hip arthroplasty revision: case report. Skeletal Radiol, 2016; 45:1431–1435. 60. Hughes AJ, DeBuitleir C, Soden P, et al. 3D printing aids acetabular reconstruction in complex revision hip arthroplasty. Adv Orthop, 2017; 2017:1–7. 10.1155/2017/8925050. 61. Bagaria V, Chaudhary K. A paradigm shift in surgical planning and simulation using 3Dgraphy: experience of ϐirst 50 surgeries done using 3D-printed biomodels. Injury, 2017; 48:2501–2508. 62. Li H, Qu X, Mao Y, Dai K, Zhu Z. Custom acetabular cages offer stable ϐixation and improved hip scores for revision THA with severe bone defects. Clin Orthop Relat Res, 2016; 474:731–740. 63. Mao Y, Xu C, Xu J, et al. The use of customized cages in revision total hip arthroplasty for Paprosky type III acetabular bone defects. Int Orthop, 2015; 39:2023–2030. 64. Chen X, Xu L, Wang Y, Hao Y, Wang L. Image-guided installation of 3Dprinted patient-speciϐic implant and its application in pelvic tumor resection and reconstruction surgery. Comput Methods Programs Biomed, 2016; 125:66–78.

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65. Barlow BT, Oi KK, Lee YY, Carli AV, Choi DS, Bostrom MP. Outcomes of custom ϐlange acetabular components in revision total hip arthroplasty and predictors of failure. J Arthroplasty, 2016; 31:1057–1064. 66. Moore KD, McClenny MD, Wills BW. Custom triϐlange acetabular components for large acetabular defects: minimum 10-year follow-up. Orthopedics, 2018; 41:e316–e320. 67. Myncke I, van Schaik D, Scheerlinck T. Custom-made triϐlanged acetabular components in the treatment of major acetabular defects. Short-term results and clinical experience. Acta Orthop Belg, 2017; 83:341–350. 68. Colen S, Harake R, De Haan J, Mulier M. A modiϐied custom-made triϐlanged acetabular reconstruction ring (MCTARR) for revision hip arthroplasty with severe acetabular defects. Acta Orthop Belg, 2013; 79:71–75. 69. DeBoer DK, Christie MJ, Brinson MF, Morrison JC. Revision total hip arthroplasty for pelvic discontinuity. J Bone Joint Surg Am, 2007; 89:835–840. 70. Wind MA, Jr, Swank ML, Sorger JI. Short-term results of a custom triϐlange acetabular component for massive acetabular bone loss in revision THA. Orthopedics, 2013; 36:e260–e265. 71. Taunton MJ, Fehring TK, Edwards P, Bernasek T, Holt GE, Christie MJ. Pelvic discontinuity treated with custom triϐlange component: a reliable option. Clin Orthop Relat Res, 2012; 470:428–434. 72. De Martino I, Strigelli V, Cacciola G, Gu A, Bostrom MP, Sculco PK. Survivorship and clinical outcomes of custom triϐlange acetabular components in revision total hip arthroplasty: a systematic review. J Arthroplasty, 2019; 34:2511–2518. 73. Henckel J, Holme TJ, Radford W, Skinner JA, Hart AJ. 3D-printed patient-speciϐic guides for hip arthroplasty. J Am Acad Orthop Surg, 2018; 26:e342–e348. 74. Small T, Krebs V, Molloy R, Bryan J, Klika AK, Barsoum WK. Comparison of acetabular shell position using patient speciϐic instruments vs. standard surgical instruments: a randomized clinical trial. J Arthroplasty, 2014; 29:1030–1037. 75. Sallent A, Vicente M, Reverté MM, et al. How 3D patient-speciϐic instruments improve accuracy of pelvic bone tumour resection in a cadaveric study. Bone Joint Res, 2017; 6:577–583. 76. Blakeney WG, Day R, Cusick L, Smith RL. Custom osteotomy guides for resection of a pelvic chondrosarcoma. Acta Orthop, 2014; 85:438–441.

References

77. Wong KC, Kumta SM, Geel NV, Demol J. One-step reconstruction with a 3D-printed, biomechanically evaluated custom implant after complex pelvic tumor resection. Comput Aided Surg, 2015; 20:14–23. 78. Holzapfel BM, Pilge H, Prodinger PM, et al. Customised osteotomy guides and endoprosthetic reconstruction for periacetabular tumours. Int Orthop, 2014; 38:1435–1442. 79. Liang H, Ji T, Zhang Y, Wang Y, Guo W. Reconstruction with 3D-printed pelvic endoprostheses after resection of a pelvic tumour. Bone Joint J, 2017; 99:267–275. 80. Wang B, Hao Y, Pu F, Jiang W, Shao Z. Computer-aided designed, three dimensional-printed hemipelvic prosthesis for peri-acetabular malignant bone tumour. Int Orthop, 2018; 42:687–694. 81. Wan J, Zhang C, Liu YP, He HB. Surgical treatment for shepherd’s crook deformity in ϐibrous dysplasia: there is no best, only better. Int Orthop, 2019; 43:719–726. 82. Cherkasskiy L, Caffrey JP, Szewczyk AF, et al. Patient-speciϐic 3D models aid planning for triplane proximal femoral osteotomy in slipped capital femoral epiphysis. J Child Orthop, 2017; 11:147–153. 83. Zheng P, Yao Q, Xu P, Wang L. Application of computer-aided design and 3D-printed navigation template in locking compression pediatric hip Plate™ placement for pediatric hip disease. Int J Comput Assist Radiol Surg, 2017; 12:865–871. 84. Zheng P, Xu P, Yao Q, Tang K, Lou Y. 3D-printed navigation template in proximal femoral osteotomy for older children with developmental dysplasia of the hip. Sci Rep, 2017; 7:44993. 85. Xia RZ, Zhai ZJ, Chang YY, Li HW. Clinical applications of 3-dimensional printing technology in hip joint. Orthop Surg, 2019; 11(4):533–544; doi:10.1111/os.12468. 86. Woo SH, Sung MJ, Park KS, Yoon TR. Three-dimensional-printing technology in hip and pelvic surgery: current landscape. Hip Pelvis, 2020; 32(1):1–10; doi:10.5371/hp.2020.32.1.1. 87. Chae MP, Lin F, Spychal RT, Hunter-Smith DJ, Rozen WM. 3D-printed haptic “reverse” models for preoperative planning in soft tissue reconstruction: a case report. Microsurgery, 2015; 35(2):148–153. 88. Garcia-Tutor E, Romeo M, Chae MP, Hunter-Smith DJ, Rozen WM. 3D volumetric modeling and microvascular reconstruction of irradiated lumbosacral defects after oncologic resection. Front Surg, 2016; 3:66. 89. Jessop ZM, Al-Sabah A, Gardiner MD, Combellack E, Hawkins K, Whitaker IS. 3D bioprinting for reconstructive surgery: principles,

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applications and challenges. J Plast Reconstr Aesthet Surg, 2017; 70(9):1155–1170. 90. Tarassoli SP, Jessop ZM, Al-Sabah A, Gao N, Whitaker S, Doak S, Whitaker IS. Skin tissue engineering using 3D bioprinting: an evolving research ϐield. J Plast Reconstr Aesthet Surg, 2018; 71(5):615–623. 91. Varkey M, Visscher DO, van Zuijlen PP, Atala A, Yoo JJ. Skin bioprinting: the future of burn wound reconstruction?. Burns Trauma, 2019; 7(1):4. 92. K ogelenberg SV, Yue Z, Dinoro JN, Baker CS, Wallace GG. Threedimensional printing and cell therapy for wound repair. Adv Wound Care, 2018; 7(5):145–156. 93. Saharan L, Sharma A, de Andrade MJ, Baughman RH, Tadesse Y. Design of a 3D printed lightweight orthotic device based on twisted and coiled polymer muscle: iGrab hand orthosis. In Active and Passive Smart Structures and Integrated Systems. vol. 10164. 2017; 1016428. 94. Paterson AM, Donnison E, Bibb RJ, Ian Campbell R. Computer-aided design to support fabrication of wrist splints using 3D printing: a feasibility study. Hand Ther, 2014; 19(4):102–113. 95. Herbert N, Simpson D, Spence WD, Ion W. A preliminary investigation into the development of 3-D printing of prosthetic sockets. J Rehabil Res Dev, 2005; 42(2):141. 96. Rogers B, Bosker GW, Crawford RH, et al. Advanced trans-tibial socket fabrication using selective laser sintering. Prosthet Orthot Int, 2007; 31(1):88–100. 97. Hsu LH, Huang GF, Lu CT, Hong DY, Liu SH. The development of a rapid prototyping prosthetic socket coated with a resin layer for transtibial amputees. Prosthet Orthot Int, 2010; 34(1):37–45. 98. Laurentis KJ, Mavroidis C. Mechanical design of a shape memory alloy actuated prosthetic hand. Technol Health Care, 2002; 10(2):91–106. 99. Xu G, Gao L, Tao K, et al. Three-dimensional-printed upper limb prosthesis for a child with traumatic amputation of right wrist. Medicine, 2017; 96(52):e9426. 100. Hammock ML, Chortos A, Tee BC, Tok JB, Bao Z. 25th anniversary article: The evolution of electronic skin (e-skin): a brief history, design considerations, and recent progress. Adv Mater, 2013; 25:5997 101. Zou Y, Han Q, Weng X, et al. The precision and reliability evaluation of 3- dimensional printed damaged bone and prosthesis models by stereolithography appearance. Medicine, 2018; 97(6):e9797.

Chapter 7

Stem Cell Therapy in Orthopaedics

Ben Daviesa and Wasim Khana,b aUniversity

of Cambridge, UK Hospital, Cambridge, UK [email protected], [email protected]

bAddenbrooke’s

Total hip arthroplasty is one of the most successful orthopaedic operations performed, and the longevity of the implants depends on accurate component placement. Accurate component alignment is associated with reduced mechanical wear, dislocation and revision surgery. Traditionally, accurate component alignment relies on the surgeon using jigs and referencing these from anatomical landmarks. However, this leads to a wide variability in component position. Computer navigation systems aim to optimise component placement and longevity. This chapter will describe the different types of computer navigation systems available and their use in total hip arthroplasty and hip resurfacing. This chapter will also highlight the limitations to navigation which have prevented a more widespread uptake.

The Hip Joint Edited by K. Mohan Iyer

Copyright © 2022 Jenny Stanford Publishing Pte. Ltd.

ISBN 978-981-4877-51-0 (Hardcover), 978-1-003-16546-0 (eBook)

www.jennystanford.com

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7.1

Introduction

Hip arthritis is a major cause of disability worldwide. Over the past 30 years, total hip replacement surgery has demonstrated signiϐicant clinical and commercial success. In the United States more almost 500,000 total hip replacements were predicted to be performed in 2020 [1], a ϐigure set to rise as the population ages. Most implants have shown good long-term results with a high level of patient satisfaction. The results are improving due to better implant designs, materials and manufacturing, and better patient education. The key to the success of a total hip replacement is accurate alignment and stability of the components; a poorly aligned acetabular cup increases the risk of dislocation, reduces the range of motion and can also accelerate component wear, leading to early prosthesis failure. It can also result in impingement, osteolysis and leg length discrepancy. It is difϐicult to accurately predict acetabular and femoral component alignment in a number of patients and in complex and revision cases. The measurement of acetabular component position from plain radiographs can also be inaccurate [2]. Orthopaedic procedures dealing with a nondeformable tissue such as bone are suitable for computerised guidance based on pre-operatively and intra-operatively obtained images. Computerassisted surgery can take a number of forms ranging from active and semi-active robotic systems, which rely at least in part on the robot performing part of the procedure, to the more passive navigation systems which do not perform any part of the procedure. Navigation systems work by providing information and guiding surgeons using conventional tools to perform the surgery, and we have previously described the role of navigation in hip arthroplasty [3], knee arthroplasty [4] as well as osteotomies [5]. Navigation in total hip arthroplasty has been developed to allow proper placement of the acetabular component, measurement of limb length changes, better recreation of the hip offset, enablement of minimally invasive surgery (MIS) and proper placement of components for hip-resurfacing procedures [6, 7]. Hip arthroplasty is suited to computer navigation as speciϐic targets for component positioning have been deϐined. The orientation of the acetabular component is probably the most important factor

Limitations of Conventional Alignment Jigs

in successful hip arthroplasty, and not surprisingly, computernavigated acetabular positioning has received the most attention in the literature. Lewinnek et al. [8] deϐined a ‘safe zone’ for acetabular cup positioning of 5°–25° of anteversion and 30°–50° of inclination. Components positioned outside this range were approximately four times more likely to dislocate. Although the study by Lewinnek et al. was based on only nine dislocations, Biedermann et al. [9] showed similar results in their series of 127 dislocations. Although there remains some controversy regarding the use of the Lewinnek ‘safe zone’, these values are still used by the majority of hip surgeons [10].

7.2 Limitations of Conventional Alignment Jigs Most surgeons use intra-operative alignment jigs to place the acetabular component referencing of the position of the patient on the operating table. In the lateral position, vertical orientation of the cup is usually judged from the ϐloor, and anteversion from the patient’s superior shoulder. However, it is now known that the exact position of the patient’s pelvis on the table is difϐicult to judge with drapes, particularly in obese patients. Additional technical challenges include dysplasia and altered patient anatomy, absence of usual landmarks as commonly encountered in revision cases, poor surgical exposure and obscured view with haemorrhage. The surgeon should not assume that the orientation of the pelvis is in line with the table or the patient’s body. In the lateral position the lumbar lordotic curve ϐlattens and the pelvis may be ϐlexed forward as much as 35° [11]. In addition, the superior aspect of the acetabulum may be tilted towards the foot of the table by 10°–15°. This means that cups placed with alignment jigs may actually be excessively retroverted and too vertical. Digioia et al. [12] further demonstrated the high variability of mechanical acetabular alignment guides in the lateral position. They found signiϐicant variability in pelvic orientation, resulting in unacceptable alignment in 78% of acetabular components which had been placed with mechanical alignment guides. The conventional instruments are largely similar between manufacturers and have not changed signiϐicantly over the past 30 years. Using conventional instruments to guide implant placement can result in malposition, even with experienced hands.

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7.3 Types of Computer Navigation Systems Following advances in 3D sensor technology, it became possible to develop computer navigation systems. These systems have been in use in hip arthroplasty since the 1990s [13, 14]. Navigation systems use optical or magnetic sensors to determine and track the 3D position of bones, surgical instruments and implants. The pre-operative or intra-operative data obtained allow the system to build a 3D model of the pelvis to guide component placement. The imaging systems which are used during computer-assisted navigation surgery can be divided into image-based and imageless systems. Image-based systems require the collection of morphological information by preoperative computerised tomography (CT) or magnetic resonance imaging (MRI) scans or by means of intra-operative ϐluoroscopy. Imageless systems use a virtual anatomical model which is embedded in the software and is supplemented by intra-operative registration data of anatomical landmarks. The most common means of doing this is using infrared light-emitting diodes or reϐlective markers on surgical instruments and at anatomical bony landmarks, including the anterior superior iliac spine and pubic tubercle. Infrared cameras that are coupled with an emitter and the navigation computer track the movement of the markers; however, an uninterrupted line of sight must be maintained. The line of sight does not appear to be a problem with magnetic sensors, although they are less commonly used as electromechanical devices in the operation theatre may interfere with their accuracy. Imageless systems appear to the most popular systems in clinical use, judging by our experience and the published literature on navigation. The accuracy, however, depends on the ability to identify bony landmarks, and this may be limited by soft-tissue thickness. Image-guided systems are more accurate but involve pre-operative planning, associated costs and radiation.

7.4 Computer Navigation in Total Hip

Arthroplasty

Total hip replacements are being performed in younger and more active patients, and there is a need to improve the accuracy of surgical techniques to optimise the survival and function of implants.

Computer Navigation in Total Hip Arthroplasty

Computer-assisted or computer-navigated surgery provides the means to allow this more accurate placement of implants. There are a number of navigated systems available. An increasing number of commercial navigation options are now available, usually designed by implant manufacturers to be used solely with their systems. These systems develop a 3D model of the patient’s pelvis and map the position of the surgeon’s instruments in relation to this model, which is used to guide component positioning. Computer navigation of the acetabular component ϐirst requires registration of anatomical landmarks so that the computer can determine where the pelvis lies in space. This is usually done by registering the anterior superior iliac spine and the pubic tubercle. By referencing these landmarks the anterior pelvic plane is created, which is used for referencing the cup position. For imageless systems, registration is accomplished with optical trackers mounted on to the pelvis. An optical pointer is then used to register the anterior superior iliac spine and the pubic tubercle either through small incisions or simply by palpation and then registration of the soft tissue directly over the anatomical landmark. For imageless systems the registration part of the process is usually done while the patient is supine in order to access the opposite anterior superior iliac spine. The patient can then be turned to the lateral decubitus position, though this can be a problem when there is an optical tracker mounted on to the pelvis. The transverse acetabular ligament has also been used as a reference point to assist in determining the true version plane of the acetabulum. The transverse acetabular ligament is that part of the acetabular labrum which bridges the acetabular notch and is often used as a reference point for cup version by surgeons using a freehand technique. When the transverse acetabular ligament is registered along with the superior aspect of the acetabulum, the result is the creation of a true acetabular inlet plane. Kelley and Swank [15] found that by using this method 82% of the acetabular components were placed within the abduction safe zone and 71% were placed within the anteversion safe zone, as deϐined by Lewinnek. Suksathien et al. [16] compared the acetabular component positioning and the operative time in two consecutive groups of short-stem cementless total hip replacement performed with and without navigation. According to the criteria of Lewinnek, 100% of the navigated hips

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were in the safe zone for both abduction and anteversion compared to 48.4% of the non-navigated hips. The mean operative time was 110.67 and 107.09 minutes for the navigated and non-navigated groups, respectively, and this difference was not signiϐicant. There are studies, however, which did not ϐind any difference in inclination and anteversion between navigation and traditional total hip replacements [17]. Leg length discrepancy following total hip replacement can contribute to poor hip function. Abnormal gait, pain, neurological dysfunction and patient dissatisfaction have all been described as a result of leg length inequality. Manzotti et al. [18] showed that signiϐicantly better leg lengths could be achieved using a computernavigated system compared to freehand techniques. However, this study failed to show any signiϐicant difference in functional outcomes between the two groups. Ogawa et al. [19] retrospectively compared leg length discrepancy in 30 navigated total hip replacements with 40 conventional total hip replacements using a simple manual measurement device. The post-operative discrepancy was not signiϐicantly different between the two groups; it was 3.0 mm (range: 0 to 8 mm) in the navigated group and 2.9 mm (range: 0 to 10 mm) in the conventional group. Xu et al. [20] conducted a meta-analysis of randomised controlled trials (RCTs) looking at computer navigation in total hip replacements and reviewed 13 studies which met their inclusion criteria. They found statistically signiϐicant differences between navigated and conventional total hip replacements in the number of acetabular cups implanted beyond the safe zone, operative time and leg length discrepancy. No signiϐicant differences in cup inclination, anteversion, incidences of post-operative dislocation or deep vein thrombosis were found. They concluded that the use of computer navigation improves the precision of acetabular cup placement by decreasing outliers and leg length discrepancy. More recent meta-analyses have been more equivocal. Snijder et al. showed better anteversion and inclination using navigation [21]. Jia et al., however, showed that navigation provides for better inclination but is outperformed by conventional placement in terms of anteversion [22], although their review only looked at the Orthopilot® system. MIS would appear to be the ideal technique to utilise the accuracy of computerised navigation. The smaller operative ϐield naturally

Computer Navigation in Total Hip Resurfacing

makes component positioning more difϐicult by freehand techniques. An RCT conducted by Renkawitz et al. [23] showed the use of imageless navigation in MIS to allow for more accurate component placement compared to freehand MIS. However, operative time was increased by 17%, and there was no difference in patient-reported outcome measures at 1 year.

7.5 Computer Navigation in Total Hip Resurfacing Hip resurfacing has been used as a bone-conserving alternative to total hip arthroplasty in young and active adults with degenerative hip disease. The larger head diameters offer greater post-operative stability and may decrease wear rates. However, hip resurfacing is inherently more difϐicult to perform than traditional total hip arthroplasty because of the limited femoral resection which makes acetabular visualisation more difϐicult. Preparing the acetabulum prior to addressing the femoral head creates limitations in terms of exposure and mobilisation of tissues, thus posing a technical challenge to the surgeon and increasing the risk of component malalignment. The orientation of the acetabular component is probably the most important factor in successful hip resurfacing. It has been shown that increasing the inclination of the acetabular component above 55° in hip resurfacing leads to an ‘edge loading’ effect with a much greater release of metal ions [24, 25]. Elevated serum metal ions have been associated with local pseudotumour formation [26] and have unknown systemic effects which may include carcinogenic potential [27, 28]. These issues have led to a signiϐicant decline in resurfacing procedures from almost 10% of all hip arthroplasties in 2004 to 0.6% in 2018 in England, Wales, Northern Ireland and the Isle of Man [29]. Errors in component positioning during the surgeon’s learning curve are common in hip resurfacing. Navigation of the acetabular cup in hip resurfacing follows an identical procedure to total hip arthroplasty. Imageless navigation in hip resurfacing has been shown to help avoid component malposition during the surgeon’s learning curve [30–32]. There is a risk of femoral neck fracture

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associated with hip resurfacing, with a prevalence reported from 0% to 17% [33, 34]. Among other factors, several studies have suggested that notching of the superolateral aspect of the femoral neck and varus placement of the femoral component increase the likelihood of femoral neck fracture [35, 36]. Preparation of the femoral side is therefore an attractive target for computer guidance. The key step for navigated preparation of the femoral side is the guide wire insertion into the femoral head to determine implant orientation. Online display of the actual wire position in three dimensions allows for immediate correction and best match with the preplanned pin alignment. The wire is then overdrilled and replaced by the instrumentation guide for femoral head preparation. Navigation has been shown to improve the femoral implant position [37, 38]. A meta-analysis based on 7 studies, 520 patients and 555 hip-resurfacing arthroplasties concluded that computer navigation systems make the femoral component positioning in hip-resurfacing arthroplasty easier and more precise [39].

7.6 Limitations of Computer Navigation Systems There is an increasing body of evidence, including RCTs, metaanalyses and systematic reviews, which has been published on navigated hip arthroplasty. The most consistent ϐinding from these studies is that computer navigation improves the accuracy of acetabular cup positioning and minimises outliers in both total hip arthroplasty and hip resurfacing. The accuracy of femoral component placement in hip resurfacing can also be improved with navigation and errors during the surgeon’s learning curve minimised. An increasing number of commercial navigation options are now available, usually designed by implant manufacturers to be used solely with their systems. Computer navigation is not a new concept or technology and has been around since the 1990s. Despite greater availability, the use of these systems is limited, and uptake has been slow as they are perceived to be cumbersome, time-consuming and costly. There is a general reluctance of the surgical community to accept navigation as a routine part of the arthroplasty process. Experienced surgeons

Conclusion

can be reluctant to change tried and tested methods. However, there is substantial evidence that computerised systems can improve component positioning compared to freehand techniques. If we assume that optimal component positioning leads to better outcomes, it is logical to predict a resurgence in interest in computernavigated hip arthroplasty. The results of long-term clinical outcome studies comparing navigated against non-navigated hips are not yet available. Computer navigation has the ability to improve the quality of prosthetic joint arthroplasty similar to the use of intra-operative ϐluoroscopy in fracture surgery. There are, however, various obstacles to performing computer-assisted surgery. Additional equipment is needed in the operating theatre, which may have to be modiϐied. A technician may also be needed speciϐically for the navigation equipment. The additional navigation steps throughout the procedure add time to the case, which can be important from an anaesthetic point of view and also in terms of getting through the operating list. The surgical approach has to be considered carefully as imageless techniques which require registration with the patient supine. The patient may then need to be re-positioned into the lateral decubitus position. Personnel in the operating theatre need to think carefully about moving so as not to interrupt the line of sight of the sensors for imageless techniques. All systems increase the operative time. Both the additional equipment and the increase in operating time contribute to the extra immediate and ongoing cost of computer-navigated surgery. Some studies have reported difϐiculty in accurately registering the pelvis using imageless navigation systems [40]. These factors are limiting a more widespread uptake of navigation.

7.7

Conclusion

Although there is proven improvement in the accuracy of component alignment with navigation, this has not yet conclusively shown to translate to better functional results and improved survival of the implants. Long-term studies with large numbers will be needed to demonstrate this before navigation and its limitations become more readily accepted.

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References 1. Singh JA, Yu S, Chen L, Cleveland JD. Rates of total joint replacement in the united states: future projections to 2020–2040 using the national inpatient sample. J Rheumatol, 2019; 46:1134–1140. 2. Kalteis T, et al. Position of the acetabular cup—accuracy of radiographic calculation compared to CT-based measurement. Eur J Radiol, 2006; 58:294–300. 3. Punwar S, Khan WS, Longo UG. The use of computer navigation in hip arthroplasty: literature review and evidence today. Ortop Traumatol Rehabil, 2011; 13:431–438. 4. Wong JM-L, Khan WS, Saksena J. The role of navigation in total knee replacement surgery. J Perioper Pract, 2013; 23:202–207. 5. Picardo NE, Khan W, Johnstone D. Computer-assisted navigation in high tibial osteotomy: a systematic review of the literature. Open Orthop J, 2012; 6:305–312. 6. Dheerendra S, Khan W, Saeed MZ, Goddard N. Recent developments in total hip replacements: cementation, articulation, minimal-invasion and navigation. J Perioper Pract, 2010; 20:133–138. 7. Deep K, Shankar S, Mahendra A. Computer assisted navigation in total knee and hip arthroplasty. SICOT J, 2017; 3:50. 8. Lewinnek GE, Lewis JL, Tarr R, Compere CL, Zimmerman JR. Dislocations after total hip-replacement arthroplasties. J Bone Joint Surg Am, 1978; 60:217–220. 9. Biedermann R, et al. Reducing the risk of dislocation after total hip arthroplasty: the effect of orientation of the acetabular component. J Bone Joint Surg Br, 2005; 87B:762–769. 10. Abdel MP, Roth P von, Jennings MT, Hanssen AD, Pagnano MW. What safe zone? The vast majority of dislocated THAs are within the Lewinnek safe zone for acetabular component position. Clin Orthop Relat Res, 2016; 474:386–391. 11. McCollum DE, Gray WJ. Dislocation after total hip arthroplasty causes and prevention. Clin Orthop Relat Res, 1990; 261:159–170. 12. DiGioia AM, et al. Comparison of a mechanical acetabular alignment guide with computer placement of the socket. J Arthroplasty, 2002; 17:359–364. 13. Bargar WL. Robots in orthopaedic surgery: past, present, and future. Clin Orthop Relat Res, 2007; 463:31–36.

References

14. Hepinstall MS. Robotic total hip arthroplasty. Orthop Clin North Am, 2014; 45:443–456. 15. Kelley TC, Swank ML. Role of navigation in total hip arthroplasty. J Bone Joint Surg Am, 2009; 91(Suppl 1):153–158. 16. Suksathien Y, Suksathien R, Chaiwirattana P. Acetabular cup placement in navigated and non-navigated total hip arthroplasty (THA): results of two consecutive series using a cementless short stem. J Med Assoc Thai, 2014; 97:629–634. 17. Pagkalos J, Chaudary MI, Davis ET. Navigating the reaming of the acetabular cavity in total hip arthroplasty: does it improve implantation accuracy? J Arthroplasty, 2014; 29:1749–1752. 18. Manzotti A, Cerveri P, Momi ED, Pullen C, Confalonieri N. Does computer-assisted surgery beneϐit leg length restoration in total hip replacement? Navigation versus conventional freehand. Int Orthop, 2009; 35:19–24. 19. Ogawa K, Kabata T, Maeda T, Kajino Y, Tsuchiya H. Accurate leg length measurement in total hip arthroplasty: a comparison of computer navigation and a simple manual measurement device. Clin Orthop Surg, 2014; 6:153–158. 20. Xu K, et al. Computer navigation in total hip arthroplasty: a metaanalysis of randomized controlled trials. Int J Surg, 2014; 12:528–533. 21. Snijders T, Gaalen SM, Gast A. Precision and accuracy of imageless navigation versus freehand implantation of total hip arthroplasty: a systematic review and meta-analysis. Int J Med Robot, 2017; 13:e1843. 22. Jia J, et al. Clinical efϐicacy of orthopilot navigation system versus conventional manual of total hip arthroplasty: a systematic review and meta-analysis. Medicine, 2019; 98:e15471. 23. Renkawitz T, et al. Impingement-free range of movement, acetabular component cover and early clinical results comparing ‘femur-ϐirst’ navigation and ‘conventional’ minimally invasive total hip arthroplasty. Bone Joint J, 2015; 97B:890–898. 24. Haan RD, Campbell PA, Su EP, Smet KAD. Revision of metal-on-metal resurfacing arthroplasty of the hip: the inϐluence of malpositioning of the components. J Bone Joint Surg Br, 2008; 90:1158–1163. 25. Langton DJ, Jameson SS, Joyce TJ, Webb J, Nargol AVF. The effect of component size and orientation on the concentrations of metal ions after resurfacing arthroplasty of the hip. J Bone Joint Surg Br, 2008; 90:1143–1151.

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26. Grammatopoulos G, et al. Optimal acetabular orientation for hip resurfacing. J Bone Joint Surg Br, 2010; 92:1072–1078. 27. Keegan GM, Learmonth ID, Case CP. Orthopaedic metals and their potential toxicity in the arthroplasty patient. Bone Joint J, 2007; 89B:567–573. 28. Hartmann A, et al. Metal ion concentrations in body ϐluids after implantation of hip replacements with metal-on-metal bearing– systematic review of clinical and epidemiological studies. PLoS One, 2013; 8:e70359. 29. National Joint Registry for England, Wales. Northern Ireland & the Isle of Man. NJR 16th Annual Report 2019.pdf. 2019. 30. Romanowski JR, Swank ML. Imageless navigation in hip resurfacing: avoiding component malposition during the surgeon learning curve. J Bone Joint Surg Am, 2008; 90:65–70. 31. Seyler TM, Lai LP, Sprinkle DI, Ward WG, Jinnah RH. Does computerassisted surgery improve accuracy and decrease the learning curve in hip resurfacing? A radiographic analysis. J Bone Joint Surg Am, 2008; 90(Suppl 3):71–80. 32. Cobb JP, Kannan V, Brust K, Thevendran G. Navigation reduces the learning curve in resurfacing total hip arthroplasty. Clin Orthop Relat Res, 2007; 463:90–97. 33. Amstutz HC, Campbell PA, Duff MJL. Fracture of the neck of the femur after surface arthroplasty of the hip. J Bone Joint Surg Am, 2004; 86:1874–1877. 34. Shimmin AJ, Bare J, Back DL. Complications associated with hip resurfacing arthroplasty. Orthop Clin North Am, 2005; 36:187–193. 35. Marker DR, et al. Femoral neck fractures after metal-on-metal total hip resurfacing. J Arthroplasty, 2007; 22:66–71. 36. Morison Z, Olsen M, Higgins GA, Zdero R, Schemitsch EH. The biomechanical effect of notch size, notch location, and femur orientation on hip resurfacing failure. IEEE Trans Biomed Eng, 2013; 60:2214–2221. 37. Kitada M, et al. Validation of the femoral component placement during hip resurfacing: a comparison between the conventional jig, patientspeciϐic template, and CT-based navigation: validation of the femoral component placement during hip resurfacing. Int J Med Robot, 2013; 9:223–229.

References

38. Hachmi ME, Penasse M. Our midterm results of the birmingham hip resurfacing with and without navigation. J Arthroplasty, 2014; 29:808– 812. 39. Liu H, Li L, Gao W, Wang M, Ni C. Computer navigation vs conventional mechanical jig technique in hip resurfacing arthroplasty. J Arthroplasty, 2013; 28:98–102.e1. 40. Lin F, et al. Limitations of imageless computer-assisted navigation for total hip arthroplasty. J Arthroplasty, 2011; 26:596–605.

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Chapter 8

Principles of Anterior Approach for Total Hip Arthroplasty

Alessandro Geraci,a Paolo Segnanaa and Alberto Ricciardib aOrthopaedic bOrthopaedic

Department, Ca’ Foncello Hospital, Treviso, Italy Department, San Giovanni e Paolo Hospital,

Venice, Italy [email protected], [email protected], [email protected]

8.1

Introduction

Hip prosthetic surgery today offers solutions aimed at saving the bone patrimomy and respecting muscles and tendons in order to reduce complications and reduce recovery times. The goal of hip replacement surgery is to eliminate the pain often caused by a degenerative disease such as arthrosis, restore good range of motion and allow the patient to carry out his/her daily activities in the gradual functional recovery.

The Hip Joint Edited by K. Mohan Iyer

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The anterior approach route, in association with dedicated instruments, allows hip replacement with a minimally invasive approach, opening and not removing the muscle ϐibers. The ϐirst description of the anterior hip approach was described in 1881 by the German surgeon Carl Hueter, assistant to Langenbeck [1]. In 1917, Marius N. Smith-Petersen spread in the Anglo-Saxon world, with an article in the JBJS, the use of this approach, which today is known precisely as Smith-Petersen access [2]. SmithPetersen and Judet used this surgical access for hip replacement treatment [3], while Charley popularised the trans-trochanteric approach. In the 1980s, Judet tried to improve this surgical access for hip replacement by developing a particular traction bed which facilitated the manoeuvres of moving the lower limb during surgical practice [4]. Recently Matta [5], Laude [6] and Moreau [7] tried to perfect the surgical procedure by making the surgical act reproducible using dedicated instruments, which make the surgical act less difϐicult and invasive.

8.2

Surgical Technique

The anterior approach to the hip uses two internal nervous planes: superϐicial and deep. The more superϐicial plan does located between the sartorius muscle (innervated by the femoral nerve), placed medially, and the tensor muscle of the fascia lata (pertaining to the gluteus superior nerve), placed laterally. The deep plane passes between the rectus femoris (femoral nerve) and the tensor of the fascia lata and the gluteus medius (superior gluteus nerve).

8.2.1

Choice of Patients

The anterior approach to the hip is a way that uses the anterior region of the hip to be able to attack the joint. The anterior region is, in fact, poor in adipose tissue and is easily operable. For this reason, all types of patients can be treated, even obese subjects (Fig. 8.1). In fact, in patients with large abdominal fat it is simply necessary to move the excess abdomen with a skin adhesive and the area to be operated will be free from obstacles (Fig. 8.2).

Surgical Technique

Figure 8.1 The obese subject has poorly represented fat in the anterior region of the hip.

Figure 8.2 Obese patient before and after applying skin adhesive to displace abdominal fat.

The real counter-indication to this technique is a major deformity of the patient’s acetabulum or femoral neck, which can make it difϐicult to manoeuvre the limb during surgery.

8.2.2

Patient Positioning

The normal operating table or a dedicated operating table with limb traction can be used (Fig. 8.3). The patient is placed supine on the table surgery, and if you are not using a bed of traction, the apex of the greater trochanter must match at the joint of the operating table to facilitate ϐlexion or extension of the hip.

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Figure 8.3 Example of an operating table with dedicated traction for the anterior approach to the hip.

A variant involves positioning the patient in lateral decubitus: The easy extension of the hip in lateral decubitus facilitates exposure and preparation of the femur, but difϐiculty in ϐixing the pelvis ϐirmly increases the risk of version and inclination errors of the acetabular component; furthermore, the evaluation of heterometry is more difϐicult and the use of the most painstaking image intensiϐier. The operation is performed with an anaesthetic which produces maximum muscle relaxation to avoid traction damage, which mainly affects the tensor fascia lata and the gluteus minimus and can determine post-operative pain and increase the rate of heterotopic ossiϐication.

8.2.3

Skin Incision

The main landmark is the superior anterior iliac spine. The engraving described by Lesur and Laude [8] begins 2 cm distal and 2 cm lateral compared to the anterior superior iliac spine (ASIS) and extends lengthwise for about 7 cm pointing to the ϐibular head (Fig. 8.4).

Surgical Technique

Figure 8.4 Locations of the iliac crest, greater trochanter and the anterior superior iliac spine are marked. The skin incision begins 2 cm distal and 2 cm lateral compared to the anterior superior iliac spine and extends lengthwise for about 7 cm pointing to the fibular head.

In the ‘bikini’ variant described by Leunig [9], the incision is at the level of the inguinal skin fold, the groove highlighted ϐlexing the hip, and extends two-thirds laterally and one-third medial to the upper anterior iliac spine with an oblique course (Fig. 8.5). The deep dissection continues equally either in both Lesur’s and Leunig’s versions.

Figure 8.5

Landmarks for the ‘bikini’ skin incision.

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8.2.4 Superficial Dissection: The Intramuscular

Approach

The interstice between the tensor fascia lata and the sartorius is identiϐied by palpation. With scissors, the fascia covering both muscles (ϐirst aponeurosis) is sectioned, taking care not to damage the lateral femorocutaneous nerve, which runs above the sartorius fascia (Fig. 8.6).

Figure 8.6 The incision is extended straight to the superficial aponeurosis of the tensor fascia lata.

A Beckamann retractor is inserted between the tensor of the fascia lata and the sartorius. The aponeurosis of the rectus femoris (second aponeurosis) is visualised and is incised (Fig. 8.7).

8.2.5 Deep Dissection: The Intramuscular Approach The second aponeurosis is incised, and the rectus femoris apart at the top, the anterior circumϐlex arteriovenous bundle immersed in the adipose tissue is identiϐied. It is isolated, tied and cut (Fig. 8.8).

Surgical Technique

Figure 8.7

The aponeurosis of the rectus femoris already engraved.

Figure 8.8 dŚĞĐŝƌĐƵŵŇĞdžĂƌƚĞƌLJŝƐŝƐŽůĂƚĞĚĂŶĚĐƵƚ͘

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Proximally, the reϐlex tendon of the rectus femoris is isolated and intimately adheres to the anterior joint capsule. The joint capsule and the ileocapsular muscle are identiϐied. The capsule is engraved, collected and moved upwards. The ileocapsular muscle is moved up with an elevator inserted between it and the cup. After incising the capsule, the femoral neck is highlighted and three Hohmann retractors (lateral, medial, anterior) are applied to expose the head and the femoral neck (Fig. 8.9). The limb is extra-rotated by 45°, and an osteotomy is performed, which is generally performed trying to leave about 1 cm of the femoral neck (Fig. 8.10). After removing the head of the femur, the cup appears clearly near and in front of us. It proceeds to its milling, as in other surgical techniques.

Figure 8.9 Three Hohmann retractors are applied (lateral, medial, anterior), and the femoral head and neck are exposed.

Surgical Technique

Figure 8.10

Osteotomy of the femoral head.

8.2.6 Femoral Preparation: The Use of the Traction Table At this stage of the surgery, the dedicated orthopaedic bed can be a valuable aid. Through it, a slight traction is applied and the limb is extra-rotated, by the operator’s hands, until the patella assumes a perpendicular position to the axis of the ϐloor. Then the traction is released, and the bed is lowered and adducted to the contralateral limb in order to allow the lifting and exposure of the femur. At this point, a Hohmann retractor is applied on the medial part and a dedicated one on the back (Cobra or Muller retractor) to help lift the femur. A good anterior exposure of the femoral shaft can be obtained. After that, the entrance to the femoral canal is scraped

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with a Volkmann spoon. The ϐirst dedicated rasp (starter rasp) is introduced by hand making wavy movements (Fig. 8.11). Then the further rasps prepare the femoral canal to accommodate the femoral prosthesis.

Figure 8.11

Preparation and exposure of the femur.

8.2.7 Femoral Preparation: The Use of the Traditional Table A traditional trauma bed can be used with the patient’s hip placed on the joint of the bed and both legs placed in a sterile ϐield. The legs of the table are dropped 30°–60° (obtaining extension at the hip); the non-operative leg is placed on a well-padded sterile Mayo stand. With the limb in the neutral position, a femoral hook is carefully placed around the proximal posterior femur from the

Surgical Technique

lateral direction, distal to the vastus ridge, proximal to the gluteus maximus insertion, over (not through) the vastus lateralis, hugging the bone posteriorly [10]. The operative limb is then adducted and externally rotated, keeping the knee straight to decrease anterior soft-tissue tension. The limb to be operated on is placed under the other leg (Fig. 8.12). At this point, a Hohmann retractor is applied on the medial part and a dedicated one on the back (Cobra or Muller retractor) to help lift the femur. A good anterior exposure of the femoral shaft can be obtained. After that, the entrance to the femoral canal is scraped with a Volkmann spoon. The ϐirst dedicated rasp (starter rasp) is introduced by hand making wavy movements. Then the further rasps prepare the femoral canal to accommodate the femoral prosthesis.

Figure 8.12 The leg to be operated on is placed under the other leg and is rotated and extended.

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8.2.8 Dedicated Surgical Instruments To facilitate mini-approaches, special instrumentation was developed to avoid impingement of the soft tissues and provide an easier and more correct placement of the components [11]. The dedicated instruments are used to improve the surgical exposure of the joint in conditions of limited exposure inϐluenced by the dimensions of the wound. The main difϐiculties in this type of surgery are poor visualisation of the anatomic structures, troublesome preparation and troublesome positioning of prosthetic components [12]. Hohmann retractors with long handles and various angulations have been developed so that the assistant’s hands are distanced from the operative ϐield. The reamers for the preparation of the acetabulum have also been modiϐied with an angled arm. In an offset reamer an angled handle is provided to avoid impingement of the soft tissues and avoid eccentric reaming. A curved femoral broach handle is used to follow the direction of the femur and improve the surgeon’s work (Figs. 8.13 and 8.14).

Figure 8.13

Curved femoral broach handles.

Intra-operative Digital Imaging

Figure 8.14

Curved acetabular reamer.

8.3 Intra-operative Digital Imaging Regarding the intra-operative use of radiographic images, the literature reports different opinions. Hambright always uses the radioscope during surgery [13]. He claims that the use of intraoperative digital imaging in THA improves the accuracy of the positioning of the components at THA without adding a substantial amount of time to the operation. Beamer et al. [14] had previously shown signiϐicant improvement of acetabular alignment using intraoperative ϐluoroscopy. Jennings [15] and Ji [16] also state that the use of radiographic images improves the orientation of the cup, while Leucht [17] describes the signiϐicant advantage with the use of the image intensiϐier in obtaining the eumetry of the limbs. Homma [18] has shown how intra-operative radiographic control improves the

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learning curve in the implantation of the prosthesis in the anterior approach. Do not forget that there are authors who do not use the image intensiϐier [19]. Other authors have highlighted the risk of contamination of the sterile surgical ϐield [20] and exposure of room staff and the patient to radiation [21]. The use of the ampliϐier does not produce, instead, a signiϐicant increase in operative time, and the time of use of ϐluoroscopy decreases as the learning curve progresses [22].

8.4

Advantages of Anterior Hip Replacement

The growing interest in minimally invasive surgical approaches and tissue sparing has given strength to the direct anterior approach. The idea of a reduction in post-operative pain, a decrease in blood loss, faster discharge and better functional recovery remains, too, if there is no scientiϐic evidence in the literature to date that demonstrates the superiority of the anterior approach compared to other traditional hip accesses in terms of functional outcomes, implant survival and rate of long-term complications [23]. Connolly highlights a reduction in pain in the immediate post-operative period if the previous approach is compared to other surgical approaches, including minimally invasive variants [24]. Matta demonstrates how the average bleeding in a series of 437 hip prostheses implanted with the anterior approach is a result of 350 ml, a value that testiϐies to the conservative nature of the approach if conducted by expert hands [25]. Barnett et al. performed a study of 5090 cases of hip prostheses performed with the anterior approach [26]. There were 41 intra-operative femur fractures, including 29 calcar fractures, 9 greater trochanter fractures and 3 femoral shaft fractures. There were 7 post-operative femur fractures, including 3 greater trochanter fractures, 2 calcar fractures and 2 femur fractures. Other complications included 15 superϐicial infections, 5 deep infections, 12 dislocations, 8 haematomas, 3 cases of cellulitis, 2 sciatic nerve palsies, 1 peroneal nerve palsy and 1 intrapelvic bleed. The nonsurgical complication rate was 1.4%. Deep vein thrombosis occurred in 0.3% of cases. LeRoy et al. [27] have evaluated how the anterior approach to THA is associated with a signiϐicantly shorter length of hospital stay and a lower rate of discharge to rehab than

Conclusions

the posterior approach. The dislocation rate of anterior approach prostheses has always been reduced, probably for the greater intrinsic stability due to the lack of detachment of short external rotators and reduced trauma on the abductors hip. There are several works that conϐirm these data [28, 29]. The growing increase of prosthetic implants in young people has raised the problem of the aesthetic rendering of surgical scars; the description of the ‘bikini’ skin incision by Leunig [9] resolves mostly visibility problems (in the case of lateral or posterior accesses) and frequently cicatricial hypertrophy (in the case of the classic anterior approach).

8.5 Disadvantages of Anterior Hip Replacement The disadvantages of this surgical approach are related to the movement of the limb during extension and external rotation manoeuvres [30]. These can cause fracture of the greater trochanter or the femoral shaft. The lateral cutaneous femoral nerve can be traumatised by the use of retractors, while the tensor fasciae latae muscle can be damaged by incorrect use of retractors [31]. Abnormal haematomas can occur at an incorrect ligation of the circumϐlex vessels [32]. Using a small surgical wound can cause bruising due to the instruments that touch the skin. These manoeuvres are more forced in obese subjects, who therefore have the highest incidence of complications [33]. However, we cannot fail to mention the possible complications, although a few have been registered (in 2%–4% of cases) and are related to the learning curve [34].

8.6

Conclusions

The advantage of the anterior approach is that the normal gait is not dependent on tendon healing, since no tendons have been removed and repaired, as they have in the direct lateral approach and posterolateral approach. Therefore, it is possible to discourse about ‘tissue-sparing surgery’. This is not a particular technique but a ‘surgical philosophy’, consisting in a maximum respect for soft

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tissues and bone, including reduction of operative invasiveness and the use of minimally invasive surgical solutions.

References 1. Hueter C. Fünfte abtheilung: die verletzung und krankheiten des hüftgelenkes, neunundzwanzigstes capitel. In Hueter C, (ed.) Grundriss der chirurgie, 2nd Ed. Leipzig: FCW Vogel, 1883; pp. 129–200. 2. Smith-Petersen MN. A new supra-articular subperiosteal approach to the hip joint. J Bone Joint Surg Am, 1917; s2–15:592–595. 3. Judet J, Judet R. The use of an artiϐicial femoral head for arthroplasty of the hip joint. J Bone Joint Surg Br, 1950; 32B:166–173. 4. Judet J, Judet H. Voie d’abord anterieure dans l’arthroplastie totale de la hanche. Presse Med, 1985; 14:1031–1033. 5. Matta JM, Shahrdar C, Ferguson T. Single-incision anterior approach for total hip arthroplasty on an orthopaedic table. Clin Orthop Relat Res, 2005; 441:115–124. 6. Laude F. Total hip arthroplasty through an anterior Hueter minimally invasive approach. Interact Surg, 2006; 1:5–11. 7. Moreau P. Minimally invasive total hip arthroplasty using Hueter’s direct anterior approach. Eur J Orthop Surg Traumatol, 2018; 28(5):771–779. 8. Lesur E, Laude F. The minimally invasive trend in total hip arthroplasty through the anterior approach. Encyclopédie Médico-Chirurgicale, 2004; 7B:44–66. 9. Leunig M, Hutmacher JE, Ricciardi BF, Impellizzeri FM, Rüdiger HA, Naal FD. Skin crease ‘bikini’ incision for the direct anterior approach in total hip arthroplasty: a two- to four-year comparative study in 964 patients. Bone Joint J, 2018; 100B(7):853–861. 10. Tian S, Goswami K, Manrique J, Blevins K, Azboy I, Hozack WJ. Direct anterior approach total hip arthroplasty using a morphometrically optimized femoral stem, a conventional operating table, without ϐluoroscopy. J Arthroplasty, 2019; 34(2):327–332. 11. Galakatos GR. Direct anterior total hip arthroplasty. Mo Med, 2018; 115(6):537–541. 12. Capone A, Podda D, Civinini R, Gusso MI. The role of dedicated instrumentation in total hip arthroplasty. J Orthop Traumatol, 2008; 9(2):109–115.

References

13. Hambright D, Hellman M, Barrack R. Intra-operative digital imaging: assuring the alignment of components when undertaking total hip arthroplasty. Bone Joint J, 2018; 100B(1 Suppl A):36–43. 14. Beamer BS, Morgan JH, Barr C, Weaver MJ, Vrahas MS. Does ϐluoroscopy improve acetabular component placement in total hip arthroplasty? Clin Orthop Relat Res 2014; 472:3953–3962. 15. Jenn ings JD, Iorio J, Kleiner MT, et al. Intraoperative ϐluoroscopy improves component position during anterior hip arthroplasty. Orthopedics, 2015; 38:e970–e975. 16. Ji W, Stewart N. Fluoroscopy assessment during anterior minimally invasive hip replacement is more accurate than with the posterior approach. Int Orthop, 2016; 40:21–27. 17. Leucht P, Huddleston HG, Bellino MJ, et al. Does intraoperative ϐluoroscopy optimize limb length and the precision of acetabular positioning in primary THA? Orthopedics, 2015; 38:e380–e386. 18. Homma Y, Baba T, Kobayashi H, et al. Safety in early experience with a direct anterior approach using ϐluoroscopic guidance with manual leg control for primary total hip arthroplasty: a consecutive one hundred and twenty case series. Int Orthop, 2016; 40(12):2487–2494. 19. Leunig M, Faas M, von Knoch F, et al. Skin crease ‘bikini’ incision for anterior approach total hip arthroplasty: surgical technique and preliminary results. Clin Orthop Relat Res, 2013; 471:2245–2252. 20. Peters PG, Laughlin RT, Markert RJ, et al. Timing of C-arm drape contamination. Surg Infect, 2012; 13:110–113. 21. Pomeroy CL, Mason JB, Fehring TK, Masonis JL, Curtin BM. Radiation exposure during ϐluoro-assisted direct anterior total hip arthroplasty. J Arthroplasty, 2016; 31(8):1742–1745. 22. Penenberg BL, Woehnl A. Intraoperative digital radiography: an opportunity to assure. Semin Arthroplasty, 2014; 25:130–134. 23. Petis S, Howard JL, Lanting BL, Vasarhelyi EM. Surgical approach in primary total hip arthroplasty: anatomy, technique and clinical outcomes. Can J Surg, 2015; 58(2):128–139. 24. Connolly KP, Kamath AF. Direct anterior total hip arthroplasty: comparative outcomes and contemporary results. World J Orthop, 2016; 7:94–101. 25. Matta JM, Shahrdar C, Ferguson T. Single-incision anterior approach for total hip arthroplasty on an orthopaedic table. Clin Orthop Relat Res, 2005; 441:115–124.

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26. Barnett SL, Peters DJ, Hamilton WG, Ziran NM, Gorab RS, Matta JM. Is the anterior approach safe? Early complication rate associated with 5090 consecutive primary total hip arthroplasty procedures performed using the anterior approach. J Arthroplasty, 2016; 31(10):2291–2294. 27. LeRoy TE, Hayden BL, Desmarais J, Menendez ME, Ward D. Early outcome comparison of the posterior approach and the superior approach for primary total hip arthroplasty. Arthroplast Today, 2020; 6(3):508–512. 28. Sariali E, Leonard P, Mamoudy P. Dislocation after total hip arthroplasty using Hueter anterior approach. J Arthroplasty, 2008; 23:266–272. 29. Chen W, Sun JN, Zhang Y, Zhang Y, Chen XY, Feng S. Direct anterior versus posterolateral approaches for clinical outcomes after total hip arthroplasty: a systematic review and meta-analysis. J Orthop Surg Res, 2020; 15(1):231. 30. De Geest T, Vansintjan P, De Loore G. Direct anterior total hip arthroplasty: complications and early outcome in a series of 300 cases. Acta Orthop Belg, 2013; 79(2):166–173. 31. Jewett BA, Collis DK. High complication rate with anterior total hip arthroplasties on a fracture table. Clin Orthop Relat Res, 2011; 469(2):503–507. 32. Lee GC, Marconi D. Complications following direct anterior hip procedures: costs to both patients and surgeons. J Arthroplasty, 2015; 30(9 Suppl):98–101. 33. Ricciardi A, Geraci A. Anterior minimally invasive surgery for hip replacement in obese patients. Minerva Ortop Traumatol, 2017; 68(3):131–138. 34. Seng BE, Berend KR, Ajluni AF, Lombardi AV Jr. Anterior-supine minimally invasive total hip arthroplasty: deϐining the learning curve. Orthop Clin North Am, 2009; 40(3):343–350.

Chapter 9

Periprosthetic Fractures of the Hip Joint

Shibu Krishnan, Gurdeep S. Biring and Arvind Vijapur Buckinghamshire Healthcare NHS Trust, Stoke Mandeville Hospital, Mandeville Road, Aylesbury, Buckinghamshire, HP21 8AL, UK [email protected], [email protected], [email protected]

9.1

Introduction

A periprosthetic hip fracture occurs around a hip replacement prosthesis. Fractures occurring around a hip implant, such as internal ϐixation devices, are not considered in this chapter. Periprosthetic hip fractures can occur either on the femoral side or on the acetabular side, the femoral side being more common. Currently, there is an epidemic of these fractures in the developed world, contributed by an increased number of joint replacements, life expectancy, expectations and activity level. Treatment of periprosthetic fractures can be challenging. This is because the fracture may be of a complex pattern, a poor soft-tissue envelope secondary to multiple previous surgeries, deϐicient bone stock because of osteoporosis and previous surgeries and signiϐicant associated comorbidities in these

The Hip Joint Edited by K. Mohan Iyer

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ISBN 978-981-4877-51-0 (Hardcover), 978-1-003-16546-0 (eBook)

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Periprosthetic Fractures of the Hip Joint

elderly group of patients. Rehabilitation can be daunting due to poor prefracture mobility, varying mental status, multiple joint disease, generalised muscle weakness associated with old age, signiϐicant comorbidities and complex social circumstances. The aims of surgical management include the restoration of functional status, durable reconstruction of the hip and femur and minimisation of medical and psychosocial complications.

9.2

Epidemiology

The incidence of periprosthetic fractures [1]: ∑ 0.9% following primary total hip replacement (THR) ∑ 4.2% following revision THR ∑ Intra-operative fractures: o 0.4% of primary cemented THRs o 3.5% of primary uncemented THRs The tip of the femoral stem is fractured most commonly, and 80% of all periprosthetic fractures are Vancouver type B fractures. The cumulative probability of a periprosthetic hip fracture is 1.9% at 1 year, 3.8% at 5 years, 6.4% at 10 years and 11.4% at 20 years [2]. The incidence of periprosthetic femoral fractures during surgery has been reported as 1.7%, with a statistically greater risk in female patients and those older than 65 years and with uncemented hips [2]. The reported incidence of intra-operative periprosthetic fracture during revision arthroplasty is 12% and 3 times more with uncemented stems [2]. The intra-operative periprosthetic fracture can happen while removing the previous prosthesis (30.7%), during insertion of femoral component (34.5%) or during trial reduction (22.5%) [2]. The mortality rate after periprosthetic hip fracture treatment within 1 year is high (11% to 25%) and is almost similar to that of elderly patients treated for hip fractures [3]. Likewise, a delay in surgical intervention of more than 2 days signiϐicantly increases the mortality risk within 1 year. One-year mortality is signiϐicantly less in patients who have undergone revision arthroplasty surgery than patients who had open reduction and internal ϐixation for Vancouver type B fractures [3].

Classification of Periprosthetic Fractures

9.2.1

Risk factors

Risk factors for intra-operative fractures: ∑ Patient-related risk factors: o Increased age o Female sex o Post-traumatic arthritis o Rheumatoid arthritis o Osteoporosis o Deformed bone, including anatomical variations like developmental dysplasia, narrow femoral canal and champagne ϐlute proximal femur, protrusio acetabuli o Hardware removal needed prior to hip replacement o Cortical bone defects from previous surgery o High body mass index o Cervical myelopathy [4] o Prior radiation o Revision procedure ∑ Surgery and implant-related factors o Direct anterior approach and age [5] o Hardinge approach and younger age (greater risk for calcar fractures) [6] o Poor surgical technique o Cementless prosthesis o Elliptical modular components o Impaction bone grafting of the femur o Risk factors for post-operative fractures: trauma, age more than 70 years, osteoporosis, osteolysis and aseptic loosening, and stress raisers (e.g., tip of the stem, cortical breach during revision surgery)

9.3 Classification of Periprosthetic Fractures Many classiϐications for both acetabular and femoral periprosthetic fractures exist. An ideal classiϐication system should guide in treatment, estimate prognosis and allow meaningful comparison between different surgical techniques and outcomes in different

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centres. The timing of the fracture and the anatomical site are typically used to deϐine and guide management. Fractures based on location: ∑ Acetabular fractures: o Intra-operative: Ŷ Involvement of the acetabular wall or the columns Ŷ Stability of the fracture o Post-operative: Ŷ Type I: Radiographically stable acetabular component, non-operative management Ŷ Type II: Radiographically unstable acetabular component, operative management ∑ Femur fractures

9.3.1 The Vancouver Classification System The Vancouver classiϐication system is the most common classiϐication system. Duncan and Masri devised this post-operative classiϐication in 1995 [7] and more recently reported an intraoperative classiϐication [8]. The Vancouver classiϐication system incorporates three most important elements: fracture location (whether the fracture involves the bone supporting the prosthesis or is distant to it), implant stability (whether the bone–implant interface was stable prior to fracture and remained stable after the fracture) and the quality of bone stock (whether the bone stock is sufϐicient to permit revision or requires reconstruction). Three anatomical types are deϐined on the basis of the site of the fracture [7]: A type A fracture is located in trochanteric area and has got minimal inϐluence on the implant ϐixation. A type B fracture occurs around or just distal to femoral stem and is further divided on the basis of stability of the implant and adequacy of bone stock. Type C fractures are those distal to the tip of the stem. Surgical management of type C fractures can be considered independent of the presence of a femoral prosthesis. If a fracture occurs through the cement mantle distal to the stem which is well ϐixed, then it is classiϐied as a B1 fracture. If the fracture passes through the cement mantle around the stem, it is classiϐied as B2 irrespective of whether the stem is well ϐixed before the fracture.

Classification of Periprosthetic Fractures

ƒ…‘—˜‡”…Žƒ••‹ϐ‹…ƒ–‹‘•›•–‡ǣ ∑ Type A: Fracture occurring around the trochanteric region o AG: Fractures of the greater trochanter (Fig. 9.1) o AL: Fractures of the lesser trochanter

Figure 9.1

Vancouver type AG fracture. Courtesy of Shibu Krishnan.

∑ Type B: Diaphyseal fractures around or just distal to the stem o B1: Fractures in which the stem is stable o B2: Fractures in which the stem is unstable (Fig. 9.2)

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o B3: Fractures in which the stem is unstable and the bone stock is inadequate

Figure 9.2

Vancouver type B2 fracture. Courtesy of Shibu Krishnan.

∑ Type C: Fractures well distal to the stem such that surgical ϐixation can be considered independent of the presence of the hip stem ∑ Type D: An interprosthetic fracture of the femur, that is, fracture of the femur between a hip and knee joint replacement ∑ Type E: A fracture of both the femur and the pelvis following hip replacement ”ƒ…–—”‡•„ƒ•‡†‘–‹‹‰ǣ ∑ Post-operative o Acetabular fractures o Femoral fractures ∑ Intra-operative o Femoral fractures The modiϐied Vancouver classiϐication for intra-operative periprosthetic femur fractures uses the same A, B and C types as for post-operative fractures.

Classification of Periprosthetic Fractures

∑ Type A: Fracture conϐined to the trochanteric region

∑ Type B: Fracture involving the diaphysis of the femur ∑ Type C: Fracture occurring distal to the diaphysis In addition, they use subtypes 1 to 3 based on cortical perforation, undisplaced fracture and displaced fracture, respectively. ∑ Subtype 1: Simple cortical perforation, occurs during cement removal or at the time of reaming for canal preparation ∑ Subtype 2: Undisplaced linear fracture, typically occurs in the metaphysis of the proximal diaphysis at the time of canal preparation due to increased hoop stress ∑ Subtype 3: Unstable or displaced fracture pattern, typically occurs with forceful impaction If a fracture is identiϐied at the time of operation, the treatment follows the algorithm given in Table 9.1. Table 9.1

Algorithm for treatment of fracture identified at the time of operation

›’‡

Fracture pattern

‡…‘‡†‡†–”‡ƒ–‡–

A1

Metaphyseal cortical perforation

Bone graft from acetabular reamings

A2

Nondisplaced linear crack

Stabilisation with cerclage wire, screws or trochanteric claw plate

A3

Displaced/Unstable fracture of the greater trochanter/ proximal femur

Cerclage wire, cable plate, or trochanteric claw plate before cementation or uncemented implant with a fully coated stem

B1

Diaphyseal cortical perforation

Revision of the femoral component bypassing by two cortical diameters width +/– cortical strut graft/plate

B2

Nondisplaced linear crack

Wiring for stable implant or bypass with a stem +/– cortical allograft +/– plate and screws for unstable implant

B3

Displaced fracture of the mid-shaft femur

ORIF of the fracture and bypass with a longer stem (Continued)

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Table 9.1

(Continued)

›’‡

Fracture pattern

‡…‘‡†‡†–”‡ƒ–‡–

C1

Cortical perforation

Grafted or bypass with a longer stem and cortical strut graft

C2

Nondisplaced crack extending just above the knee

Cerclage wire +/– cortical strut graft

C3

Diaphyseal fracture of the distal femur that cannot be bypassed with a femoral stem

ORIF with plate +/– cortical strut graft

9.3.2 The Unified Classification System More recently the A–O group has proposed a uniϐied classiϐication system (UCS) [8] for management of periprosthetic fractures. In this classiϐication Duncan et al. combined and uniϐied, and expanded, where required, thereby acknowledging the biological and biomechanical factors which are common to all fractures following joint replacement, as well as the important inϐluence of component loosening and bone loss. The different fracture types of the UCS have been devised and a mnemonic developed to help remember the system (Table 9.2): ∑ ∑ ∑ ∑ ∑ ∑

Type A: Apophyseal Type B: Bed of the implant Type C: Clear of the implant Type D: Dividing the bone between two implants Type E: Each of two bones supporting one arthroplasty Type F: Facing and articulating with a hemiarthroplasty

Table 9.2

Unified classification system …‡–ƒ„—Ž—Ȁ Pelvis

›’‡ A Apophyseal/ extra-articular

‡—”ǡ’”‘š‹ƒŽ

A1 Avulsion of

Anterior inferior/ superior iliac spine

Greater trochanter

A2 Avulsion of

Ischial tuberosity

Lesser trochanter

Classification of Periprosthetic Fractures

…‡–ƒ„—Ž—Ȁ Pelvis

›’‡ B Bed of implant

B1 Acetabular rim or Prosthesis stable, good good bone bone

B2 Prosthesis loose, good bone

B3 Prosthesis loose, poor bone stock

C Clear of the implant D Dividing the bone between two implants or interprosthetic/ intercalary E Each of the two bones supporting one arthroplasty F Facing and articulating with a hemiarthroplasty

Loose cup, good bone

‡—”ǡ’”‘š‹ƒŽ Stem stable, good bone Surface replacement: femoral neck Loose stem, good bone Surface replacement: loose implant, no proximal bone loss

Loose stem, poor Loose cup, poor bone, defect bone, bone defect, pelvic discontinuity Surface replacement: loose implant, bone loss Pelvic/Acetabular fractures distant to the implant

Distal to the implant and cement mantle

Pelvic fracture between bilateral THRs

Between hip and knee joint replacements, close to the hip

Pelvis and femur

– Fracture of the acetabulum articulating with the femoral hemiarthroplasty

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With this uniϐied system the complexity of all aspects of periprosthetic fractures is expected to become standardised and allows comparisons globally for this difϐicult group of patients.

9.4 Clinical Diagnosis of Periprosthetic

Fractures

Intra-operative periprosthetic fractures of the femur can be diagnosed by direct observation. This requires circumferential exposure of the calcar or intra-operative radiographs if a fracture is suspected. Intra-operative fractures can occur at the time of retrieval of the prosthesis, at the time of canal preparation or at the time of prosthesis insertion. A change in the pitch while using instruments, the sudden reduction in the force required when a broach or rasp is used or advancement of the implant beyond the planned level of placement, a sudden loss of cup stability, etc., should raise suspicion of a fracture. Post-operative fractures are associated with minimal trauma or a fall from standing height. The clinical presentation will be sudden onset of pain and deformity after a fall.

9.4.1

Investigations

Plain radiographs of the hip and whole femur are often all that is necessary for obtaining adequate information on these fractures. Comparison of previous radiographs, especially the earliest available ones, is useful to assess any prior implant loosening, osteolysis or implant migration which would inϐluence the decision to revise components. Special views such as Judet’s views of the acetabulum may be required to evaluate the integrity of columns in cases of acetabular fractures. Computed tomography (CT) scans, including 3D reconstruction, could give additional information on the acetabular bone stock, integrity of the columns and loosening of the femoral stem. Blood inϐlammatory markers as well as aspiration of the hip joint might be indicated to exclude infection. Lindahal et al. [9] demonstrated that Vancouver B1 fracture had signiϐicant risk of failure, and the strongest negative predictor was the use of single-plate ϐixation. The most common reasons for failure

Treatment

in this group were loosening of the femoral prosthesis, non-union or re-fracture. They concluded that the probable reason for the high rate of failure is due to underdiagnosis of loose implants and wrongly classifying the fracture as B1 rather than B2. If in doubt about the stability of the prosthesis, intra-operative stability testing should be undertaken. However, intra-operative stability testing is often technically challenging since this adds conϐlict to patient positioning and increases the risk for component revision to address instability.

9.5 Treatment 9.5.1

Surgical Approach

Special attention should be given to soft-tissue management. Previous surgical scars, when available, should be used. An appropriate skin bridge should be maintained to avoid skin necrosis. The approach should be extensile and facilitate the removal of components and placement of ϐixation devices. The sciatic nerve should be identiϐied and must be protected throughout the surgery. Excision of scar tissue around the sciatic nerve and its mobilisation should be considered to minimise the risk of sciatic nerve palsy.

9.5.1.1

Pre-operative workup and planning

The main aims of the treatment are to restore anatomical alignment and leg length and achieve fracture union, prosthesis stability and an early return to premorbid functional status, thereby minimising morbidity and mortality. A sound preplanning which anticipates all potential pitfalls to create backup plans is necessary to achieve these surgical goals and help deal with any intra-operative or postoperative complications. A thorough medical history, medical and anaesthetic review should be obtained to optimise the patient for surgery. Bone deϐiciency, deformity and speciϐic details on existing hardware should be noted and considered when devising a surgical plan. Templating is performed. For fracture ϐixation, the inventory considered should include locking plates, cable plates, hybrid locking and cable plates, cortical strut grafts or a combination of these, femoral head allografts for bone grafting, etc. If a femoral

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Periprosthetic Fractures of the Hip Joint

revision is planned, length of the stem, geometry and type of the stem should be determined. For acetabular revisions inventory considered may include column plates, femoral head allografts, augments, buttresses, jumbo cups, anti-protrusio cages, etc. When there is pelvic discontinuity the options include triϐlange cups, off the shelf or custom ones, acetabular cages, cup cage construct, etc. Soft-tissue repair/reconstruction options considered should include synthetic scaffolds to augment repair, muscle/fascial ϐlaps, etc. Considerations to ensure stability of the joint include use of large heads, dual-mobility liners, fully constrained liners, elevated rims and lip augmentation devices for the acetabular liner, adequate offset reconstruction of the femoral component, etc.

9.5.2 Non-operative Treatment This may be indicated in some Vancouver type A fractures or when the patient’s general condition precludes a prolonged surgical procedure. This may also be considered for patients with poor premorbid physical function, especially if they are non-ambulatory. Ensuing prolonged recumbency predisposes patients to a higher risk of complications such as pressure ulcers, thromboembolism, chest infection, urinary infection, knee joint contractures, mal-union, nonunion and shortening of the leg.

9.6 Surgical Management of Periprosthetic Acetabular Fractures The goal of operative treatment of acetabular fractures is to obtain a lasting, stable and well-positioned acetabular cup. ∑ Type I: Acetabular fractures with a stable, well-ϐixed acetabular prosthesis. The recommended treatment is to minimise loading and allow the fracture to heal prior to allowing the patient to bear weight fully on that leg. Later revision of the acetabular component, when necessary, could be technically easier once the fracture has healed. ∑ Type II: Acetabular fractures with an unstable prosthesis: This would require revision, and the technical complexity will depend on the type of acetabular deϐiciency and the

Surgical Management of Periprosthetic Acetabular Fractures

integrity of the acetabular columns. A range of acetabular reconstruction options are available, such as bone-grafting the defects, using a multihole uncemented component stabilised using screws, using acetabular augments, using ‘jumbo cups’ with stabilisation of fracture in a distracted position, using acetabular cages to stabilise the columns, using cemented acetabular components, and using cup-cage constructs (Figs. 9.3 and 9.4).

Figure 9.3 Ŷ ĞdžƚƌĞŵĞ ĐĂƐĞ ŽĨ ŝŶƚƌĂͲŽƉĞƌĂƟǀĞ ƚLJƉĞ // ĂĐĞƚĂďƵůĂƌ ĨƌĂĐƚƵƌĞ with an unstable acetabular component transferred to our centre for further management. Courtesy of Gurdeep Biring.

Figure 9.4 Post-operative radiograph after surgical reconstruction by authors, demonstrating stabilisation of the columns, bone grafting, and reconstruction using a cup-cage construct. Courtesy of Gurdeep Biring.

201

Stabilise both columns using plate +/- lag screws

Acetabular shell - unstable

Acetabular column fracture

Plate fixation of the column

Acetabular shell - stable

Management of intra-operative periprosthetic acetabular fractures.

Plate fixation of the fracture

Additional screws to stabilise the acetabular shell

Figure 9.5

Acetabular shell - unstable

Acetabular shell - stable

Acetabular wall fracture

Intra-operative acetabular fractures

202 Periprosthetic Fractures of the Hip Joint

Figure 9.6

Non-union of pain Surgical fixation

Restricted weight bearing upto 8 weeks

ORIF

Surgical fixation and radiologically unstable shell

Pelvic ring - stable

Significant displacement of the fracture

Pelvic ring - unstable

Management of post-operative periprosthetic acetabular fractures.

Significant fixation +/- bone graft

Restricted weight bearing for upto 8 weeks

Displacement of fracture - minimal

Both clinically and radiologically stable shell

Post-operative acetabular periprosthetic fractures

Surgical Management of Periprosthetic Acetabular Fractures 203

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Periprosthetic Fractures of the Hip Joint

Here are two ϐlowcharts demonstrating the management of periprosthetic acetabular fractures (Figs. 9.5 and 9.6).

9.6.1 Surgical Considerations in the Management of Periprosthetic Femoral Fractures 9.6.1.1

Treatment of intra-operative femur fractures

The Vancouver classiϐication system for intra-operative periprosthetic femur fractures can guide the appropriate management plan. ∑ Type A fractures: Fractures are conϐined to the trochanteric region without extension into the diaphysis o A1: Cortical perforation is inherently stable and is best managed by bypassing the perforation with a long stem. The construct is augmented by autogenous reamings or bone grafts from the femoral head, which are easily available. o A2: Undisplaced linear cracks are best treated by removal of the stem, cerclage wiring of the metaphysis and insertion of the stem. This will prevent propagation of the fracture and subsequent subsidence of the prosthesis. A decrease in the pitch frequency happens routinely when a stem or broach insertion and demonstrates engagement. Once this decrease in pitch is observed, continued forceful hammering should be stopped to avoid intra-operative fracture. Also, care should be taken to avoid aggressive hammering of the stem against the cortical bone of the calcar once the stem has seated fully. o A3: Displaced fractures of the greater trochanter. Intra-operative greater trochanter fracture are ideally stabilised with trochanteric claw plates. The length of the device and the number of cables depend on the fracture conϐiguration. ∑ Type B fractures: Fractures occur around or just distal to the tip of the implant. They commonly occur during the implantation of a diaphyseal ϐitting of curved or straight cylindrical stem. There will be 44% reduction in the original strength of the

Surgical Management of Periprosthetic Acetabular Fractures

femur if there is a cortical perforation. A stem long enough to bypass at least two cortical diameters is needed to provide adequate torsional strength [10]. o B1: Cortical perforation. The area of perforation should be bypassed with a longer stem by two cortical diameters [10]. If it is a revision scenario and a longer stem is not possible, then the cortex should be augmented with a cortical strut graft or plate. o B2: Undisplaced linear crack. If detected intra-operatively, the fracture should be stabilised with cerclage wire and the fracture should be bypassed with a longer stem. A cortical strut graft can be used if the fracture cannot by bypassed by a long femoral stem or the bone stock is poor [11]. This should be followed by restricted weight-bearing for at least for 6 weeks after surgery. o B3: Displaced linear cracks. These should be treated with cerclage wiring and a longer stem which bypasses the distal-most extent of the fracture by at least two cortical diameters [10]. ∑ Type C fractures: Type C fractures extend beyond the tip of the stem and can include the distal metaphyseal region [12]. These types of fractures occur during cement removal in a revision scenario or at the time of canal preparation. o C1: Cortical perforation. Bone grafting and protected weight bearing should be done. o C2: Undisplaced linear cracks should be treated with cerclage wire with or without a cortical strut graft. o C3: Displaced fractures should be surgically managed with open reduction and internal ϐixation. A plate-andscrew construct, onlay cortical struts or ac ombination of both can be used.

9.6.1.2 Treatment of post-operative femur fractures Type A fractures: Only a small proportion of these fractures require surgical intervention since the majority of them would regain their prefracture functional status with non-operative management. Patients are managed on the basis of their functional expectations.

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Periprosthetic Fractures of the Hip Joint

AG fractures: Nondisplaced fractures could be managed nonoperatively. They can be mobilised with protected weight-bearing for 6 to 12 weeks. Hip abduction should be avoided till the fracture is healed radiologically. Displaced fractures might require open reduction and ϐixation using special trochanteric hook-cable plates and cables/screws or cerclage wire to regain abductor muscle function. There may be associated osteolysis of the proximal femur, which may require bone grafting along with revision of the acetabular liner, if the osteolysis is secondary to wear of the acetabular liner. A displacement of 2 cm or more or osteolytic destruction may be an indication of surgical ϐixation [13]. AL fractures: They could be managed non-operatively since they are unlikely to produce functional impairment unless the fractures compromise prosthetic stability, which occurs if the calcar fracture line extends distally onto the shaft. Such fractures may require stabilisation using cerclage wire or revision of the femoral component along with stabilisation of the fracture segment if the prosthesis is deemed unstable. B1 fractures: These fractures are treated by ORIF using extramedullary ϐixation techniques, including plates, screws (locking and nonlocking), cables, cerclage wire and cortical strut allografts. Bone grafting of the fracture site is also considered. A variety of cable plating systems is available, which allow screws, cables or cerclage wire on either segments. Cables are shown to be stronger than cerclage wire. Cables resist bending loads satisfactorily. Cerclage wire or cables are shown to be less mechanically sound than unicortical screws in offering torsional and anteroposterior (AP) stability. At least six cables are needed in the absence of a unicortical screw to improve AP and rotational stability. Besides, cables produce more surgical trauma and increase surgical time. Therefore fewer cables and more locking screws are preferred. Differentiating a B1 from a B2 fracture can be difϐicult on the basis of pre-operative evaluation alone. Intra-operative stability testing of the femoral stem may then be performed through the fracture site, if the stem is exposed, or by performing an arthrotomy and testing stability after dislocating the hip [9]. However, this adds additional technical challenges to the procedure.

Surgical Management of Periprosthetic Acetabular Fractures

Current evidence supports the use of a lateral locking plate with proximal unicortical screws and cables, distal bicortical locking screw ϐixation (especially in poor-quality bone) and an onlay cortical strut allograft ϐixed by cables and positioned on the medial femoral cortex (Fig. 9.7). In a biomechanical study using four different constructs for the ϐixation of periprosthtic femoral shaft fractures, construct using a nonlocking cable plate with an allograft strut, cables and screws demonstrated superior stiffness of the construct around a stable femoral component of a total hip replacement [14]. The use of uniplanar or biplanar plates would also lead to satisfactory healing in selected cases. A noncontact bridging plate system provides a higher rate of load failure and is the preferred plating system when stability and load capacity are needed immediately after surgery [14]. The minimum number of ϐixation points required for strut allografts has been shown as three each on proximal and distal segments. The allograft strut essentially acts as biological plates. The advantages of strut grafts include biological ϐixation modality; osteoconductive properties for fracture healing; and augmentation of the often deϐicient host’s bone stock, thereby increasing the strength of the bone once the graft has been incorporated. The allograft struts also minimises stress shielding since its modulus of elasticity is near to the patient’s bone. The strut allograft augmentation for Vancouver B1 fracture has got a better outcome than plate ϐixation alone by adding mechanical stability and enhancing biological healing [15, 16]. The disadvantages of cortical strut grafts include their limited availability, high cost, potential for disease transmission and increased risk of infection. Minimally invasive plate osteosynthesis (MIPO) can be used for B1 fractures. The plate should be long enough to overlap the prosthesis with as much length as would be possible. This is technically challenging. The main advantage of this technique is preserving the soft-tissue attachment and the blood supply and thus minimising surgical morbidity and optimising bone healing. Meticulous softtissue techniques should be used to avoid devascularisation of the bone [17].

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Periprosthetic Fractures of the Hip Joint

Figure 9.7 B1 fracture treated by the author using a cable-locking plate and a cortical strut allograft. Courtesy of Shibu Krishnan.

B2 fractures: In a B2 fracture, the stem will be loose. It is best managed by revising in to a longer stem prosthesis which bypasses the fracture site. About 75% to 82% of all B fractures are reported as having a loose femoral component. The goals of surgical treatment are to restore long-term implant stability and to allow fracture healing. The choice of revision arthroplasty depends on the patient’s bone stock. The long-stem revision could be using either a cemented or an uncemented stem. A cemented stem has the disadvantage of ϐilling the fracture site with cement, thus impeding the fracturehealing process. Also, reϐilling the proximal femur with cement after removal of a cemented stem provides a poor cement mantle. There is a lack of metaphysical support because of fracture. A long uncemented stem provides distal ϐixation, while allowing the proximal fracture segments to be wrapped around the proximal aspect of the stem. A tapered, ϐluted, modular, uncemented stem would provide axial (taper) and rotational stability (ϐlutes), while allowing adjustments to restore the leg length and soft-tissue tension. The use of a modular prosthesis facilitates the re-creation of original biomechanics of the hip with the freedom of re-establishing

Surgical Management of Periprosthetic Acetabular Fractures

the length and femoral version independently. Neumann et al. [18], in their series of 55 patients, concluded that the use of a distally ϐixed modular stem is reliable when treating B2 and B3 fractures [19]. Subsidence of the stem requiring revision was noted in 4% of patients in their series. A cortical strut allograft may also be used in some cases to augment stability of the construct (Fig. 9.8). The long stem should bypass the fracture by at least two cortical diameters of the femur with at least 4 cm of the diaphyseal ϐit [19].

Figure 9.8 B2 fracture treated by the author, with revision of the femoral component and a cable-locking plate and allograft strut cortical grafts. Longstem revision was made difficult because of the distal comminution, which required allograft cortical strut reconstruction. This patient could not be allowed to bear weight for 3 months after the surgery. Courtesy of Shibu Krishnan.

The reported complication rates are higher for cemented revision stems as opposed to uncemented stems in managing B2 fractures. Cemented revisions [20] have up to 62% complication rates with 38% loosening and 24% of miscellaneous complications, including infection, dislocation and trochanteric non-union. Uncemented revisions report up to 34% complications (18% subsidence and the rest miscellaneous complications). An alternative distal ϐixation technique involves the use of a distally locked stem. The designs include those that do not allow

209

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Periprosthetic Fractures of the Hip Joint

bone ingrowth (e.g., the Kent hip [Biomet, UK], the Cannulock stem [Orthodesign, UK], and those which allow it [Reef stem, Depuy]) and the screw ϐixation is a temporary measure for stabilisation. Their main advantages include the ability to bear weight earlier, improved intra-operative control of the leg length and rotation. They are especially useful for cases with signiϐicant proximal bone loss where diaphysal ϐixation could be otherwise unsatisfactory and in the management of infected periprosthetic femoral fractures. B3 fractures: The proximal femur bone stock is insufϐicient to support the prosthetic reconstruction, which should then be based on adequate distal ϐixation to provide rotational, angular and axial support. Reconstruction options include: ∑ Modular, long, ϐluted, cementless femoral stem with distal ϐixation and wrap-around of the proximal femur bone augmented by allograft struts ∑ Impaction grafting and long-stem cemented ϐixation ∑ Custom internal proximal femur replacement with wraparound of the proximal femur bone over the proximal stem ∑ Proximal femur replacement ∑ Massive proximal femur allograft replacement–prosthesis composite Anatomical restoration of the proximal femur bone stock using a modular, long, ϐluted, cementless femoral stem with distal ϐixation and wrap-around of the proximal femur bone augmented by allograft struts is often the preferred option in the majority of these fractures since they allow restoration of the proximal femur bone stock as well as early weight-bearing. The modular, long, ϐluted stems (Fig. 9.9) rely on adequate initial distal ϐixation for stability and therefore are only possible if the distal extent of the bone loss is proximal to the femur isthmus. When the bone loss is distal to the isthmus, options such as impaction grafting with long, cemented stem ϐixation, custom internal proximal femur replacement with wrap-around of the proximal femur and proximal femur replacement using a ‘tumour-like’ prosthesis should be considered.

Surgical Management of Periprosthetic Acetabular Fractures

Proximal femur replacement (mega-prosthesis) and early weight-bearing might be the choice in elderly patients with limited functional demands, especially when the bone loss extends distal to the femur isthmus. The main disadvantage of proximal femur replacement is a higher rate of dislocation, and therefore a constrained acetabular articulation should be used [21]. The main reason for a higher rate of instability and dislocation is a lack of abductors. If abductors can be saved with a fragment of the greater trochanter, they can be reattached back to the prosthesis of the proximal femoral replacement. It is also preferable to retain the proximal femoral metaphysical bone to increase bone stock, optimise soft-tissue healing and minimise dead space volumes. Patients who have undergone proximal femur replacement have improved quality of life [21].

Figure 9.9 B3 fracture: The stem was revised at our centre using a long, ƚĂƉĞƌĞĚ͕ ŇƵƚĞĚ ƌĞǀŝƐŝŽŶ ƐƚĞŵ ǁŝƚŚ ĚŝƐƚĂů ĨŝdžĂƚŝŽŶ͘ dŚĞ ƉƌŽdžŝŵĂů ĨĞŵŽƌĂů ďŽŶĞ was wrapped around the shaft using cerclage cables. Courtesy of Shibu Krishnan.

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Periprosthetic Fractures of the Hip Joint

Impaction allograft and long-stem cemented femoral reconstruction has been shown to produce satisfactory outcomes in speciϐic centres and is an option especially when the bone loss extends beyond the isthmus. The advantage of impaction bone grafting is restoration of bone stock, particularly in younger patients. The complications include intra- and post-operative fracture and subsidence [21]. Massive allograft–prosthesis constructs have shown satisfactory outcomes in mid- to long-term follow-ups in many series (Figs. 9.10– 9.12); however, their main disadvantages remain a higher rate of nonunion at the graft–host junction as well as at the attachment site of the greater trochanter, resorption of allograft bone, non-availability of massive allografts and potential risk of disease transmission [22]. C fractures: Internal ϐixation without leaving a bridge of native bone, which could act as an area of stress raiser and potential fracture, between the ϐixation device and the tip of the femoral stem is the treatment of choice for most cases. A hybrid locking screw-cable plate with unicortical screws and cables for proximal ϐixation and bicortical locking screws for distal ϐixation is the implant of choice. An allograft strut positioned medially or anteriorly would augment the stability of the construct and union rates. Long oblique or transverse fractures are length-stable and can be surgically treated by a bridge plate construct. Short oblique and transverse fractures have higher strain and are rotationally unstable. It is advisable to span the length of the femur with at least four bicortical screws distal to the fracture and a combination of bicortical screws, unicortical screws and cables proximally to avoid stress raisers [23]. D fractures: It is important to assess the location of the fracture, stability of the femoral prosthesis and the quality of bone stock for each arthroplasty independently. If both the femoral implants are stable the fracture should be surgically managed by open reduction and internal ϐixation. E fractures: In hip replacement, these involve fractures of the acetabulum and femur. Subtype analysis should be done focusing on implant stability, fracture location and bone quality. This should follow a logical treatment plan for each type of the fracture.

Surgical Management of Periprosthetic Acetabular Fractures

9.6.2 Post-operative Management The main aim of treatment of periprosthetic fractures is to achieve stable ϐixation of the fracture with a stable implant to be able to mobilise the patient as early as possible. The post-operative regimen should be individualised to achieve this. The variables to consider are stability of fracture ϐixation and that of the overall construct, and also the patient’s characteristics should be borne before allowing full weight-bearing. Serial radiographs and clinical evaluation will guide in progressive weight-bearing.

9.6.3 Complications Periprosthetic fractures are associated with higher complication rates and re-operation rates [3, 24]. The complications are attributed to the complexity of fractures in a compromised host. The complications include failure of ϐixation, non-union, dislocation, infection, aseptic loosening and higher mortality rate. It is important to differentiate B1 and B2 fractures pre-operatively. If in doubt intraoperative stability testing should be done. Failure to identify a loose stem can result in poor outcomes.

9.6.4 Prevention The incidence of intra-operative fractures can be reduced by preoperative templating, which will allow us to anticipate any intraoperative problems. Adequate exposure of the hip and soft-tissue release should be done if a difϐicult hip dislocation is anticipated. Excessive force should be avoided when reamers, rasps or placement of deϐinitive implants. The incidence of femoral perforation during revision surgery is higher. This can be prevented by adequate visualisation of the proximal femur and use of a guide wire. Intraoperative ϐluoroscopy should be used if one suspects intra-operative cortical perforation.

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HA COLLAR

120mm Ø15 BORE FOR CEMENTOVER STEM 256 PROSTHESIS MADE 10mm LONGER THAN RESECTED BONE

100

246 STANDARD SMILES ROTATING HINGED KNEE OPTION OF 5, 10mm PLATEAU PLATES

CEMENTED TIBIAL COMPONENT

140

Figure 9.10 (a) Image of a D fracture femur (between hip and knee prosthesis) in an 87-year-old lady with a failed attempt at osteosynthesis. The authors managed this by revising the total knee to custom a silver-coated distal femur prosthesis, which was docked to the femur stem using a cement-over construct. (b) Pre-operative design for the custom distal femur replacement prosthesis. Courtesy of Shibu Krishnan.

9.7 Current Controversies and Future Considerations More research should be focused on preventative measures and aim to reduce the incidence of periprosthetic fractures: ∑ Newer stem designs to avoid stress shielding

Current Controversies and Future Considerations

∑ Improved inventory to remove bone cement as well as uncemented and broken stems

Figure 9.11 Intra-operative photograph comparing the dimensions of a resected distal femur and a custom prosthesis. Courtesy of Shibu Krishnan.

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(a)

(b)

Figure 9.12 (a) Intra-operative photograph of docking of the ‘cement-over design’ of the distal femur custom prosthesis to the distal portion of the retained femoral stem. (b) Final photograph after implantation of the above custom distal femur prosthesis. Courtesy of Shibu Krishnan.

References 1. Meek RMD, 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; doi:10.1302/0301-620X.93B1.25087.

References

2. Abdel MP, Houdek MT, Watts CD, Lewallen DG, Berry DJ. Epidemiology of periprosthetic femoral fractures in 5417 revision total hip arthroplasties: a 40-year experience. Bone Joint J, 2016; 98B(4):468– 474; doi:10.1302/0301-620X.98B4.37203. 3. Bhattacharyya T. Mortality after periprosthetic fracture of the femur. J Bone Joint Surg, 2007; 89(12):2658; doi:10.2106/JBJS.F.01538. 4. Blizzard DJ, Klement MR, Penrose CT, Sheets CZ, Bolognesi MP, Seyler TM. Cervical myelopathy doubles the rate of dislocation and fracture after total hip arthroplasty. J Arthroplasty, 2016; 31(9):242–247; doi:10.1016/j.arth.2016.05.070. 5. Berend KR, Mirza AJ, Morris MJ, Lombardi AVJ. Risk of periprosthetic fractures with direct anterior primary total hip arthroplasty. J Arthroplasty, 2016; 31(10):2295–2298; doi:10.1016/j. arth.2016.03.007. 6. Miettinen SSA, et al. Risk factors for intraoperative calcar fracture in cementless total hip arthroplasty. Acta Orthop, 2016; 87(2):113–119; doi:10.3109/17453674.2015.1112712. 7. Duncan CP, Masri BA. Fractures of the femur after hip replacement. Instr Course Lect, 1995; 44:293–304. 8. Duncan CP, Haddad FS. The Uniϐied Classiϐication System (UCS): improving our understanding of periprosthetic fractures. Bone Joint J, 2014; 96B(6):713–716; doi:10.1302/0301-620X.96B6.34040. 9. Lindahl H, Malchau H, Odén A, Garellick G, Surgeon O. Risk factors for failure after treatment of a periprosthetic fracture of the femur. J Bone Joint Surg Br, 2006; 88:26–30; doi:10.1302/0301-620X.88B1. 10. Larson JE, Chao EY, Fitzgerald RH. Bypassing femoral cortical defects with cemented intramedullary stems. J Orthop Res, 1991; 9(3):414– 421; doi:10.1002/jor.1100090314. 11. Hart WJ, Rees RJ, Metcalfe J, Spencer-Jones R. The use of cortical strut allografts for periprosthetic fractures of the femur. Orthop Proc, 2004; 86B:74; doi:10.1302/0301-620X.86BSUPP_I.0860074c. 12. Masri BA, Meek RMD, Duncan CP. Periprosthetic fractures evaluation and treatment. Clin Orthop Relat Res, 2004; (420):80–95; doi:10.1097/00003086-200403000-00012. 13. Pritchett JW. Fracture of the greater trochanter after hip replacement. Clin Orthop Relat Res, 2001; 390, [Online]. Available from: https:// journals.lww.com/clinorthop/Fulltext/2001/09000/Fracture_of_the_ Greater_Trochanter_After_Hip.25.aspx.

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14. Zdero R, Walker R, Waddell JP, Schemitsch EH. Biomechanical evaluation of periprosthetic femoral fracture ϐixation. J Bone Joint Surg Am, 2008; 90(5):1068–1077; doi:10.2106/JBJS.F.01561. 15. Khashan M, Amar E, Drexler M, Chechik O, Cohen Z, Steinberg EL. Superior outcome of strut allograft-augmented plate ϐixation for the treatment of periprosthetic fractures around a stable femoral stem. Injury, 2013; 44(11):1556–1560; doi:https://doi.org/10.1016/j. injury.2013.04.025. 16. Haddad FS, Duncan CP. Cortical onlay allograft struts in the treatment of periprosthetic femoral fractures. Instr Course Lect, 2003; 52:291– 300. 17. Ricci WM, Bolhofner BR, Loftus T, Cox C, Mitchell S, Borrelli JJ. Indirect reduction and plate ϐixation, without grafting, for periprosthetic femoral shaft fractures about a stable intramedullary implant. Surgical technique. J Bone Joint Surg Am, 2006; 88(Suppl 1):275–282; doi:10.2106/JBJS.F.00327. 18. Neumann D, Thaler C, Dorn U. Management of Vancouver B2 and B3 femoral periprosthetic fractures using a modular cementless stem without allografting. Int Orthop, 2012; 36(5):1045–1050; doi:10.1007/s00264-011-1371-y. 19. Fleischman AN, Chen AF. Periprosthetic fractures around the femoral stem: overcoming challenges and avoiding pitfalls. Ann Transl Med, 2015; 3(16):234; doi:10.3978/j.issn.2305-5839.2015.09.32. 20. Tower SS, Beals RK. Fractures of the femur after hip replacement: the Oregon experience. Orthop Clin North Am, 1999; 30(2):235–247; doi:10.1016/s0030-5898(05)70078-x. 21. Al-Taki MM, Masri BA, Duncan CP, Garbuz DS. Quality of life following proximal femoral replacement using a modular system in revision THA. Clin Orthop Relat Res, 2011; 469(2):470–475; doi:10.1007/ s11999-010-1522-2. 22. Yasen AT, Haddad FS. Periprosthetic fractures. Bone Joint J, 2014; 96B(11 Suppl A):48–55; doi:10.1302/0301-620X.96B11.34300. 23. Corten K, Vanrykel F, Bellemans J, Frederix PR, Simon J-P, Broos PLO. An algorithm for the surgical treatment of periprosthetic fractures of the femur around a well-ϐixed femoral component. J Bone Joint Surg Br, 2009; 91B(11):1424–1430; doi:10.1302/0301-620X.91B11.22292. 24. Zuurmond RG, van Wijhe W, van Raay JJAM, Bulstra SK. High incidence of complications and poor clinical outcome in the operative treatment of periprosthetic femoral fractures: an analysis of 71 cases. Injury, 2010; 41(6):629–633; doi:10.1016/j.injury.2010.01.102.

Chapter 10

Periprosthetic Osteolysis after Total Hip Replacement

Pranab Sinha and Shalin Shaunak Rowley Bristow Unit, Ashford and St. Peter’s Hospitals,

NHS Foundation Trust, Guildford Rd., Lyne, Chertsey, KT16 0PZ, UK

[email protected], [email protected]

10.1

Introduction

Hip and knee arthroplasty is amongst the most successful surgical procedures aiming to provide pain relief and restoring function [1]. There are roughly over 600,000 hip and knee arthroplasties carried out in the United States and up to a 2 million hip and knee arthroplasties carried out in the United Kingdom since the creation of their National Joint Registry [2, 3]. The active biological process initiated in response to wear debris which eventually leads to macrophage activation and subsequent insidous progressive bone reabsorption of a previously wellfunctioning total hip replacement (THR) is known as periprosthetic osteolysis [4, 5]. It is a serious complication usually affecting a patient

The Hip Joint Edited by K. Mohan Iyer

Copyright © 2022 Jenny Stanford Publishing Pte. Ltd.

ISBN 978-981-4877-51-0 (Hardcover), 978-1-003-16546-0 (eBook)

www.jennystanford.com

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with THR in the medium and long term. Though initially it can be asymptomatic, it can eventually progress to prosthesis loosening and periprosthetic fracture. These complications can cause the patient signiϐicant morbidity and require complex revision surgery to address them [5].

10.2 Periprosthetic Osteolysis: Current Concepts An active biological cascade is induced secondary to wear debris, metastic cancer or primary neplastic processes, leading to osteolysis [6, 7]. The commonest cause is wear debris. It is a direct response to stimulation of macrophages by biologically active particles, leading to a cell-mediated biological process which leads to bone loss [8].

10.2.1 Initiation of Osteolysis Willert and Semlitsch ϐirst hypothesised in 1977 that mechanical cyclic loading of a hip arthroplasty leads to particulate wear debris arising from the articulating surfaces [9]. Early hip arthroplasty used cement to ϐix the prostheses, and subsequent revisions showed areas of bone loss associated with large granulomas containing particles of polymethylmethacrylate (PMMA) [9]. It was assumed incorrectly that osteolysis was initiated due to cement and was labelled ‘cement disease’ [10]. Current evidence shows that particles of ultrahigh-molecularweight polyethylene (UHMWPE), PMMA, titanium alloys, aluminium oxide, cobalt-chrome and zirconium dioxide can all act as biologically active wear debris and can initiate osteolysis [8]. The size of the wear particulate rather than the type likely has a greater effect on biological activity. Most polyethylene wear particles are less than 1 μm, and initial studies which used light microscopy did not appreciate the number and volume of wear particles which were generated [8]. Subsequent studies examining the tissues with density gradient centrifuging and electron microscopy were able to estimate the number and volume of wear particles more accurately

Periprosthetic Osteolysis

[11]. They also showed that a variety of proteolytic enzymes were found in these periprosthetic tissue and they likely contributed to local tissue distruction [12]. In vitro experiments carried out when the supposition that osteolysis was only the direct result of ‘cement disease’ showed that PMMA particles less than 7 μm would result in phagocytosis via macrophages and the release of tumour necrosis factor alpha (TNFȽ) [13]. Further experiments conϐirmed that all types of bearing surfaces invoked these cell-mediated responses [14]. However, some wear debris are more cytotoxic than others [15]. Kubo et al showed that polyethylene particles of 11 μm than larger controls demonstrated higher levels of cell-mediated responses [16]. Contrary to the original belief, 90% of particles are considered to be small (50% loss of the acetabulum, involving mostly the medial wall but the columns are intact, then this type of defect is considered type II because of the availability of the columns for reconstruction) ∑ Type V: Acetabular defect with uncontained loss of bone stock in association with pelvic discontinuity

12.2.3

Reliability

Inter-observer reliability testing by Gozzard et al. revealed Ɉ values of 0.89 for the acetabulum. The average validation value was Ɉ = 0.86 for the acetabulum [2]. To put things into perspective, clinical epidemiologists consider correlation values of 0.6–0.8 to be ‘substantial’ and between 0.8 and 1.0 to be ‘perfect association’.

Paprosky Classification of Femoral Bone Deficiencies

12.3

Hodgkinson Classification of Radiographic Demarcation of the Socket, Following Total Hip Arthroplasty

12.3.1

Introduction

This classiϐication was proposed by Hodgkinson et al. from Wrightington, UK, in 1988. They reviewed 200 patients undergoing revision arthroplasty and found out a strong correlation between the extent of radiographic demarcation at the bone–cement interface and intra-operative loosening of cemented acetabular components [4].

12.3.2

Classification

The Hodgkinson classiϐication of radiographic demarcation of the socket is as follows: ∑ ∑ ∑ ∑ ∑

Type 0: No demarcation Type 1: Demarcation of the outer one-third Type 2: Demarcation of outer and middle thirds Type 3: Complete demarcation Type 4: Socket migration

12.3.3

Clinic al Significance

This classiϐication helps surgeons decide between partial or complete revision pre-operatively.

12.4 Paprosky Classification of Femoral Bone Deficiencies 12.4.1

Introduction

This classiϐication was described by Paprosky et al. (IL, USA). They emphasised that the classiϐication will help surgeons determine the most appropriate option for reconstruction and thereby assist with ensuring that appropriate implants and instruments are available at

257

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the time of surgery [5]. Gozzard et al. [2] found moderate agreement between the pre-operative and intra-operative validity, but the reliability of the classiϐication was found to be fair (Fig. 12.3).

Figure 12.3

12.4.2

Paprosky classification.

Classification

The Paprosky classiϐication of femoral bone deϐiciencies is as follows: ∑ Type 1: Minimal metaphyseal and diaphyseal bone loss ∑ Type 2B: Anteroloateral metaphyseal bone loss with absent calcar ∑ Type 2C: Posteromedial metaphyseal bone loss ∑ Type 3A: 2A plus diaphyseal bone loss but at least 4 cm of diphyseal support possible ∑ Type 3B: 2B plus diaphyseal bone loss with less than 4 cm of diaphyseal support available ∑ Type 3C: 2C plus complete diaphyseal bone loss

12.4.3

Clinical Applications

∑ Type 1: A cemented or proximally porous, coated cementless implant can be used. ∑ Types 2A, 2B and 2C: An extensively porous, coated cementless stem is preferred. The cemented stem should be avoided because of loss of metaphyseal endosteal bone. ∑ Type 3A: Extensively porous, coated stems or modular distalϐitting tapered stems can be used.

AAOS Classification of Femoral Bone Deficiencies for Revision Hip Arthroplasty

∑ Type 3B: Modular, tapered cementless stems are used in the case of adequate bone stock. Impaction bone grafting is also an option. ∑ Type 4: Impaction bone grafting with a tapered cemented stem is used if the cortex is intact. A composite prosthesis allograft is used if there is no proximal cortex. A long cemented stem is an option in the elderly.

12.5 AAOS Classification of Femoral Bone Deficiencies for Revision Hip Arthroplasty 12.5.1

troduction In

This classiϐication was ϐirst proposed by D’Antonio et al. (PA, USA) in 1989 and later adopted by the American Academy of Orthopedic Surgeons (AAOS) (Fig. 12.4) [6].

Figure 12.4

12.5.2

AAOS classification.

Classif ication

The AAOS classiϐication of femoral bone deϐiciencies is as follows: ∑ Type I: Segmental deϐiciencies o 1a: Proximal, either partial or complete o 1b: Intercalary o 1c: Greater trochanteric

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∑ ∑ ∑ ∑

Type III: Combined Type IV: Rotational or angular mal-alignment Type V: Femoral stenosis Type VI: Femoral discontinuity

12.5.3

Clinical Applications

This classiϐication is very useful in describing bone defects accurately but has less role in guiding the surgeon in determining a reconstructive option.

12.5.4

Reliability

Gozzard et al., in their study, observed inter-observer agreement among consultants and registrars. They noted a fair agreement (Ɉ = 0.28) among consultants and poor agreement (Ɉ = –1.0) among the registrars.

12.6 Saleh Classification of Femoral Bone Deficiencies This system of classiϐication was proposed by Saleh et al. in 1999 (Table 12.1). The study included 21 expert arthroplasty surgeons and was proposed on the basis of estimation of anticipated bone stock following implant removal [3]. Table 12.1 System of classification proposed by Saleh et al. (1999) Type

Defect Treatment

I

No signiϐicant loss of bone stock

Conventional cemented Uncemented components

II

Contained loss of bone stock, cortical sleeve intact

Proximal ϐixation Impaction grafting Porous, coated implant Modular implant

Dossick and Dorr Classification of Proximal Femoral Geometry

Type

Defect Treatment

III

Non-circumferential loss of bone Cortical strut allograft Calcar replacing prosthesis stock uncontained Proximal circumferential loss of bone stock less than 5 cm in length

IV

Circumferential loss of bone stock more than 5 cm in length (distal to lesser trochanter)

Custom implant, proximal femoral allograft

V

Periprosthetic fracture with proximal circumferential loss of bone stock

Restoration of bone stock plus long stem femoral component custom implant proximal femoral allograft.

In the study by Saleh et al., they noted an inter-observer reliability of 0.88 and average validity of 0.88, indicating perfect association. The classiϐication also provides probable treatment options for each type.

12.7 Dossick and Dorr Classification of Proximal Femoral Geometry 12.7.1

I ntroduction

On the basis of the calcar-to-canal ratio, which is deϐined as the diameter of the femur at the midportion of the lesser trochanter divided by the diameter at a point 10 cm distal [7].

12.7.2

C lassification

The Dossick and Dorr classiϐication (Fig. 12.5) of proximal femoral geometry is as follows: ∑ Type A: Calcar-to-canal ratio < 0.5. No thinning of cortices on AP or lateral radiographs. ∑ Type B: Calcar-to-canal ratio 0.5 to 0.75. Thinning of the posterior cortex on the lateral view. ∑ Type C: Calcar-to-canal ratio > 0.75. Thinning of cortices on both views (stovepipe femur).

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Figure 12.5

12.7.3

Dossick and Dorr classification.

Clinic al Significance

Type A is suitable for a cementless femoral stem, type C requires the use of a cemented stem and type B is intermediate.

12.8 Vancouver Classification of Intra-operative Periprosthetic Femur Fractures around Total Hip Arthroplasty 12.8.1

Classification

The Vancouver classiϐication of intra-operative periprosthetic femur fractures [8] (Fig. 12.6) is as follows: ∑ Type A: Proximal metaphyseal o A1: Cortical perforation o A2: Undisplaced linear crack o A3: Displaced or unstable fractures ∑ Type B: Proximal diaphyseal o B1: Cortical perforation o B2: Undisplaced linear crack o B3: Displaced or unstable fractures ∑ Type C: Distal diaphyseal fractures o C1: Cortical perforation o C2: Undisplaced linear crack o C3: Displaced or unstable fracture

Intra-operative Vancouver classification.

263

Figure 12.6

Vancouver Classification of Intra-operative Periprosthetic Femur Fractures

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Classifications Used in Total Hip Arthroplasty

12.8.2

Clinical Applications

∑ Type A1: Bone graft alone ∑ Type A2: Cerclage wire if using proximally a porous, coated stem; can be ignored if using a fully porous, coated stem and there is no distal extension into the diaphysis ∑ Type A3: Needs ϐixation ∑ Type B1: Bypassing stem +/– cortical allograft ϐixation ∑ Type B2: Cerclage wire +/– cortical allograft ϐixation ∑ Type B3: Long stem with cortical allograft ϐixation ∑ Type C1: Morselised bone graft +/– bypass stem and cortical allograft ∑ Type C2: Cerclage wire +/– bypass stem and cortical allograft ∑ Type C3: ORIF

12.9 Vancouver Classification of Post-operative Periprosthetic Femur Fractures around Total Hip Arthroplasty 12.9.1

Classification

The Vancouver classiϐication of post-operative periprosthetic femur fractures (Fig. 12.7) is as follows: ∑ Type A: Peritrochanteric o AG: Greater trochanter o AL: Lesser trochanter

Figure 12.7

Post-operative Vancouver classification.

Tsukayama Classification of Infected Hip Joint Prostheses

∑ Type B: Around or just distal to the tip of the stem o B1: Well-ϐixed femoral component o B2: Loose femoral component o B3: Loose femoral component and poor bone stock ∑ Type C: Well distal to the stem

12.9.2

Clinical Applications

This classiϐication guides the surgeon with treatment decisions. ∑ ∑ ∑ ∑ ∑

AG and AL: Usually stable and can be treated non-operatively B1: ORIF, if displaced B2: Revision to the long stem B3: Revision with struct grafting C: ORIF

12.9.3

Reliability

A European validation for this classiϐication was performed by Rayan et al. The study included consultants, trainees and medical students. It was noted to have an inter-observer reliability of substantial agreement among consultants (Ɉ = 0.72–0.74), orthopaedic trainees (Ɉ = 0.68–0.70) and medical students (Ɉ = 0.61). The validity within B-type fractures revealed an agreement of 77%, with a Ɉ value of 0.67 [9, 10].

12.10 Tsukayama Classification of Infected Hip Joint Prostheses 12.10.1 In troduction Tsukayama et al. proposed this classiϐication on the basis of a study of 97 patients with infected hip joint prostheses [11].

12.10.2 Classif ication The Tsukayama classiϐication of infected hip joint prostheses is as follows:

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Classifications Used in Total Hip Arthroplasty

∑ Positive intra-operative cultures: Two out of ϐive intraoperative specimens were positive on culture in a patient undergoing revision hip arthroplasty with no clinical evidence of infection at the time of revision. ∑ Early post-operative infection: Wound infection developed less than 1 month after the operation. ∑ Late chronic infection: Wound infection developed 1 month or more after the index operation and with an insidious course. ∑ Acute haematogenous infection: This was associated with documented or suspected antecedent bacteraemia and characterised by an acute onset of symptoms in the affected joint with the prosthesis.

12.10.3 Clinic al Applications ∑ Positive intra-operative cultures: Intravenous administration of antibiotics for 6 weeks without operative intervention ∑ Early post-operative infection: Debridement, replacement of the polyethylene inserts of the acetabular component, retention of the prosthesis and intravenous administration of antibiotics for 4 weeks ∑ Late chronic infection: Debridement, removal of all prosthetic components and bone cement, placement of antibiotic beads, intravenous antibiotics for 6 weeks and revision arthroplasty 2 weeks after cessation of antibiotic therapy ∑ Acute haematogenous infection: Debridement, replacement of the polyethylene insert, retention of the prosthesis if it was not loose and intravenous administration of antibiotics for 6 weeks [11]

12.11 Brooker’s Classification of Heterotopic Ossification 12.11.1 In troduction This system was proposed by Brooker et al. from Johns Hopkins Hospital in 1973 on a series of 100 consecutive patients undergoing

Brooker’s Classification of Heterotopic Ossification

total hip arthroplasty (Fig. 12.8). Since then it has been in widespread use and has stood the test of time [12].

Figure 12.8

Brooker’s classification of hetretopic ossification.

12.11.2 Classification Brooker’s classiϐication of heterotopic ossiϐication is as follows: ∑ ∑ ∑ ∑

Class I: Isolated islands of bone Class II: Gap between bones at least 1 cm Class III: Gap between bones less than 1 cm Class IV: Apparent ankylosis

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Classifications Used in Total Hip Arthroplasty

12.11.3 Clinical Applications This classiϐication is useful in the follow-up of high-risk patients and in patients with post–heterotopic ossiϐication resection.

12.11.4 Reliability Vasileiadis et al. from Mayo Clinic, in their study, noted a moderate to substantial agreement (Ɉ = 0.49–0.71) in the inter-observer reliability. Grade IV had the best inter-observer reliability [13, 14].

12.12 Barrack Grading of Cementing 12.12.1 I ntroduction This classiϐication was proposed by Barrack et al. on the basis of a review of 50 second-generation cemented femoral stems [15].

12.12.2 C lassification The Barrack grading of cementing is as follows: ∑ Grade A: White-out with complete ϐilling ∑ Grade B: Slight defects at the cement–bone interface ∑ Grade C: Defective cement mantle or radiolucency involving 50% to 99% of the cement–bone interface ∑ Grade D: 100% lucency or failure to cover the tip of the stem

12.12.3 Clinical Applications This classiϐication helps in predicting the survivability of the implant based on the grade of cementing.

12.13 Crowe Classification of Proximal Migration of the Femoral Head in DDH 12.13.1 I ntroduction This classiϐication was proposed by Crowe and Ranawat et al. (New York, USA) in 1979 on the basis of their experience with 31 total

Crowe Classification of Proximal Migration of the Femoral Head in DDH

hip replacements in patients with severe congenital dysplasia or dislocation of the hip. In a normal hip, the femoral head occupies the acetabulum and contributes to 20% of the pelvic height (Fig. 12.9). Hence the classiϐication is based on the extent of superior migration of the femoral head with respect to the normal position of the femoral head or with respect to the pelvic height. Decking et al. and later Yiannakopoulos et al, showed good inter- and intra-observer reliability of this classiϐication [16–18].

Figure 12.9

Crowe classification.

12.13.2 Classification The Crowe classiϐication of proximal migration of the femoral head in DDH is as follows: ∑ Class I: Migration less than 10% of the pelvis or 50% subluxation of the head ∑ Class II: Migration between 10% and 15% of the pelvis or 50% and 75% subluxation of the head ∑ Class III: Migration between 15% and 20% of the pelvis or 75% and 100% subluxation of the head ∑ Class IV: Migration more than 20% of the pelvis or 100% subluxation of the head

12.13.3 Clinical Applications This classiϐication helps the surgeon prepare for structural allografts of the acetabulum as well as femoral-shortening osteotomies. Also, the surgeon can discuss the prognosis with the patient as severe cases need extensive surgery and are at risk of increased neurovascular complications and failure rates.

269

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Classifications Used in Total Hip Arthroplasty

12.13.4 Reliability Yiannakopoulos et al., in their study, evaluated 145 pelvis anteroposterior (AP) radiographs to determine the reliability of the Crowe classiϐication. They noted an almost perfect association among the observers, with Ɉ values ranging from 0.85 to 0.93.

12.14 Hartofilakidis Classification of Hip Dysplasia 12.14.1 I ntroduction Hartoϐilakidis (Athens, Greece) described three types of congenital dysplasia in his report in 1988 on 42 hips undergoing cemented lowfriction Charnley total hip arthroplasty [19]. Decking et al. showed good inter- and intra-observer reliability of this classiϐication (Fig. 12.10).

Figure 12.10

Hartofilakidis classification of hip dysplasia.

12.14.2 C lassification The Hartoϐilakidis classiϐication of hip dysplasia is as follows: ∑ Dysplasia: Femoral head subluxed but still contained in the true acetabulum ∑ Low or subtotal dislocation: Femoral head subluxed and articulating with the false acetabulum but some overlap of head with the true acetabulum

References

∑ High to total dislocation: Complete subluxation of the femoral head, with a dyplastic and empty true acetabulum

12.14.3 Clinical Applications The authors emphasised the importance of being aware of the false acetabulum pre-operatively and identifying the true acetabulum intra-operatively in order to avoid hip centres and extreme positions and to achieve good outcomes.

12.14.4 Reliability Yiannakopoulos et al. [18], in their study, evaluated 145 pelvis AP radiographs to determine the reliability of Hartoϐilakidis classiϐication. It was noted to have a substantial to almost perfect association among the observers, with a Ɉ value ranging from 0.75 to 0.84.

References 1. Paprosky WG, Perona PG, Lawrence JM. Acetabular defect classiϐication and surgical reconstruction in revision arthroplasty. A 6-year followup evaluation. J Arthroplasty, 1994; 9(1):33–44. 2. Gozzard C, Blom A, Taylor A, Smith E, Learmonth I. A comparison of the reliability and validity of bone stock loss classiϐication systems used for revision hip surgery. J Arthroplasty, 2003; 18(5):638–642. 3. Saleh KJ, Holtzman J, Gafni A, Saleh L, Jaroszynski G, Wong P, Woodgate I, Davis A, Gross AE. Development, test reliability and validation of a classiϐication for revision hip arthroplasty. J Orthop Res, 2001; 19(1):50–56. 4. Hodgkinson JP, Shelley P, Wroblewski BM. The correlation between the roentgenographic appearance and operative ϐindings at the bonecement junction of the socket in Charnley low friction arthroplasties. Clin Orthop Relat Res, 1988; (228):105–109. 5. Valle CJ, Paprosky WG. Classiϐication and an algorithmic approach to the reconstruction of femoral deϐiciency in revision total hip arthroplasty. J Bone Joint Surg Am, 2003; 85A(Suppl 4):1–6.

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6. D’Antonio J, McCarthy JC, Bargar WL, Borden LS, Cappelo WN, Collis DK. Steinberg ME, Wedge JH, Classiϐication of femoral abnormalities in total hip arthroplasty. Clin Orthop Relat Res, 1993; (296):133–139. 7. Dossick PH, Dorr LD, Gruen T, et al. Techniques for preoperative planning and postoperative evaluation of noncemented hip arthroplasty. Techniques Orthop, 1991. 8. Greidanus NV, Mitchell PA, Masri BA, Garbuz DS, Duncan CP. Principles of management and results of treating the fractured femur during and after total hip arthroplasty. Instr Course Lect, 2003; 52:309–322. 9. Brady OH, Garbuz DS, Masri BA, Duncan CP. The reliability and validity of the Vancouver classiϐication of femoral fractures after hip replacement. J Arthroplasty, 2000; 15(1):59–62. 10. Rayan F, Dodd M, Haddad FS. European validation of the Vancouver classiϐication of periprosthetic proximal femoral fractures. J Bone Joint Surg Br, 2008; 90(12):1576–1579. 11. Tsukayama DT, Estrada R, Gustilo RB. Infection after total hip arthroplasty. A study of one hundred and six infections. J Bone Joint Surg Am, 1996; 78:512–523. 12. Brooker AF, Bowerman JW, Robinson RA, Riley LH Jr. Ectopic ossiϐication following total hip replacement. Incidence and a method of classiϐication. J Bone Joint Surg Am, 1973; 55(8):1629–1632. 13. Toom A, Fischer K, Märtson A, Rips L, Haviko T. Inter-observer reliability in the assessment of heterotopic ossiϐication: proposal of a combined classiϐication. Int Orthop, 2005; 29(3):156–159. 14. Vasileiadis GI, Itoigawa Y, Amanatullah DF, Pulido-Sierra L, Crenshaw JR, Huyber C, Taunton MJ, Kaufman KR. Intraobserver reliability and interobserver agreement in radiographic classiϐication of heterotopic ossiϐication, Orthopedics, 2017; 40(1):e54–e58. 15. Barrack RL, Mulroy RD Jr, Harris WH. Improved cementing techniques and femoral component loosening in young patients with hip arthroplasty. A 12-year radiographic review. J Bone Joint Surg Br, 1992; 74(3):38. 16. Crowe JF, Mani VJ, Ranawat CS. Total hip replacement in congenital dislocation and dysplasia of the hip. J Bone Joint Surg Am, 1979; 61(1):15–23. 17. Decking R, Brunner A, Decking J, Puhl W, Günther KP. Reliability of the Crowe and Hartoϐilakidis classiϐications used in the assessment of the adult dysplastic hip. Skeletal Radiol, 2006; 35(5):282–287.

References

18. Yiannakopoulos CK, Chougle A, Eskelinen A, Hodgkinson JP, Hartoϐilakidis G. Inter- and intra-observer variability of the Crowe and Hartoϐilakidis classiϐication systems for congenital hip disease in adults. J Bone Joint Surg Br, 2008; 90(5):579–583. 19. Hartoϐilakidis G, Stamos K, Ioannidis TT. Low friction arthroplasty for old untreated congenital dislocation of the hip. J Bone Joint Surg Br, 1988; 70(2):182–186.

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Chapter 13

Total Hip Arhroplasty

Sharad Goyal,a Chris Booth,a Sarah Sextona and Madhu Raob aDepartment of Trauma & Orthopaedics, St. Richards Hospital,

Chichester PO19 6SE, UK

bWestern Sussex Hospitals Foundation Trust, St. Richard’s Hospital,

Worthing and Southlands Hospitals, Chichester West Sussex, UK

[email protected], [email protected], [email protected], [email protected]

13.1

Introduction

Since 1960, improvements in the technology and manufacturing of prostheses, combined with advances in surgical and anaesthetic techniques, have greatly increased the eơectiveness of total hip arthroplasty (THA). Hip replacement (Fig. 13.1) is one of the most common orthopaedic operations, only recently overtaken by total knee arthroplasty [1]. Patient-recorded outcome measures indicate that hip arthroplasty is arguably one of the most successful medical or surgical interventions available [1–3].

The Hip Joint Edited by K. Mohan Iyer

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Figure 13.1 AP both hips. (Left hip) Hybrid total hip replacement (cemented femoral stem, uncemented acetabulum).

Hip arthroplasty has excellent long-term survivorship (deƤned as time from primary surgery to revision surgery) in all patient cohorts. Cumulative revision for an all cemented implant has been reported at 5.46%, an all uncemented implant at 9.38% and a hybrid implant at 6.14%, 15 years after primary implantation [1].

13.2 Primary Total Hip Arthroplasty 13.2.1

History

Although the earliest recorded hip replacements were carried out by a German surgeon (Gluck, 1891), using ivory to replace femoral heads, innovation and evolution of total joint replacement for relief of pain were continued by Smith-Petersen of the United States in 1925 using glass. The birth of what is considered the modern hip replacement began in the United Kingdom in the early 1960s, with British orthopaedic surgeons Sir John Charnley [4] (cemented

Primary Total Hip Arthroplasty

stem with metal-on-polyethylene bearing surface) and Peter Ring (uncemented implants).

13.2.1.1 Chronology 1936: Cobalt-chrome (Co-Cr) alloy was used. 1938: Robert and Jean Judet (Paris) developed acrylic cement for joint replacement. 1940: Austin Moore (SC, USA) performed the Ƥrst metal hip hemiarthroplasty (Fig. 13.2).

Figure 13.2 Austin Moore performed the first uncemented monoblock hemi­ arthroplasty.

1950s: Frederick Thompson (NY, USA) developed a cemented hemiarthroplasty (Fig. 13.3). 1961: Sir John Charnley (Wrightington) performed cemented hip replacement. 1961: Peter Ring (Redhill) performed uncemented hip replacement. 1981: The Ƥrst use of a hydroxyapatite (HA) coating in orthopaedics was reported at St. Thomas’ Hospital, London [5].

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Figure 13.3 Right cemented Thompson hemiarthroplasty. Left cemented unipolar Exeter hemiarthroplasty.

It is, however, patient satisfaction which is the ultimate key to success; to this end, evolution and innovation continue to drive innovation in implant design and improve survivorship. Uncemented prostheses which allow bone ingrowth have become increasingly popular and have overtaken all cemented implantations as the most common implant choice [1] (Fig. 13.4).

Figure 13.4 Right hip uncemented JRI furlong HA-coated stem. Left hip severe osteoarthritis.

Primary Total Hip Arthroplasty

The hip joint is the second-most common site for primary joint arthroplasty, with over 90,000 arthroplasties performed in the United Kingdom each year [1]. This demand will continue to increase with an ageing population.

13.2.2

Indications

Hip replacement can relieve pain, restore function and improve the quality of life of a patient [6–9]. Most patients who undergo hip replacement are aged between 50 and 80, most commonly within the 70–79 age range. However, each patient is considered as an individual and a joint decision between surgeon and patient reached prior to proceeding with surgery.

Figure 13.5

Right hip osteoarthritis.

Common indications for joint replacement: ∑ ∑ ∑ ∑ ∑ ∑

Osteoarthritis (main indication) (Fig. 13.5) Rheumatoid arthritis Sero-negative inϐlammatory arthropathy Systemic lupus erythematosus (SLE) Ankylosing spondylitis Avascular necrosis (Fig. 13.6)

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Figure 13.6

Right hip: Avascular necrosis of the femoral head.

∑ Developmental dysplasia of the hip (DDH) ∑ Post-traumatic arthritis: after native hip dislocation or acetabular fracture ∑ Acute trauma: displaced intracapsular fracture of the neck of the femur (Fig. 13.7), when clinically indicated instead of hemiarthroplasty ∑ Conversion of an arthrodesed joint (arthrodesis: a surgically induced fusion of the joint)

Figure 13.7

Left hip: Displaced intracapsular fracture of the neck of the femur.

Primary Total Hip Arthroplasty

13.2.3

Symptoms of Hip Pathology

Pain is the most common symptom in a diseased or arthritic joint. The pain is exacerbated by weight-bearing but can be present at rest or cause night-waking. A pain score (0–10) is frequently used as an indicator for assessing the need for operation. Early morning stiơness is also commonly seen in osteoarthritis. Referred pain from the hip can be felt in the knee joint due to a common nerve supply (femoral nerve). Spinal pathology is another common site for referred pain to the hip. Therefore, it is important to examine both the spine and the knee prior to proceeding with hip arthroplasty. The patient can also present with the following symptoms: ∑ ∑ ∑ ∑ ∑ ∑

Joint stiơness and restriction of movement Instability or giving way of the limb Swelling of the joint Crepitus or grating sensations Reduced and limited mobility A decrease in independence and reduction in activities of daily living (ADLs), for example, dressing, bathing, personal care and driving

Patient-reported outcome measures (PROMs) such as the Oxford hip score are useful tools for evaluating the severity of symptoms in both the pre-operative and the post-operative setting. This allows comparison of symptom severity and establishment of improvement, as well as providing a standardised measure of comparison between patient groups [10].

13.2.4

Signs of Hip Pathology

∑ limitation of range of movement: Fixed ƪexion (Thomas’s test) ∑ Contractures: Adduction and external rotation contracture ∑ Scars from previous surgery or infection ∑ Wasting of the muscles around the joint ∑ Antalgic or Trendelenburg’s gait ∑ Leg length discrepancy

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∑ Rheumatoid joint: Warm to touch, severe pain, stiffness and swelling around the hip

13.2.5 Radiographic Features of Degenerative Hip Joint Disease ∑ Decreased joint space due to thinning and wear of articular cartilage ∑ Osteophyte formation at the margins of the joint due to wear and changes in the weight bearing axis. ∑ Wolơ ’s law: Bone remodelling in response to mechanical stress ∑ Subchondral sclerosis (hardening) of the bone below the articular cartilage ∑ Peri-articular cyst formation (bone cysts below the articular surface of the joint) There is poor correlation between the severity of radiographic changes and the patient’s perceived pain. Correlation between the clinical history and examination is key, with radiographic evidence of osteoarthritis supporting the decision to proceed to arthroplasty.

13.2.6

Investigations

Routine assessment includes: ∑ Haematological investigations and MRSA screening (preoperative assessment) ∑ Plain X-rays: Pelvis anteroposterior (AP) view, lateral hip view, including templating marker ∑ Magnetic resonance imaging (MRI)/computed tomography (CT)/bone scans: Can be useful investigations in complex primary and revision surgery

13.2.7 T reatment If operative treatment is considered, then further patient assessment is required to establish suitability for surgical intervention:

Primary Total Hip Arthroplasty

∑ Associated medical comorbidities such as diabetes, ischaemic heart disease, hypertension, body mass index over 40 and vascular insufϐiciency ∑ Medications which affect either surgery or anaesthesia (e.g., anticoagulants) ∑ Skin quality (previous scars, chronic oedema, long-term steroid use)

13.2.7.1 Initial management Conservative treatment must always be considered as the Ƥrst line of treatment: ∑ Weight loss is key to both symptomatic control and operative intervention. ∑ Activity modiϐication and workplace adaption (occupational health). ∑ Use of a walking aid: To reduce the joint reaction force, the walking aid must be in the opposite hand; this will also improve balance and reduce the risk of falls.

13.2.7.2 Medical management ∑ Analgesia: Paracetamol, codeine and alternative opiate-based analgesics ∑ Nonsteroidal anti-inϐlammatory drugs (NSAIDs): Ibuprofen, naproxen ∑ Disease-modifying antirheumatic drugs (DMARDs):

Methotrexate, azathioprine, biological immune modulators ∑ Intra-articular steroid injection: Caution, as it can increase the

risk of periprosthetic joint infection

13.2.7.3 Surgical management The aim of THA is to give the patient a pain-free, stable and mobile joint. After a careful assessment and after failed conservative treatment, operative intervention should be considered. Careful exclusion of alternative pathology, such as referred pain from an arthritic knee or a degrative lumbar disc, must be done prior to proceeding with total hip replacement.

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13.2.8

Components of Hip Replacement

Hip replacement has two main components: ∑ Acetabulum: An acetabular component made of either polyethylene or, if a metal-backed shell with a liner for articulation, either polyethylene or ceramic. Metal articular surfaces are now rarely used due to the controversy of metalon-metal bearing surfaces [11–13]. ∑ Femur: A femoral component consisting of a Co-Cr alloy (cemented implants) or titanium with a porous coating for ingrowth of bone (cementless implants). Modern hip systems are modular. They have: ∑ ∑ ∑ ∑

A femoral stem A femoral head (metal or ceramic) An acetabular shell (uncemented acetabular component) An acetabular liner (polyethylene, ceramic)

There are three common techniques available for primary hip replacement: ∑ Cemented: Uses cement in all patients, particularly recommended in those with osteoporosis, to reduce intraoperative fracture risk ∑ Uncemented: Historically used in younger patients but popularity increasing in all age groups ∑ Hybrid: A combination or cemented and uncemented implants, traditionally a uncemented acetabular component with cemented femoral stem

13.2.9

Types of Hip Replacements

13.2.9.1 Cemented joint replacement Bone cement is a polymer of polymethylmethacrylate (PMMA) which acts as a grout between the implant and bone (Fig. 13.8). Use of cemented hip replacement varies around the globe despite excellent long-term survivorship. Cement is used in hip replacement surgery, in 63% of THR operations in Sweden [14], 57% in Norway [15] and 53% of hip replacements in the United Kingdom [1]. This contrasts

Primary Total Hip Arthroplasty

with countries such as Denmark where any cemented implant makes up only 18% of hip arthroplasty [16], and in the United States this ϐigure is even lower at 6% [17]. A study in India [22] compared 140 cases after dividing them equally between cemented and uncemented hip replacement groups. Cemented implants showed better functional outcomes than uncemented in THA at 6 weeks, 3 months and 6 months. Another study from India [23] concluded that cemented implants are cheaper than uncemented implants. Better short-term clinical outcomes mainly improved pain, and early painfree full weight-bearing was obtained from cemented ϐixation.

Figure 13.8

Cemented stem and acetabular cup.

13.2.9.2 Uncemented joint replacement HA, titanium porous coatings or trabecular metal all avoid the need for cement by encouraging osteointegration as bone ingrowth occurs (Fig. 13.9). The primary Ƥxation is an anatomic or press-Ƥt technique, with secondary biological bone ingrowth producing long-term stable Ƥxation. This technique is common in the United States, with 94% of THA cases using uncemented femoral stems in 2018 [17] compared with 40% in the United Kingdom [1].

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Figure 13.9

Right hip: Uncemented stem and acetabular cup.

13.2.9.3 Hybrid replacement A hybrid replacement is where one component is cemented and the other is uncemented (Fig. 13.10). In the United Kingdom 21% of hip replacements are performed as hybrids, predominantly made up of a cemented femoral stem with an uncemented acetabular component [1].

Figure 13.10 Left hybrid hip replacement: Cemented femur and uncemented acetabular cup.

Primary Total Hip Arthroplasty

The decision to perform a hybrid replacement originates from an increased rate of aseptic loosening of cemented acetabular components, while cemented femoral components demonstrate excellent survivorship [18]. Caution should be taken in patients with osteoporosis, and cemented acetabular components should be considered to reduce intra-operative acetabular fracture risk.

13.2.10 Types of Materials Used in Joint Replacement Surgery Figure 13.11 shows various types of prostheses, materials and cements used in joint replacement surgery. ∑ Co-Cr alloy: Cobalt, chrome, nickel, molybdenum, carbon and tungsten. These alloys have excellent strength, biocompatibility and resistance to corrosion. ∑ Stainless steel: Iron, chromium, nickel, molybdenum and carbon. Stainless steel has good biocompatibility, ductility and resistance to corrosion. ∑ Titanium alloy: Titanium, aluminium and vanadium have improved resistance to corrosion compared to stainless steel and are ductile and biocompatible. Titanium is used for uncemented stems as its modulus of elasticity is closer to that of bone than the stiơer Co-Cr alloy which is used in cemented stems. ∑ Ceramics: Compounds of metals and nonmetallic materials such as alumina (aluminium oxide) and zirconia (zirconium oxide). These are biocompatible, hard, brittle compounds with increased wettability (reduced surface tension of a liquid on the solid surface so the liquid spreads over the surface). Squeaking has been noted following ceramic-on-ceramic joint replacements, which adversely affects patient satisfaction. Caution during implantation is required to reduce the risk of ceramic fracture. ∑ Ultrahigh-molecular-weight polyethylene (UHMWPE): A polymer manufactured by direct compression moulding and sterilised by gamma irradiation, promoting cross-linking, which reduces early wear.

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Figure 13.11

Prostheses, materials and cements used in joint replacement surgery.

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o Highly-cross-linked polyethylene (HCLPE): Introduced in 1990 for clinical use with the expectation that it would exhibit less wear. However, increased cross-linking resulted in diminished mechanical properties, leading to failure. Second-generation HCLPE manufacture is now vitamin-E-stabilised with improved mechanical strength. ∑ HA coating: A compound like the inorganic matrix of bone and is osteoconductive. It is used mainly for surface coating of the uncemented implants to encourage a high rate of osteointegration. ∑ Cement: Formed by mixing a liquid (monomer) with a powder (polymer) in an exothermic polymerisation reaction. The liquid contains dimethyl toluidine and hydroquinone, while the powder contains the polymer methyl methacrylate. Additives such as barium (radio-opaque), benzoyl peroxide, chlorophyll (gives a green colour) and heat-stable antibiotics, such as gentamicin, tobramycin or clindamycin, can be added to the powder. o Cementing techniques: ƒ First-generation technique: Insertion of the cement with Ƥnger-packing into the canal. No cement plug was used. ƒ Second-generation technique: Cement plug introduced into the medullary canal of the femur, pulse lavage to clean the femoral canal and a cement gun used to introduce cement in a retrograde fashion. ƒ Third-generation technique: Use of a distal femoral centraliser, vacuum-mixing of the cement and brushand-pulsatile lavage to clean the femoral canal and a cement gun as before. ƒ Fourth-generation technique: Addition to the third generation of a stem centraliser, both proximally and distally. ƒ Aim for a 2 mm cement mantle around all the components to prevent premature loosening and failure. Is the head size important in THR? Since the era of Charnley, the femoral head size has ranged from 22.25 mm to 45 mm or greater. A

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smaller head size produces less volumetric wear but greater linear wear, with an increased risk of dislocation due to less excursion distance. Larger heads have less linear wear, more volumetric wear and lower dislocation rates; however, with less space left for the acetabular liner there is a thinner layer of polyethylene and increased wear rates. With the introduction of newer polyethylene (HCLPE) the trend is towards using larger heads. The head size of 28 mm has optimum wear characteristics, although dislocation risk is still a concern. The trend since 2003 is a progression to 32 mm and 36 mm head sizes in all bearing combinations [1].

13.2.11 Surgical Approaches 13.2.11.1 Direct lateral transgluteal (Hardinge) approach This is an approach through the abductor muscles [19]. This approach requires the detachment of the gluteus medius and minimus, with or without a split in the vastus lateralis. Strong surgical repair is essential to enable early mobilisation and recovery. Advantages: ∑ ∑ ∑ ∑

Lower rate of dislocation Lower rate of sciatic nerve injury Preservation of the posterior soft-tissue envelope Avoidance of the technical diƥculties of trochanteric osteotomy

Disadvantages: ∑ ∑ ∑ ∑ ∑

Potential damage to superior gluteal nerve Damage to abductor muscles, leading to Trendelenburg’s gait Exposure of the proximal acetabulum limited Inability to adjust trochanteric tension Risk of heterotopic ossiƤcation

13.2.11.2 Posterior approach This is an approach that splits the gluteus maximus bluntly in line with its Ƥbres. Short external rotators are released at the insertion site on the posterior greater trochanter. This is the preferred approach for primary arthroplasty.

Primary Total Hip Arthroplasty

Advantages: ∑ ∑ ∑ ∑

Trendelenburg’s gait avoided with abductor preservation Low incidence of heterotopic ossiƤcation More consistent exposure The preferred approach by various surgeons specialising in hip reconstruction and revision surgery

Disadvantages: ∑ Increased risk of dislocation ∑ Increased risk of sciatic nerve injury

13.2.11.3 The Charnley approach The Charnley lateral approach is now predominantly of historic value. The hip is approached via a trochanteric osteotomy, which requires separate ϐixation, leading to increased recovery time and an increased risk of trochanteric non-union.

13.2.11.4 Minimally invasive surgery Minimally invasive surgery allows the surgeon to replace the hip through one or two small incisions. It can be indicated in slim, wellmotivated patients. Advantages: ∑ Smaller incision (cosmetic) ∑ Faster recovery ∑ Reduced post-operative pain Disadvantages: ∑ Requires speciϐic instrumentation ∑ Fluoroscopy required intra-operatively ∑ Increased risk of wound complications

13.2.11.5 Direct anterior approach With the move to tissue-sparing procedures, the direct anterior approach (DAA) is gaining popularity in primary arthroplasty and revision arthroplasty, as well as resurfacing. The patient is positioned supine on a traction table commonly; however, a standard operating table can be used. The incision starts two Ƥngerbreadths, 2–4 cm,

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distal and lateral to the anterior superior iliac spine (ASIS), centred over the greater trochanter. Care is taken of the lateral femoral cutaneous nerve. An incision is made over the muscle belly of the tensor fascia lata. An intramuscular interval is developed between the tensor fascia lata on the lateral side and sartorius on the medial side. The DAA has been documented in much detail in Chapter 8. Advantages: ∑ ∑ ∑ ∑

Less invasive muscle-sparing approach Improved functional outcomes earlier Early recovery and discharge from hospital The only commonly used approach which is both `intermuscular’ and `internervous’

Disadvantages: ∑ Signiϐicant learning curse ∑ High risk of nerve injury (lateral femoral cutaneous and femoral nerves) ∑ Higher intra-operative complication rate ∑ Fluoroscopy maybe required intra-operatively The features of DAA should be shared actively with physio-/ occupational therapists to avoid the necessity for the use of a low chair for sitting purposes and avoid crossing the legs in bed. Table 13.1 Advantages and disadvantages of various surgical approaches Surgical approach

Advantages

Disadvantages

Posterior approach

* Excellent hip exposure * Sparing of abductor muscles

* Increased incidence of dislocation * Risk of sciatic nerve injury

Transgluteal lateral (Hardinge) Approach

* Preservation of posterior capsule – lower dislocation risk * Protection of sciatic nerve

* Abductor weakness (Trendelenburg’s gait) * Limited proximal exposure

Primary Total Hip Arthroplasty

Surgical approach

Advantages

Disadvantages

Direct anterior * Early recovery approach * Reduced dislocation rate (DAA) * Intermuscular approach * Supine positioning * Between intermuscular and internervous panes

* Signiϐicant learning curve * Increased vascular risk * Speciϐic instrumentation required * Fluoroscopy probably required

Minimally invasive approach

* Restricted surgical ϐield * Higher wound complications * Speciϐic instrumentation required * Fluoroscopy probably required

* Minimal soft-tissue injury * Lower blood loss * Early recovery

13.2.12 Complications Intra-operative complications: ∑ ∑ ∑ ∑

Blood loss requiring intra-operative transfusion Periprosthetic fracture (uncemented implants) Fat embolism (cemented implants) Neurovascular damage (sciatic nerve/lateral femoral cutaneous nerve) ∑ Bone cement implantation syndrome (BCIS): Important cause of intra-operative mortality and morbidity in patients undergoing cemented hip arthroplasty. ∑ Leg length discrepancy: Risk can be minimised by preoperative templating. Up to 2cm can be treated with heal riser inserts. This is a common source of medicolegal action. Post-operative complications: ∑ Early: o Periprosthetic joint infection 0.6% to 2.2% [20] o Haematoma o Venous thromboembolism: Pulmonary embolism and deep vein thrombosis (PE/DVT) o Dislocation 2%–3% (Fig. 13.12) o Sciatic and femoral nerve palsy 25 should be advised to seek appropriate guidance to reduce the BMI to a healthy level. Other nonmodiϐiable factors should be considered when considering a patient’s likely outcomes, prognosis and expectations, as well as appropriate surgical versus nonsurgical treatment options.

21.6

Hip Pathologies

21.6.1 Femoro-Acetabular Impingement FAI is deϐined as a pathological mechanical process by which morphological abnormalities of the acetabulum and/or the femur combined with vigorous hip motion can damage the soft-tissue structures within the hip joint itself [19]. For the clinical diagnosis of FAI, the hip should be symptomatic. There are two types of FAI, which

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differ in both the anatomical site of the morphological abnormality and the mechanism by which it causes intra-articular damage [20].

21.6.1.1 Types of FAI-cam and pincer impingement The ϐirst FAI type is ‘cam impingement’, in which the morphological abnormality is located on the femoral side of the hip joint. The cam deformity is extra bone formation at the anterolateral head–neck junction, causing a nonspherical femoral head. During hip motion, particularly ϐlexion and internal rotation, the cam deformity can be forced into the acetabulum, causing shear force at the chondrolabral junction (Fig. 21.3).

Figure 21.3

Types of FAI: pincer and cam.

The second type of FAI is referred to as ‘pincer impingement’ (Fig. 21.2). This refers to a morphological or orientational abnormality of the acetabulum, leading to an overcoverage of the femoral head. This can manifest either as a deep acetabulum or as a retroverted acetabulum, which are most commonly seen anteriorly. Particularly during hip ϐlexion, the femoral neck can impinge against the overcovered acetabulum, causing an impaction on the labrum. This type of impingement might lead to labral and also cartilage damage throughout the acetabulum in a small thin strip around the labrum. Cam deformity and pincer deformity may exist together, and when this leads to symptoms it is referred to as a mixed type of FAI. It is very important to recognise that cam deformity or pincer deformity will not always cause FAI. Susceptibility is highly dependent on many cofactors, including other anatomical characteristics of the hip, such as femoral and acetabular version; on the type and intensity of hip

Hip Pathologies

movement; and on the vulnerability of the labrum and cartilage itself [21].

21.6.1.2 Prevalence of FAI It is important that the clinican understands that the morphology which can lead to FAI is highly prevalent and is in itself not a pathology. The prevalence of cam deformity in the general asymptomatic population has been estimated at around 10%–25%. Cam deformity is more prevalent in males (25%–50%) than in females (0%–10%). Interestingly, the prevalence can be extremely high in male athletes (up to 89%) compared to only 9% in non-athletic controls [22]. Pincer deformities are generally more prevalent in women, but the prevalence varies widely between studies because of the heterogeneity in what is considered pincer deformity. General overcoverage is a condition in which the femoral head is positioned deep in the acetabulum or when there is an overgrowth of the acetabular rim. This type of pincer deformity is present in about 20% of the population. When focal overcoverage or acetabular retroversion is also taken into account, the prevalence can be as high as 60%. Whether the latter should be regarded as pincer deformity is still under debate [23]. It is unknown if pincer deformity is more prevalent among athletes.

21.6.1.3 Aetiology Hip loading during adolescence is emerging as a key factor in the aetiology of cam deformity. Cam deformity was ϐirst recognised by Murray et al. in 1971 [24], and more recently, hip loading during skeletal maturation has appeared to be related to the development of cam deformity. Since 2011, two cohort studies described the development of cam deformity during adolescence [25]. The prevalence was higher in both football players and basketball players than in non-athletic controls. In these young athletes, the extra bone formation in the anterolateral head–neck junction becomes radiographically visible from around the age of 13 years, and the cam deformity develops gradually until the growth plate closes. After growth plate closure, the morphology of the proximal femur appears to change minimally. This is supported by the high prevalence of cam deformity in adult athletes participating in high-

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impact sports, ranging from 60% to 89% [26]. Therefore, cam deformity is most likely a bone adaptation in response to vigorous hip loading when the growth plate is still open. During the time of skeletal maturation, there might be a dose–response relationship between the intensity of sports practice and the development of cam deformity. Genetics might also play a role, as cam deformity might have a familial pattern, with siblings being three times more likely to have cam deformity than controls. The aetiology of pincer deformity is unknown and there are no studies available that investigate how pincer deformity develops.

21.6.1.4 Association with pain and pathology A prerequisite of the FAI deϐinition is the presence of hip pain and symptoms. Without hip pain, the diagnosis of FAI cannot be made. The presence of cam or pincer deformity in isolation has been associated with hip pain in young adults, but only 26% of people with cam deformity complain of hip pain. Asymptomatic young adults with cam deformity have a 4.5 times higher risk of developing hip pain within 4 years than those without cam deformity. However, athletes might have a higher risk of developing hip pain resulting from cam deformity, particularly when they experience repetitive movements of ϐlexion and internal rotation of the hip, as in American football (gridiron) players and ice hockey players. Following the anterolateral location of cam deformity, the anterosuperior region of the acetabulum is mostly affected corresponding to the site where the cam deformity is forced into the acetabulum with ϐlexion and internal rotation. This results locally in high shear forces at the acetabular chondrolabral junction. Resultant damage to the labrum can progress to its detachment from the acetabular rim and involvement of the acetabular cartilage. This can range from slight softening and swelling of the cartilage in the early stage to delamination of the cartilage from the subchondral bone in later stages, a so-called carpet lesion. The size of the cam deformity is positively correlated with more severe cartilage damage [27].

21.6.2 Osteoarthritis Cam deformity is associated with hip OA, whereas the association between pincer deformity and OA is conϐlicting. Since cam deformity

Hip Pathologies

is present immediately after skeletal maturity, prospective studies to evaluate the risk for developing OA would require a long-term followup of decades. Therefore, current cohort studies consist mostly of individuals aged over 40 years. In this population, there is strong evidence that cam deformity is a risk factor for development of OA [28]. A prospective study found that cam deformity conferred a four times higher risk of developing OA within 5 years [29]. Regarding the higher prevalence of cam deformity in athletes and the higher chance to experience FAI in the presence of cam deformity because of the repetitive movements they undertake, athletes might even be more likely to develop OA due to cam-type FAI. The relationship between pincer deformity and OA is less clear. Some studies show a moderately increased risk for having OA in the presence of pincer deformity, while others, including higher-quality studies, showed no association or even a protective effect of pincer deformity on development of OA [30]. The early identiϐication of FAI in athletes with hip and groin pain is essential. Unfortunately there is no gold standard of clinic diagnosis of FAI. Clinical signs which are often reported to indicate the presence of FAI include reduced range of hip internal rotation, particularly when the hip is ϐlexed, and a positive ϐlexion, adduction, internal rotation (FADIR) test. Unfortunately these tests are not speciϐic to detect FAl and may result in a high number of falsepositive results. Therefore radiological examination is required. Plain radiographs can be useful and generally a plain AP view of the pelvis will indicate the presence of FAl when read by an experienced radiologist. Athletes who present with FAl should be encouraged to avoid the position of impingement as much possible. This position of impingement is usually ϐlexion, internal rotation and adduction or any combination of these. This may involve activity modiϐication on a day-to-day basis, as well as during athletic pursuits. For example, in ball sports this may involve playing in a different position which requires less time changing direction and getting down low to the ball. It may also involve reducing the time spent on the ϐield. Maximising dynamic neuromotor control around the hip will also assist in achieving this goal.

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21.6.3

Acetabular Labral Tears

Labral tears are seen frequently in the athletic population, with 22% of athletes with groin pain having labral tears and 55% of patients with mechanical symptoms and hip pain having labral tears [3, 7]. The aetiology of labral tears is well described in the literature. However, studies have also shown that there a high prevalence of labral tears in the asymptomatic population, especially as people age, and as with many other parts of the musculoskeletal system, pain does not always match pathology.

21.6.3.1 Pathology The presence of both cam-type FAl and DDH can increase the risk of a labral tear. Mechanisms include impingement of the labrum in the presence of FAl and increased shear forces on the outer joint margins, including the labrum, in the presence of DDH. In addition, patients with labral tears are 40% more likely to have coexisting chondropathy [32]. The inability of a damaged labrum to adequately sustain chondral nutrition via the synovial ϐluid as well as the reduced load-bearing capacity of a damaged labrum may provide an explanation for these ϐindings. The prevalence of labral tears is greatest anteriorly [33]. Various causes for the high number of anterior labral tears have postulated, including reduced thickness of the labrum anteriorly, the prevalence of FAl lesions seen anteriorly, resulting in anterior impingement, and common functional activities, especially those with repetitive twisting and pivoting of the hip. The reduced bony support seen anteriorly in the hip due to anteverted position of the acetabulum, which results in higher shear force on anterior soft tissue structure, is also a likely cause of labral pathology. It has been shown that in the last 20%–30% of the stance phase of gait, and in more than 5° of hip extension, increased forces are placed on anterior soft tissue structures by the head of femur [34]. Tears of the acetabular labrum are usually classiϐied as type I or type II tears [35]. Type I is described as a detachment of the labrum from the articular hyaline cartilage at the acetabular rim. Type II is described as cleavage tears within the substance of the labrum. The location of these tears relative to the vascularisation of the

Hip Pathologies

labrum inϐluences the potential for healing of the tear and the most appropriate type of intervention. Clinically, the identiϐication of labral tears in patients remains difϐicult. The patient often complains of mechanical symptoms such as locking, clicking, catching and giving way. The location of pain is usually reported to be within the anterior hip or in the anterior region, although some patients report pain in the posterior buttock. The diagnostic accuracy of radiological investigation for labral tears has improved in recent years, with MRI and magnetic resonance arthrography (MRA) (Fig. 21.4), both having a reasonable degree of sensitivity and speciϐicity but not conϐirmed the gold standard to diagnose labral pathology [7].

Figure 21.4

T1 coronal MR image showing a labral tear (arrow).

Athletes with labral pathology may respond to conservative management, and this should always be tried prior to undergoing surgery. Management should be directed to unloading the damaged labrum, which is almost always anterior and/or superior. Repetitive hip ϐlexion, adduction or abduction and rotation at the end of range should be avoided through activity modiϐication. Improving hip joint neuromotor control via activation of the deep stabilising muscles, initially in an unloaded then a progressively loaded manner, appears to assist in the unloading of the labrum.

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Gait retraining may also be undertaken to minimise excessive hip extension at the end of stance phase of gait, as increased hip extension has been demonstrated to increase the loads on anterior hip joint structures. Neuromotor control of the hip should be maximised as outlined before, and any remote factors inϐluencing the mechanics of the hip should be addressed.

21.6.4

Ligamentum Teres Tears

Ligamentum teres tears are commonly reported in athletes undergoing hip arthroscopy and are being reported more frequently in the literature. Studies have found up to 70% of athletes undergoing hip arthroscopy for FAl and labral tears also have tears of the ligamentum teres [3]. Tears of the ligamentum teres are classiϐied as type I, which is a partial tear; type II, which is a complete rupture; and type III, which describes a degenerate ligament [36]. Ligamentum teres tears can occur in isolation but often coexist with FAl, dysplasia and synovitis, probably due to the altered joint loads seen in these conditions. The mechanism of injury for ligamentum teres most commonly involves forced ϐlexion and adduction and often internal or external rotation [36]. Twisting motions and hyper-abduction injuries have been reported to cause a tear to this ligament. With the likelihood of the ligamentum tear playing a large proprioceptive and stabilisation role of the hip becoming increasingly recognised, the prompt diagnosis and management of these injuries in the athletes is essential. Likewise, any surgical procedure which sacriϐices the ligamentum teres through open dislocation should be carefully considered. If suspected, the principal of management are similar to those of labral pathology, with a particular emphasis on regaining neuromotor control, excellent proprioception and avoiding positions that place the ligament under most stress using activity modiϐication.

21.6.5 Synovitis Synovitis is often seen in athletes with other intra-articular hip pathology, whether it is FAl, labral tears, ligamentum teres tears or chondropathy. It is rarely seen as a primary entity. Synovitis can

Hip Pathologies

cause considerable pain in the hip joint, with night pain and pain at rest being common presentation. The implications of synovial dysfunction on cytokine production, nutrition and hydration of articular cartilage, which may already show sign of chondropathy, is signiϐicant for the long-term health of the hip joint. Management should aim to address the other coexisting pathology, restore normal neuromotor control around the help, modify loads as well as introduce anti-inϐlammatory measures such as oral nonsteroidal anti-inϐlammatory drugs (NSAIDs) or intraarticular injections. When synovitis is present, the positions of hip ϐlexion and internal rotation should be avoided to try and optimise movement of synovial ϐluid through the joint.

21.6.6

Chondropathy

Changes to the chondral surfaces of the hip are often seen in conjunction with other hip pathologies. It is reported that the presence of FAI, decreased acetabular anteversion, labral pathology and DDH can increase the risk of chondropathy and ultimately OA of the hip. In patients with signiϐicant labral pathology, chondral loss is often up to 70% of the full thickness or Outerbridge grade III or IV. The presence of chondropathy at arthroscopy is associated with worse patient-reported outcomes, up to 3 years post-operatively, especially compared to healthy controls. In addition, outcomes are unlikely to improve over times [32]. Patients with severe chondral lesions are more likely to have worse outcome than those with mild lesions and have a much higher risk of progressing to total hip replacement within 2 years of an arthroscopic procedure (Fig. 21.5). The majority of chondral lesions are seen on the anterior or superior aspect of the acetabular rim, at the chondrolabral junction. This is not surprising considering that this is also the location for the majority of cam and pincer lesions and the majority of labral tears. Chondropathyis difϐicult to manage and maybe difϐicult to conϐirm in the early stage without arthroscopic conϐirmation. If suspected, the management again is similar to that of labral pathology, as the majority of chondral lesions of the hip occur in the anterior aspect of the acetabular rim at the chondrolabral junction. As such, this region should be unloaded in the same fashion as labral pathology,

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with an emphasis in regaining normal neuromotor control of the hip. As chondropathy is likely represent hip OA in its early stage, aspects of hip OA should be introduced. This may include weight reduction where appropriate, lifestyle factors, general ϐitness programmes. aquatic exercise programmes and speciϐic strengthening exercises for hip muscles and in some cases counselling to modify the amount of weight-bearing activities the athlete undertakes.

Figure 21.5 (a) MR image showing a full-thickness chondral defect. (b) Arthroscopic view of severe chondral damage.

21.6.7

Hip Instability

Hip instability is increasingly being recognised as an important potential source of hip pain. Gross instability of the hip is seen in DDH and generalised hypermobility, while localised directional instability may be present in cam-type FAI (as a contra-coup lesion), ligamentum teres tears (due to reduced proprioception), hips with large amounts of anteversion (as capsular insufϐiciency anteriorly) and in ‘normal’ hips which are subjected to extremes of range of motion, such as in dancers and gymnasts. There is no good clinical or radiographic test for instability, and diagnosis is usually one of clinic suspicion when extremes of range of motion, poor balance, poor control in functional tasks, observable excessive translation of the femoral head and clicking and clunking are present. Treatment for hip instability involves restoring hip muscle strength, improving balance and functional control; modiϐication of functional tasks to avoid extremes of range; and education regarding the risk of repeated activity in unsafe and extremes of range. Some surgeons

Treatment

have reported treating hip instability by arthroscopic shortening of the hip capsule, but outcomes for this procedure are unknown. In extreme cases of DDH and abnormal acetabular version, patients may consider major orthopaedic procedure such as peri-acetabular osteotomy.

21.7 Treatment 21.7.1

Principles of Rehabilitation of the Injured Hip

Due to its role in all activities of daily living, including simple activities such as sit-stand, standing and walking, it is hard to rest the hip. Rehabilitation of the injured hip requires consideration of the interplay between pain and loading (including progression of exercises and activities). It appears the most provocative loading for hip occurs when rotational loads, loading at extremes of range and overload in the impingement position occur, rather than an excessive amount of walking, running or other weight-bearing activities which do not involve extremes of rotation, impingement and other endrange positions. It is vital that the patient and the clinician have a good understanding around monitoring joint loads and the loading response. There is no level I or II evidence which supports the ideal rehabilitation programme or evaluates the effectiveness of particular principles of rehabilitation of the hip. However, the general principles of management of hip pathology are straightforward [37, 38]. In addition, several recent studies have detailed the physical impairment which exists in people with hip pain and pathology, around which an impairment-based rehabilitation guideline can be based. The most commonly reported physical impairments seen in hip pain and pathology are: ∑ Reduced hip joint range, especially ϐlexion and internal rotation ∑ Reduced hip muscle strength in all hip muscles, especially abductors and adductors (men and women), extensors (mostly women) and external rotators (mostly women) [39] ∑ Reduced balance in single-leg dynamic tasks

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∑ Increased femoral adduction in single-leg squats ∑ Reduced trunk muscle strength ∑ Alterations in gait biomechanics (primarily reduced range of hip motions in gait) [40] ∑ Reduced functional performance, especially in hopping and squatting and squatting tasks ∑ Probably adverse loading within the hip due to morphology, changes in range of motion, hip muscle weakness and poor functional performance ∑ Abnormalities of the kinetic chain

21.7.2 Nine Principles of Rehabilitation for Hip Pain Patients 21.7.2.1 Restore the hip range of motion The hip range of motion may impact the load within the hip. Hip ϐlexion and extension may increase load on the anterior and superior regions of the hip [41]. As most FAI lesions and associated hip pathology occur in the anterior and superior region of the hip, loads associated with these regions of hip require consideration. The range of motion may be limited in this group if movement at the end of the range loads damaged tissue in a manner which provokes pain. Often a patient’s range of motion is limited to protect the damaged region of the hip, and as such, gaining a greater range of motion may also worsen symptoms. Manual techniques such as soft-tissue release and needling, stretching and muscle activations may improve range, but should be done with respect to the athlete’s pain during and after treatment.

21.7.2.2 Restore hip muscle strength Restoration of hip muscle strength should follow these principles: ∑ Phase 1: Deep hip stabiliser retraining. The short hipstabilising (SHS) or external rotator muscles are those with the greatest capacity to provide dynamic stabilisation of the hip. Retraining of these deep hip stabilisers may be undertaken in the early stages of rehabilitation. As pain appears to inhibit

Treatment

effective activation of the SHS muscles, pain must be well controlled. The initial step involves educating the patient in the role of the SHS muscles to provide dynamic hip stability and the location and actions of these muscles. The second step involves facilitating independent contraction of these muscles. This is often best commenced in four-point kneeling, where the patient is taught to activate the SHS muscles and then perform an isometric external rotation or adduction contraction against minimal resistance. Progression of the retraining includes providing different levels of resistance, number of repetitions and speed of movements. ∑ Phase 2: Gluteus maximus retraining. The gluteus maximus plays an important role in generating extension, adduction and external rotation torque and has the potential to provide hip stabilisation by resisting anterior hip force. Facilitation of independent gluteus maximus contraction may be best commenced prone, where the patient is taught to perform an isometric external rotation contraction against minimal resistance (low-level tonic hold of these muscles). As with the SHS muscles, feedback may assist in ensuring that the muscle is activated. Since the gluteus maximus is more superϐicial, feedback may be provided by palpation. The activation of the gluteus maximus should be undertaken in a variety of degrees of the hip range of motion as the functional demands of the athlete’s activity require. It should be then progressed from open chain to closed chain and then functional positions. ∑ Phase 3: Generalised strengthening exercises. Generalised hip-strengthening exercises should only be commenced when the patient and clinician are conϐident that the key stabilising muscles can be activated and activation maintained. During this phase, the aim is to restore muscle function (strength, endurance) and proprioception. This phase remains lowimpact. Exercises should initially be undertaken with speciϐic activation of the deep stabilisers prior to completing the

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exercises. This ensures that the athlete has adequate control of the hip prior to placing it under load, which will assist in protecting vulnerable or damaged structures within the hip. Strengthening exercises need to be targeted to the needs of the individual, progressed according to patient responses and targeted to the sporting/physical requirements. For example, an athlete who regularly jumps and lands, such as a netballer or gymnast, should incorporate these actions into his/her rehabilitation programme. Exercises are frequently commenced in the prone (to ensure speciϐicity and isolation of muscle activations) or four-point kneeling position and then progressed into functional/weightbearing positions, bilaterally and then unilaterally. Such exercises also address the rehabilitation goals of balance and functional task performance.

21.7.3 Improve Balance and Proprioception Retraining of balance can commence immediately in lowimpact dynamic functional tasks and progress as symptoms and performance allow. It is important that during balance tasks, the athlete is reminded of correct alignment of the pelvis and femur and maintains activation of the SHS muscles to facilitate control.

21.7.4 Improve Hip Control in Functional Task

Performance

Reducing load on the anterior aspect of the hip joint may require assessment and treatment of movement patterns during functional tasks. Patients with chondrolabral pathology demonstrate reduced balance and increased femoral adduction during a single-leg squat [41]. This potentially places the hip into a position of impingement and loads vulnerable anterior structures. Improving the motions of the hip (i.e., reducing hip internal rotation and adduction) and trunk lateral lean may reduce load on the anterior hip. This may be addressed through hip abductor, adductor and rotator strengthening and balance, trunk strength and movement retraining programmes. Increased femoral adduction

Treatment

during single-leg tasks will result in increased impingement and may prolong the athlete’s symptoms. Adequate femoral control without excessive adduction must be gained in all balance and functional tasks. Athletes with speciϐic strength deϐicits of the trunk, hip abductors and hip adductors should address these in targeted strength programmes as well as in functional and balance retraining. Adequate control of the femur during single-leg tasks is essential before an athlete can return to sports, especially when fatigued. This can be achieved using speciϐic motor control training of functional tasks as well as training to address strength endurance to prevent fatigue-related loss of control.

21.7.5 Improve Trunk Muscle Strength Trunk muscle strength is an important target for athletes with hip pain, given that it is impaired in people with hip pathology and, when reduced, increases acetabular retroversion and impingement. When the patient performs trunk exercises, the clinician should ensure the exercises are pain-free and the hip is not placed in positions of impingement. The patient should avoid over-using secondary trunk muscles, such as the iliopsoas, as this may increase impingement and hip pain. Exercises such as sit-ups, where the hip ϐlexors are commonly used, may exacerbate these symptoms and should be avoided.

21.7.6 Optimise Gait Biomechanics Speciϐic activities to normalise gait biomechanics and improve gait performance and endurance should be progressed in a structured, graduated fashion. This should also include running, direction change and cutting manoeuvres speciϐic to the athlete’s functional demands. If required, this should also include stairs and hill training (up and down). Generally, patients with hip pain have a reduced step length to avoid increased joint-loading seen at end-range hip extension. Any modiϐication to gait should not increase the athlete’s hip pain.

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21.7.7 Optimise Functional Task Performance Once good neuromotor control of the deep hip stabilisers and global hip muscles has been regained, functional and sports-speciϐic activities should be assessed and then undertaken, both to retrain these movement patterns and also to ensure the athlete can cope with these activities without failing. Any retraining of functional activities should focus on preactivation of the deep hip stabilisers, adequate control of the lumbar spine and pelvis during the activity and correct alignment of the femur during weight-bearing tasks. Retraining of hip stabilisers should be performed in the positions which place the hip at the greatest risk of overload, such as direction change and pivoting, deep squatting and kicking. They should be undertaken in a repeated fashion, again to ensure the athlete does not fail in a controlled environment.

21.7.8 Address Adverse Loading The most effective way to unload and protect speciϐic structures of the hip varies slightly for different pathologies, depending on our understanding of the functional anatomy and biomechanics of the hip. When addressing the loads on various hip structures, the principles of management of neuromotor control and remote factors should also be applied. Managing the load on the hip can be particularly difϐicult as the athlete may need to increase provocative loads on the hip in daily tasks. Thus it is vital that the ability to climb stairs, squat, put on shoes and perform everyday activities such as getting in and out of a chair is undertaken in such a way that these activities do not aggravate the underlying pathology.

21.7.9 Address Other Remote Factors That May Be Altering the Function of the Kinetic Chain As outlined previously, a number of remote factors (e.g., lumbopelvic control, ankle dorsiϐlexion range) are likely to inϐluence the rehabilitation of hip pain and pathology. Therefore, all potential contributing factors should be addressed and treated appropriately.

Treatment

21.7.10 Criteria for Returning to Sport as the Final Stage of Hip Rehabilitation The decision regarding a patient’s readiness to return to sports is made using clinical judgment of the individual’s functional capacity. In the absence of robust scientiϐic evidence, the following criteria are suggested: ∑ Performance on the one-leg-hop test (or other singleleg functional tests) at least 90% of the uninjured side (if unilateral symptoms) ∑ Performance on strength tests at least 90% of the uninjured side (if unilateral symptoms) ∑ Performance of functional tasks and sporting activity which does not reproduce hip pain and in which the athlete has adequate control of the hip to avoid impingement, even under conditions of fatigue

21.7.11 Surgical Management of the Injured Hip Hip arthroscopy is now commonly performed to manage intraarticular hip pathologies, including FAI, labral tears, chondropathy and ligamentum teres tears [42]. Hip arthroscopy has revolutionised hip surgery, since this minimally invasive procedure is associated with considerably less morbidity than open procedures. Internationally, the number of hip arthroscopy procedures now performed is growing rapidly. Clinically, patients presenting for hip arthroscopy surgery tend to be grouped into two categories – those diagnosed with morphological variations, with or without soft-tissue injuries requiring surgical intervention, and those not requiring bony intervention but presenting with soft-tissue injuries requiring intervention. The ϐirst group includes patients with FAI, which may be cam, pincer or mixed impingement. This group may also have coexisting labral pathology, ligamentum teres pathology or chondral lesions. The second group includes those with soft-tissue pathologies but without morphological change requiring surgical intervention. This group may include labral pathology, ligamentum teres pathology, chondral lesions or any combination of these. They may

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have coexisting issues such as dysplasia or hypermobility, which predispose them to such injuries but do not themselves require surgical intervention. This group may also include patients with essentially normal morphology but who undergo a massive single episode of excessive range (usually rotation), which causes trauma to the associated soft tissues. The body of evidence examining outcomes following hip arthroscopy is growing rapidly. Systematic review evidence shows that patients without chondropathy have favourable outcomes for up to 10 years (no osteoplasty) and 3 years (with osteoplasty) [42]. Patients with chondropathy have worse outcomes than those without, especially when chondral damage is severe, and risk progressing to total hip replacement within 2 years. Prior to surgery, it is important that patients trial the conservative treatments outlined. There are still no known published randomised controlled trials (RCTs) examining the effectiveness of hip arthroscopy, although these studies are underway internationally and will provide deϐinitive evidence of the efϐicacy of hip arthroscopy for subgroups of patients with intra-articular hip pathology in the coming years. The majority of the literature focuses on outcomes following surgery for FAI, labral pathology, chondropathy or combined pathology and is level III and IV evidence.

21.7.11.1 Rehabilitation following hip arthroscopy Rehabilitation programmes essentially follow the same conservative principles of management outlined before. The individual pathology treated during hip arthroscopy should inϐluence the post-operative rehabilitation programme to ensure it is adequately unloaded and protected whilst healing. This generally involves a period of partial weight-bearing as tolerated on crutches until a pain-free normal gait pattern is achieved. Generally osteoplasties performed for the correction of FAI must be protected for at least 6 weeks, while mircrofracture surgery performed for chondral defects may be protected through non- and partial weight-bearing for at least 3 months. Labral debridement and repairs [43] should be protected for at least 6 weeks, ensuring the athlete avoids potential positions of impingement through activity modiϐication and normalisation of neuromuscular control around the hip.

Some Other Major Pathologies

Injuries to the ligamentum teres should be protected for at least 6 weeks by avoiding end-range positions which place the ligament under stress and ensuring excellent neuromotor and proprioceptive control around the hip. During this initial protective phase, the athlete should commence active rehabilitation of the deep hip stabilisers, initially in an isolate fashion and then progressing into functional activity in a safe manner. The therapist should also address any overactivity of the secondary stabilisers, such as the long adductors, proximal gluteals, tensor fasciae latae and hip ϐlexors, in this period. Once this protective phase is complete, the athlete should undertake a dynamic rehabilitation programme, ensuring full strength of all muscle groups around the hip and normal function of the whole kinetic chain and sports-speciϐic activity. Generally, most athletes return to full sport between 3 and 5 months post-operatively following hip arthroscopy, although this will vary depending on the level and type of sport played, as well as the speciϐic pathology and surgery performed.

21.8

Some Other Major Pathologies

21.8.1

Proximal Hamstring Tendinopathy

The hamstrings are a commonly strained and injured muscle group during sporting activity. Proximal hamstring tendinopathy (PHT) is a commonly encountered problem in sports which involve longdistance running, jumping or repeated hip ϐlexion. It is usually characterised as an activity overload–related condition culminating in pain, impaired performance and extended periods of rehabilitation [44]. PHT is experienced by athletes across a wide variety of sports, but it is often seen in middle- and long-distance runners and occasionally sprinters [45]. Initially, PHT pain is mild during the sport or activity, but it soon progresses and completely stops the athlete from performing. PHT pain can then progress to be felt in normal daily activities, such as walking and climbing stairs, for prolonged periods or when stretching the hamstrings or gluteal muscles.

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The primary cause of PHT is mechanical overload of the tendon, and the most common factor in its aetiology is sudden change or increase in training duration, intensity or method. Therefore, a thorough and detailed subjective history of the athlete’s training history is essential. Attention should be given to any sudden increase in amount or intensity or to activities that involve greater hip ϐlexion movements, such as hill sprints, weighted deadlifts, lunges or squats. These activities create high levels of proximal hamstring tendon compression against the ischial tuberosity, which, if not progressed steadily or given enough time for adaptation, can be primary factor for development of tendinopathy.

21.8.1.1 Examination Neurodynamic testing can be highly provocative for PHT simply due to the action of stretching the hamstring tendon insertion, but also by compressing the tendon onto the ischial tuberosity. Imaging of the suspected PHT and the ischiogluteal bursa can be used to conϐirm diagnosis. MRI and ultrasound scans can often show a thickened tendon, intrasubstance heterogeneity and increased signal intensity.

21.8.1.2 Treatment The primary treatment for any tendinopathy must always be staged, progressive loading [46].

21.8.1.2.1 Initial treatment Treatment for PHT should be focused to reduce pain and minimise compression of the tendon against the ischial tuberosity. Advise the athlete against stretching the hamstring or gluteal muscles and to avoid positions of sustained hip ϐlexion, such as prolonged sitting, as much as possible. Treatment can also be directed towards relieving symptoms, using soft-tissue techniques on the posterior thigh and gluteals, applying ice and prescribing analgesic medication, if needed. Isometric contractions can also be very beneϐicial in the early stages of tendinopathy, producing an analgesic effect as well as maintaining load through the musculotendinous unit. This should

Some Other Major Pathologies

be done regularly and intermittently throughout the day in groups of three to ϐive repetitions at a time. Good examples are the prone hamstring curl and the supine bridge position. Hydrotherapy can also be useful in the early reactive stages to allow loading and movement, while reducing weight-bearing forces and pain.

21.8.1.2.2 Intermediate stage treatment Intermediate PHT rehabilitation exercises should incorporate eccentric action as well as increased load and resistance, while minimising positions of high tendon compression. Prone hamstring curls are a simple, effective method to load hamstrings.

21.8.1.2.3 Final stage of treatment The ϐinal stages of rehabilitation should include progressive higher speed, plyometric and ballistic movements, such as bounding, hopping and jumping; heel ϐlicks; and high knee drives. They are an essential component for full and safe return to sporting activities.

21.8.2

Sacroiliac Joint Dysfunction

Sacroiliac joint (SIJ) dysfunction is a broad term which has no clear diagnosis. The SIJ is a highly debated and controversial source of low back and buttock pain in sports, with it being accused of moving too little, too much or even subluxating or popping out of position. The prevalence of SIJ dysfunction varies greatly in the literature, with estimates ranging between 15% and 30% and even as high as 50% in certain sporting populations [47]. Many of the gold standard tests, such as imaging and diagnostic local anaesthetic, cannot be relied upon for SIJ dysfunction. Imaging alone cannot differentiate symptomatic from nonsymptomatic SIJ dysfunction. Local anaesthetic injections leak out of the joint and affect other tissues and nerve roots around the pelvis. There is also controversy and disagreement on how and why SIJ dysfunction can cause pain.

21.8.2.1 Functional anatomy There is wide variation described in the literature as to how much normal movement occurs at the SIJ. Some describe up to 8 mm of

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translation, while others describe much less, between 1.4 and 3.1 mm [48]. However, it is agreed that although there is movement at the SIJ, it is minimal. SIJ kinematics are highly complex due to the interaction of the many forces from the upper and lower limbs as well as the spine.

21.8.2.2 Clinical features An athlete with SIJ dysfunction can report a deep, diffuse, usually unilateral buttock pain which may be triggered after a change in activity level. SIJ pain is more likely to be reported below the level of L5 and possibly more directly over the SIJ but rarely over the ischial tuberosity. Pain can also occasionally be felt bilaterally and sometimes refer distally down the posterior and lateral thigh. Aggravating factors tend to be activities which increase forces of load through the SIJ, such as sitting, walking, lumbar spine movements and sporting tasks. Easing factors can be resting in supine position but side-lying can be uncomfortable. The best way to determine if the SIJ is a source of buttock pain is with a cluster of pain provocation tests [49].

21.8.2.3 Treatment The management of a patient with suspected SIJ dysfunction must be multimodal to reϐlect the psychosocial nature of pain as well as the complex anatomy biomechanics and relationships which this area has with surrounding structures. Manual therapy techniques in and around the pelviclumbar spine and buttocks, joint mobilisations and manipulations have been advocated. The effects achieved with manual therapy around the SIJ are not fully understood, and peripheral neuromodulation of the soft tissue and joint mechano- and nociceptors reduce sensations of stiffness and pain rather than biomechanical or structural mechanisms [50]. Corticosteroid injection in and around the SIJ can help alleviate pain in the short term, but as previously mentioned, the injected material often leaks out from the joint and can affect other surrounding tissues, which needs to be considered. The use of sclerosing prolotherapy injection has been advocated in the management of SIJ pain [51]. There is a belief that these

Some Other Major Pathologies

injections act as a trigger for ϐibrosis of the sacroiliac ligaments and help restore stability around the joint. Although initial treatments for an athlete with SIJ dysfunction can focus on pain relief and symptom modiϐication, ultimately the primary treatment is to restore the capacity of the SIJ and its surrounding tissues to withstand load, stress, shear and strain with a progressive strengthening and functional exercise rehabilitation programme. In the initial stages this may begin with non-weight-bearing exercises which focus on the muscles of the posterior chain, the erector spinae, gluteals and hamstrings. Exercises such as bridge and their progressions can be combined with exercises which also strengthen the abdominals. Progression of exercise should include moving into weight-bearing positions, focusing on a single plane of movement, such as squats and deadlifts, progressing the resistance and load as symptoms improve. More complex movements involving different and multiple planes of movement, and variable loads and speeds, can be incorporated as the athlete improves, ultimately looking to return the athlete back to full participation in his/her sport.

21.8.3

Myofascial Pain

Strains to the lumbar, buttock and posterior thigh muscles, sacroiliac ligaments and other soft tissues are arguably the most common cause of back and buttock pain in athletes. It is estimated that up to 97% of all sporting injuries are soft tissue in nature [52]. A softtissue injury is often reported as a fairly localised pain which is aggravated by continued activity or resistance. The hip muscles can often become overloaded, strained and painful during sports, and this may be due to poor training programme design, training error or a biomechanical deϐicit or muscle weakness. Palpation of the soft tissue is used to locate areas of myofascial pain, feeling for localised areas of tightness, muscle knots or taut bands. These are commonly referred to as ‘trigger points’ and may be adverse areas of sustained muscle ϐibre contractions.

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21.8.3.1 Examination A lack of gluteal muscle strength can be a common cause for buttock pain in an athlete. A common sign of gluteal muscle weakness is Trendelenburg’s sign. This is a drop of the contralateral pelvis or a compensated hitch or lateral lean of the trunk when standing on one leg. This can be difϐicult to notice in ϐit and strong individuals and can sometimes only be identiϐied when the athlete is fatigued or asked to stand on one leg for extended periods [53].

21.8.3.2 Treatment of myofascial buttock pain If weakness is found in the gluteal muscles, a well-rounded, progressive strength and conditioning programme needs to be adopted to address it which incorporates both isolated and functional multijoint compound exercises in weight-bearing positions. Treatment for tender tight muscle bands or trigger points is often performed with soft-tissue techniques such as ischaemic pressure with the thumb or elbow or via invasive techniques such as dry needling or injections.

21.8.4

Lateral Hip Pain

Lateral hip pain is a common presentation particularly among distance runners and women over the age of 40. Local soft-tissue pathology may mimic or coexist with hip joint and lumbar spine pathologies, so a full differential diagnosis will be required. Hallmarks of a local pathology include speciϐic areas of pain and tenderness either at the greater trochanter or at the iliac crest.

21.8.4.1 Greater trochanteric pain Patients with trochanteric pain complain of pain and signiϐicant tenderness over the greater trochanter, particularly lying on their side at night. The pain may radiate from the greater trochanter, most commonly down the lateral aspect of the thigh to the knee, and occasionally extending into the upper lateral leg along the line of the ITB. Tasks that involve a single-leg weight-bearing phase such as standing on one leg to dress, ascending stairs or hills and, particularly, involving higher eccentric loads or a stretch shortening

Some Other Major Pathologies

cycle, such as running, bounding or hopping, are usually reported as provocative. Traditionally the primary local source of trochanteric pain was thought to be the trochanteric bursa; however, there are a number of soft-tissue structures at the greater trochanter which have nociceptive capacity. Less common ϐindings include thickening of one or more of the three associated bursae and the region of the ITB crossing the greater trochanter. Imaging studies have demonstrated that soft-tissue pathology in this patient population most commonly presents in the gluteus medius and/or minimus tendons. While medical comorbidities may compromise tendon function and load-bearing status, mechanical loading is a potent driver of biological processes responsible for soft-tissue structure and health [54].

21.8.4.1.1 Relevant anatomy Mechanical load within the local soft tissues will be inϐluenced by the relative anatomical relationship between these tissues and the underlying bony greater trochanter in different postures and dynamic function. As the gluteus medius and minimus tendons wrap around the greater trochanter on their course to their insertion sites, they are separated from the underlying bone by their relevant bursae (subgluteus medius and subgluteus minimus bursae). The trochanteric bursa, often now referred to as the subgluteus maximus bursa, sits superϐicial to these tendons and beneath the thick, ϐibrous ITB. Mechanical load may be applied longitudinally (tensile load) or transversely (compressive load) across the tissues. Excessive compressive load is an important aetiological factor in the development of insertional tendinopathies [55], engendering changes within the soft tissues which may ameliorate compression but subsequently reduce tensile loading capacity.

21.8.4.1.2 Pathology The gluteal tendons and bursae may become compressed between the underlying greater trochanter and the overlying ITB, while the ITB itself may also be exposed to compression against the greater trochanter. Compression increases tenocyte production of larger

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proteoglycan molecules (aggrecan and versican) [56] which bind water within the tendon, resulting in a thicker tendon more resistant to compression. There may also be a shift within a compressed tendon to cartilage-like cells, which are particularly robust for compressive loading. Thickening of the associated bursae and the ITB are also likely to represent a response to excessive compression. Unfortunately this seemingly successful adaptation to compression results in reduced tensile loading capacity of a tendon due to concurrent disorganisation and enzymatic resorption of large type 1 collagen ϐibres. Compressive loading of the trochanteric soft tissues may be accumulated during static postures such as standing in adduction or sitting with knees crossed or together or during dynamic functional tasks completed with excessive lateral pelvic tilt or shift. Tendons which have adapted to compression may then fail at lower tensile strain rates. Consistent with this scenario, gluteal tendons in those with lateral hip pain have been shown to be either thicker than normal (likely in the earlier adaptive stage) or attenuated and thinner with partial or full thickness tearing (later stage when the compromised collagen ϐibres yield under tensile loads). Birnbaum and colleagues determined that as the hip moves from neutral adduction, where the ITB exerts 4 N of compressive load on the greater trochanter and intervening tissues, loads rise 9-fold by 10° of adduction and over 25-fold by end-range 40° adduction [57]. Running with a midline or cross-midline striking pattern, on the camber of a road or the same direction around a track may increase the risk of developing lateral hip pain, perhaps due to the cumulative loading stimulus.

21.8.4.2 Iliac crest pain Lateral hip pain may also emanate from soft-tissue sources at the iliac crest, with local pain and tenderness over the region of origin of the tensor fasciae latae (TFL) and ITB and adjacent fascia, with pain radiating most commonly over the anterolateral hip towards the greater trochanter. In such patients, thickening, increased water content and partial tearing have been noted on MRI in the TFL tendon of origin, the proximal ITB and the gluteal aponeurotic fascia which covers the gluteus medius, all of which anchor along the iliac crest.

Some Other Major Pathologies

It is reasonable to conceive that as the hip moves into adduction, the ITB and the gluteal aponeurotic fascia will also wind ϐirmly around the iliac crest, with the iliac tubercle providing the most prominent bony cam region. In running athletes, this condition is an overuse injury with reports of gradual onset worsening with activity over a number of months. The clinician should be aware of the same issues as for greater trochanteric pain – assessing and controlling exposure to hip adduction during static postures and functional loading.

21.8.4.3 Examination of the patient with lateral hip pain Distinct tenderness on direct palpation over the greater trochanter or iliac tubercle is a key ϐinding which determines whether lateral hip pain is originating from a local soft-tissue source. A lack of local tenderness would strongly indicate that other more remote condition should be considered. However, tenderness alone is not sufϐicient for a ϐirm diagnosis. Lumbar screening and a full hip joint assessment should be undertaken. Range-of-motion tests are usually unremarkable, helping to differentiate from primary hip joint pathology. In a meta-analysis of diagnostic accuracy of clinical hip tests, the only test to show a strong ability to inϐluence the likelihood of a positive diagnosis of gluteal tendinopathy was the resisted external rotation de-rotation test. The test winds the ITB and fasciae latae over the greater trochanter in hip ϐlexion and external rotation and then superimposes an active contraction of the gluteus medius and minimus via resisted internal rotation, combining compressive and tensile loads across the greater trochanter. Adding hip adduction will further increase compressive load and therefore may be useful as a test variation. In the 30 s sustained single-leg stance test, when performed as a pain provocation test, rather than a traditional Trendelenburg’s test, reproduction of pain over the greater trochanter within 30 s of standing on one leg was shown to have good sensitivity and speciϐicity for the detection of gluteal tendinopathy. Diagnostic ultrasound can be performed to determine if thickening is present in the bursae or ITB or to look for thickening, thinning or hypoechoic changes which are consistent with tendinopathy and

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tears. MRI is the gold standard for assessing tendinosis and tears of the gluteus medius and minimus tendons. While imaging studies are useful as an adjunct to clinical assessment where the diagnosis is unclear or the patient is failing to respond to treatment, they should not be used as a stand-alone medium for determining the source of lateral hip pain: This is due to the high prevalence of soft-tissue abnormalities in this region which may occur in the absence of lateral hip pain.

21.8.4.4 Treatment of the patient with lateral hip pain The principles of treating lateral hip pain are consistent with other insertional tendinopathies. First, manage the pain by controlling soft-tissue loads at the greater trochanter or iliac crest. Introduce graduated strengthening of the involved musculotendinous complex, aiming to improve load tolerance and optimise abnormal movement patterns. Return to sports is closely monitored to ensure volume of tendon load is controlled, time for adaptation is allowed and recurrence is avoided.

21.8.4.5 Managing pain Managing pain will primarily involve removing or minimising potentially provocative loads and instituting pain-relieving loading techniques. Reduction of compressive loading will require minimisation of sustained, repetitive or loaded end-range adduction. Positional habits such as sitting with knees crossed or together or standing ‘hanging on one hip’ in adduction should be discouraged. Sleeping postures should also be addressed, educating the patient to sleep in supine, quarter from prone or, if side-lying is unavoidable, to use pillows between the legs to reduce adduction of the uppermost side. An eggshell overlay for the lowermost side is recommended. ITB and gluteal stretches involving hip adduction should be avoided. Provocative physical activities should be suspended or modiϐied, such as long-distance, high-speed and hill running, or for the more severe presentation, all running may need to be temporarily suspended. Runners should stay on the ϐlat or run in straight lines rather than on a camber or around a track; polymeric drills such as jumping, bounding and hopping, particularly using stairs or boxes, should be avoided.

Some Other Major Pathologies

While corticosteroid injection may reduce pain in the short term via interactions with local neuropeptides and neurotransmitter, the effect is not long lasting [58]. It fails to address the underlying patho-aetiological issues and may even hinder a tendon’s capacity to respond appropriately to loading via the down-regulation of ϐibroblastic production of collagen. Shockwave therapy reduces lateral hip pain. However, it is recommended that shockwave therapy be reserved for those who fail a load management and exercise approach [59].

21.8.4.6 Managing load: First-line treatment Exercise for the hip abductor musculature begins with isometric abduction in neutral or slight hip abduction to minimise compression. This may be completed in side-lying (affected side up with pillows between legs), supine with a belt around the lower thighs or standing. The patient should slowly ramp up the contraction to a 25% maximum voluntary isometric contraction level initially, which allows time for good gluteus minimus and medius recruitment and avoids dominance of the TFL. The strengthening phase includes exercises which directly target the hip abductors and functional loading tasks with a focus on strict control of hip adduction through graduated levels of difϐiculty. Side-lying ‘clams’ (hip abduction/external rotation – hip adduction/internal rotation) are generally provocative, possibly due to the compression and friction that the ITB imparts on the soft tissues as it passes over the greater trochanter; they should therefore be avoided. Bridging and functional strengthening progressions begin with bilateral loading, progressing to offset and then single-leg tasks, allowing hand support where necessary to optimise pelvic control and minimise hip adduction and therefore compression, which is the ϐirst priority. Athletes can then progress to more complex sportsspeciϐic tasks. For running athletes, visual biofeedback and increase in cadence have been shown to be effective in reducing peak hip abduction [60]. For those who fail conservative management, usually older non-athletic individuals, there are surgical options which include

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ITB release around the greater trochanter and/or bursectomy and tendon repair as required [61]. Outcomes are generally reported as good to excellent.

21.9 Less Common Causes of Hip Region Pain 21.9.1 Piriformis Syndrome It was ϐirst described in 1947 as an enlarged or inϐlamed piriformis muscle mechanically compressing the sciatic nerve, causing buttock and posterior thigh pain [62]. Variation in the path of the sciatic nerve around or even through the piriformis has been described as a potential cause for this condition. It has been proposed that up to 5% of all buttock pain is related to piriformis syndrome [63]. Piriformis syndrome may be more common in sports which involve frequent hip ϐlexion, internal rotation and adduction, such as cycling, skiing, dancing and gymnastics. It can occur with a gradual insidious onset as well as through a traumatic event. Pain is usually reported in the mid-buttock area and described as deep and diffuse. It tends to increase with seated positions more than standing, and pain may be felt when stretching the buttocks. Clinical examination of an athlete with suspected piriformis syndrome should try to exclude the more common causes of pain, such as the lumbar spine pain, sciatic neuropathy, hamstring tendinopathy and dysfunction of the SIJ and its ligaments. Special tests used to conϐirm piriformis syndrome are active resistance tests for the piriformis, challenging its actions of hip extension from ϐlexion and external rotation, and are often called the Pace and Beatty tests. Other special tests for piriformis syndrome are passive stretch test of the muscle in position of hip ϐlexion and internal rotation, often called the ϐlexion, adduction and internal rotation (FAIR) and Freiberg tests. As with other causes of buttock pain treatment should ϐirst be prioritised to help reduce pain and modify symptoms. This may be achieved with manual therapy techniques, such as soft-tissue

Less Common Causes of Hip Region Pain

massage and stretching of the piriformis. Self-applied methods using tennis and golf balls can be taught. There is a possible role for local anaesthetic injection in the management of piriformis syndrome; however, there seems no advantage in adding corticosteroids to it. Once symptoms have reduced, the focus should be directed towards strengthening the buttock muscles and their action of hip extension and abduction. Surgical release should only be considered as a last resort in chronic refractory cases [64].

21.9.2 Ischiofemoral Impingment A rarer type of hip impingement occurs between the lesser trochanter of the femur and the ischium, called ischiofemoral impingment (IFI), and this can manifest as atypical groin or buttock pain. IFI is believed to be due to abnormal or repeated contact between the lesser trochanter of the femur and the ischium, usually when in positions of hip extension, adduction and external rotation, for example, when ballet dancers perform their poses and positions. This abnormal pelvic and leg position could cause adverse contact and compression and then injury to the quadratus femoris (QF) muscle, a strong adductor and external rotator of the femur and hip stabiliser. There are no clinical diagnostic special tests for IFI. To diagnose IFI, an MRI is needed which shows QF muscle oedema and/or a reduced space between the ischial tuberosity and lesser trochanter of the femur.

21.9.2.1 Treatment Conservative management options for IFI are initially to provide advice and education regarding activity modiϐication to reduce symptoms and allow for soft-tissue recovery. Manual therapy can help reduce soft-tissue pain. Once pain has settled, a progressive strengthening programme should be started to address any weakness found around the hip, trunk or lower limb which may have predisposed the QF to adverse compression. Consideration should also be given to biomechanical effects, for example, ensuring there in no adverse or unnecessary crossing of the feet over the midline when running, as well as to good lumbopelvic control during sporting activities.

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21.9.3

Proximal Hamstring Tendon Rupture

Complete disruption of the proximal hamstring tendon at its attachment onto the ischial tuberosity is rare. However, complete proximal hamstring tendon ruptures are seen in sports which have a risk of traumatic sudden hip ϐlexion with the knee remaining in near full extension, such as water skiing and gymnastics [65]. These traumatic mechanisms cause the athlete to experience sudden severe pain frequently with a sensation of tearing or popping around the upper posterior thigh, and usually the patient will not be able to bear weight. An observable and palpable deformity may be seen and felt when prone. Knee extension will be grossly weak, and walking will be difϐicult due to pain. Conϐirmation of the extent of the avulsion is best done with MRI or ultrasound scanning.

21.9.3.1 Treatment The decision between conservative and surgical management for proximal hamstring rupture injury is not clear. Some advocate conservative treatment if there is less than 2 cm of retraction seen on imaging. Others suggests all are surgically repaired to ensure complete return of normal muscle strength and power and to maximise chances for return to sports [66]. Conservative treatment for hamstring avulsions should ϐirst recognise and ensure that the athlete’s expectations are realistic and he/she is fully aware of the extended time this injury will take to recover. Treatment should focus on pain relief and ofϐloading the hamstrings with crutches until weight-bearing can be tolerated. Once weight-bearing is comfortable then a progressive strengthening and conditioning programme can begin. However, long-term deϐicits in strength, power and endurance can persist. Surgical repair for hamstring avulsions is becoming an increasingly popular management option for both acute and chronic hamstring avulsion, with higher levels of patient satisfaction and return to play, greater strength and endurance, and less pain [67].

21.9.4

Avulsion Fracture of the Ischial Tuberosity

Avulsion fractures of the ischial tuberosity are similar to complete proximal hamstring tendon ruptures but are usually seen only in adolescents. The age range for these injuries is between 11 and 17

Groin Pain in Athletes

years old (mean 13.8 years). Conϐirmation of an avulsion fracture can be made with an ultrasound or MRI scan, but it can also be seen on a plain radiograph showing a displaced bony fragment away from the ischium. Management is usually conservative and should be treated the same as a proximal hamstring tendon rupture. However, if the bony fragment is seen to be displaced more than 2.5 cm, surgery may be recommended to restore congruity of the tendon and ensure return to sports [68].

21.9.5

Stress Fracture of the Sacrum

Sacral stress fractures are rare and most frequently seen in osteopenic female runners, possibly to menstrual and/or eating disorders [69]. The clinical presentation can be variable and very similar to SIJ dysfunction. The main complain is usually acute low back or pelvic pain associated with a severe reduction in mobility and a possible radiation to the leg, groin, buttocks and thighs. Symptoms are increased with weight-bearing activity and improve with rest and lying supine. Tenderness over the sacral area is common. Neurological defects are usually absent.

21.9.5.1 Diagnosis confirmed by MRI and CT scans The principle treatment is a short period of rest to reduce pain and then progressive early mobilisation to encourage weight-bearing stimulation of osteoblastic activity, as well as maintaining bone density, muscle tone and tension, and limiting atrophy and stufϐiness.

21.10 Groin Pain in Athletes Groin pain and injury is common with sports which involve kicking, rapid acceleration and deceleration, and sudden change of direction [70]. The patients who present with groin pain often have diffuse, poorly localised pain and multiple clinical ϐindings. Adductor-related groin pain is the most common groin injury in football and ice hockey. Meta-analysis shows that athletes with hip and groin pain have: ∑ Pain and lower strength on adductor squeeze test

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∑ Reduced hip internal rotation and bent knee fall-out, but with hip external rotation the same as controls ∑ Lower PROM scores ∑ Altered trunk muscle function

21.10.1 Terminology The preferred umbrella term is ‘groin pain in athletes’. This is favoured over others (e.g., athletic pubalgia, athletic groin pain, sports groin pain, athletes’ groin) because it is clearly descriptive and cannot be misunderstood to be a diagnostic term [71].

21.10.2 Classification ∑ Acute groin injuries ∑ Long-standing groin pain

21.10.3 Clinical Overview It is important to appreciate the anatomy of the hip and groin and undertake a careful history and examination. The clinical approach can be difϐicult as the anatomy around this region is complex and often multiple pathologies coexist. Pain may be difϐicult to localise and be accompanied by vague symptoms. The athlete experiences groin pain, which is usually located in the medial upper thigh around the proximal adductors and pubic rami. Groin pain in athletes in aggravated by exercise, with running, twisting/turning and kicking being the most challenging activities. The athlete and coach usually notice a decrease in sports performance, especially related to performing explosive sporting actions such as kicking, accelerating/decelerating and turning.

21.10.3.1 Pain pattern The onset of groin pain in athletes can be acute or gradual, but with both types of onset, groin pain can become long-standing. In the early stages, the long-standing groin pain patient typically present late during the physical activity or after activity, with pain and stiffness next morning. The pain and stiffness then gradually lessen

Groin Pain in Athletes

with daily activities and warming up for the next training session or match. When the condition worsens, pain is present immediately upon exercise. Nonsteroidal anti-inϐlammatory drugs (NSAIDs) tend to decrease pain but will usually not result in a lasting cure. Short periods of rest reduce the severity of the symptoms, but on resumption of sporting activities the pain often returns to its original intensity and severity. The natural history is one of progressive deterioration with continued activity until symptoms prevent participation in the sporting activity.

21.10.3.2 Where is the pain located? The localisation of the pain is important in determining which structure may be causing the pain. Adductor-related groin pain is often located at the attachment of the adductor longus tendon to the pubic bone. Iliopsoas-related groin pain is located more centrally in the groin and proximal thigh. The type of activity which aggravates the pain gives a clue to the primary site of the problem. Side-to-side movements, kicking, twisting and turning activities which aggravate the pain suggest adductor-related groin pain. Straight-line running or jogging suggests iliopsoas-related groin pain. Pain with sit-ups and/or coughing may suggest an inguinal-related groin pain. Pain which becomes progressively worse with exercise may suggest a stress fracture or an apophysitis in young athletes. A history of associated pain, such as low back or buttock pain, indicates that the groin pain may be referred from another site (such as the hip, the SIJ or the spine). A full training history should be taken to determine if any recent changes in training (e.g., a generalised increase in volume or intensity, the introduction of a new exercise or an increase in a particular component of training) may have led to the development of the groin pain.

21.10.3.3 Assessment of severity While clinical examination is essential for diagnosing and classifying groin pain in athletes, it gives little objective information on the severity of the condition. The severity, insights into the impairments, activity limitations and accompanying participation restrictions can be measured with strength, range of motion and patient-reported outcome tools.

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21.10.3.4 Strength The assessment of muscle strength provides a better understanding of the degree of impairment in athletes with groin pain. It can be quantiϐied objectively and is a great help in monitoring clinical progress or deterioration. Adductor strength can be reliably assessed using handheld dynamometry and quantiϐied either unilaterally or as a squeeze test and is especially relevant in athletes with adductorrelated or pubic-related groin pain.

21.10.3.5 Range of motion Passive hip joint internal rotation range of motion in degrees can also be reliably assessed using a goniometer or inclinometer, although severe restrictions in passive range of motion are more closely related to hip intra-articular conditions and less often to groin pain related to tendon attachments and the pubic bone.

21.10.3.6 Patient-reported outcome measures The use of validated outcome measures should also be encouraged. In a systematic review from 2015 on the clinimetric properties of PROMs for young physically active individuals with hip and/or groin pain, the Copenhagen Hip and Groin Outcome Score (HAGOS) was recommended [72]. HAGOS is reliable, valid and responsive in athletes with hip and/or groin pain and therefore not restricted to any speciϐic pathology or entity. It measures six relevant subsets related to groin pain in athletes: including pain, symptoms, activities of daily living, participation in physical activity, sports function and quality of life.

21.10.3.7 Imaging The current evidence for the use of radiographs, MRI and ultrasonography (US) in groin pain is based on relatively few heterogeneous studies which are of varying methodological quality. The correlation between clinical ϐindings, athletes’ symptoms and the identiϐied radiological abnormalities is quiet weak.

21.10.3.8 Radiography Plain radiographs of the pelvis are commonly recommended in many cases to evaluate the hip joints and the pubic bones. Plain

Groin Pain in Athletes

radiograph of the pubic symphysis often shows osteolytic changes, irregular widening and sclerosis along the rami of the os pubis in soccer players. Historically these changes were interpreted as a diagnosis using the term ‘osteitis pubis’. These changes can also be seen before radiographic changes are present as pubic bone marrow oedema (BMO) on MRI. This is not that speciϐic for injury, but probably reϐlects the considerable strain that the pelvic girdle is exposed to in the kicking sports in particular [73].

21.10.3.9 Magnetic resonance imaging MRI is a very sensitive, but not always equally speciϐic, imaging technique. It is used widely, but the result should be interpreted with caution. The high sensitivity means that when imaging athletes with MRI many ‘abnormalities’ will be seen, but that the clinical relevance of these ϐindings is doubtful in terms of making a diagnosis or estimating prognosis. Some common MRI ϐindings are pubic BMO, adductor tendon changes and ϐindings around the aponeurosis anterior to the symphysis. Stress fractures, neoplasms and other occult bony injuries are rare, and when suspected, MRI is the best investigation. Even in seemingly healthy athletes, these should be considered as a possible cause of unexplained groin pain.

21.10.3.10 Ultrasonography US has gained increasing popularity in recent years. Scientiϐic evidence for its use in groin injuries is very limited. It has shown promise with other muscle and tendon injuries.

21.10.3.11 Computed tomography scan Computed tomography (CT) scan offers excellent visualisation of the pubic symphysis joint, but its general use in the young athletic population cannot be advised due to the signiϐicant radiation risk and a lack of data on normal ϐindings in the athletic population.

21.10.4 Acute Groin Injuries Acute injuries refer to the manner in which the athlete ϐirst felt the pain (i.e., sudden onset). In general, the system proposed in this

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section could potentially be used to classify the majority of acute groin injuries into entities. Consequently, a careful history – along with examination comprising palpation, resistance testing and stretching – is critical. In cases with severe pain, it may be hard to perform a thorough physical examination. An acute groin injury usually involves one or more musculotendinous structures. The lesion can be in the musculotendinous junction, but in some cases the tendon itself or the enthesis where the tendon inserts into the bone is the site of the injury. These injuries usually happen during explosive actions such as kicking, reaching with the leg, sudden change of direction or other movements where the muscle is being stretched during forceful contraction [66].

21.10.4.1 Diagnosis The most common acute injury in the groin is to the adductors, especially the adductor longus, which has been veriϐied both clinically and with diagnostic imaging. Good agreement between clinical diagnosis and diagnostic imaging seems to exist for acute adductor longus injuries [74]. However, acute injuries to other musculotendinous structures such as the iliopsoas, proximal rectus femoris or the inguinal canal/ conjoined tendon are more difϐicult to localise clinically in the acute stage. Acute injuries to the iliopsoas and rectus femoris are not infrequent and should be considered relevant differential diagnoses which may need imaging to be correctly identiϐied. If the initial injury is not treated appropriately in the ϐirst place or if a player is returned to sport too quickly, it may develop into a more long-standing injury. This type of injury can then take months to recover from, and what started out as minor acute injury can develop into a long-standing problem. The actual percentage of acute groin injuries which progress to long-standing groin pain in athletes is unknown. There is currently limited data on the recovery times for acute groin injuries.

Groin Pain in Athletes

21.10.5 Long-Standing Groin Pain The exact duration considered to be long-standing is not further deϐined. Long-standing groin pain can start either gradually or suddenly and does not refer to the mechanism of onset but only to the duration of symptoms. The classiϐication system has three major subheadings of groin pain in athletes: ∑ Deϐined clinical entities for groin pain: o Adductor related o Iliopsoas related o Inguinal related o Pubic related ∑ Hip-related groin pain: Pain from the hip joint should always be considered as a possible cause of groin pain. ∑ Other conditions causing groin pain in athletes: A high index of clinical suspicion is needed to identify these, and clinicians need to be alert to the possibilities, especially when the complaints cannot easily be classiϐied into one of the common deϐined clinical entities. An unclear relationship between the pain and loading during sport, nocturnal or extremely severe pain or a lack of response to treatment should trigger more suspicion. There are numerous possible causes, a number of which are listed in Table 21.4. A careful history and physical examination covering more than only the musculoskeletal system and appropriate additional investigation or referrals are critical for identifying other possible causes. Long-standing groin pain is classiϐied into the four clinical entities: adductor-related groin pain, iliopsoas-related groin pain, inguinal-related groin pain and pubic-related groin pain. The athlete can have more than one entity, in which case multiple entities can be diagnosed.

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Table 21.4 Possible causes of groin pain in athletes Other ‘‘†‡ϐ‹‡† musculoskeletal causes entities Adductor-related groin pain Iliopsoas-related groin pain Inguinal-related groin pain Pubic-related groin pain Hip-related groin pain

Inguinal or femoral hernia Posthernioplasty pain Nerve entrapment ∑ Obturator ∑ Ilioinguinal ∑ Genitofemoral ∑ Iliohypogastric Referred pain ∑ Lumbar spine ∑ Sacroiliac joint Apophysitis or avulsion fracture ∑ Anterior superior iliac spine ∑ Anterior inferior iliac spine ∑ Pubic bone

Not to be missed Stress fracture ∑ Neck of femur ∑ Public ramus ∑ Acetabulum Hip joint ∑ Slipped capital femoral epiphysis (adolescents) ∑ Perthes’ disease (children and adolescents) ∑ Avascular necrosis/ transient osteoporosis of the head of the femur ∑ Arthritis of the hip joint (reactive or infectious ) Inguinal lymphadenopathy Intra-abdominal abnormality ∑ Prostatitis ∑ Urinary tract infections ∑ Kidney stone ∑ Appendicitis ∑ Diverticulitis Gynaecological conditions Spondyloarthropathies ∑ Ankylosing spondylitis Tumours ∑ Testicular tumours ∑ Bone tumours ∑ Prostate cancer ∑ Urinary tract cancer ∑ Digestive tract cancer

21.10.5.1 Adductor-related groin pain Adductor-related groin pain is the most common acute and longstanding groin injury [74].

Groin Pain in Athletes

The patient with long-standing adductor-related groin pain usually complains of pain medially in the groin, most pronounced around the insertion of the adductor longus tendon at the pubic bone. The pain may radiate distally along the medial thigh. Pain during sprinting, cutting changes of direction and kicking the ball is a common complaint.

21.10.5.1.1 Diagnostic criteria The diagnostic criteria for adductor-related groin pain are adductor tenderness and pain on resisted adduction testing [74, 77].

21.10.5.1.2 Treatment The treatment of both acute and long-standing adductor-related groin pain will be considered together. The basis of the treatment of these conditions is exercise therapy and is based on Prof. Per Holmich’s seminal paper published in the Lancet in 1999, which was the ϐirst RCT to examine treatment regimes in adductor-related groin pain [75]. The exercise programme comprises two modules. The ϐirst module consists of speciϐic isometric and dynamic exercises to reactivate the adductor muscles and probably also modulates the pain. The athlete can have difϐiculties activating these muscles, probably as result of negative feedback caused by the pain. The second module includes heavier resistance training as well as challenging balance and coordination exercises. The exercise programme is performed three times a week, alternating with the exercises from module 1on the days in between [75]. The total length of the exercise training period is between 8 and 12 weeks. Absence from training is necessary as the functionality and strength of the adductor muscle group has to be re-established and pain brought under control without provocation by sport. Stationary cycling and general ϐitness training not involving the adductors can be allowed if pain-free. Jogging is allowed after 6 weeks as long as it does not provoke any groin pain. When the patient is able to jog and undergo his/ her regular treatment without pain, the treatment programme is completed and the athlete is allowed to gradually progress to demanding sports-speciϐic training followed by sports participation.

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No stretching of the adductor muscles should be done during this 2–3-month exercise training period [76]. Injection of corticosteroids at the adductor enthesis is not recommended as there is no documented long-term beneϐicial effect and it might make it more difϐicult to monitor the training programme needed to cure the groin pain. Adductor tenotomy is extremely rarely indicated.

21.10.5.1.3 Other nonsurgical treatments for adductorrelated groin pain Compression shorts can be used in cases where athletes continue to train and play despite ongoing symptoms. They can also be useful when athletes are not fully conϐident after long-standing injuries.

21.10.5.1.4 Manual therapy A case series followed by an RCT was evaluated as being concluded that multimodal treatment including manual adductor manipulation can result in a faster return to play, but not a higher treatment success, than a partially supervised active physical training programme.

21.10.5.1.5 Criteria for return to pre-injury competitive level Participation in the speciϐic sport, on an individual level or with the rest of the team, progressing from 30 min to 90 min of training and participating in 1–3 weeks of full training before full return to sports can be commenced, depending on the severity of the initial injury

21.10.5.2 lliopsoas-related groin pain Iliopsoas-related groin pain is the second-most common injury in the groin region. It is characterised by pain in the anterior part of the proximal thigh, more laterally than adductor-related groin pain. Iliopsoas-related groin pain can present in isolation, but may also be part of the disturbed muscle balance in the region when other structures are injured. It is an important differential diagnosis for hip-related groin pain not only because of the pain location but also since the iliopsoas with its close relation to the hip joint as an anterior stabiliser tends to get involved whenever there is a hip or groin problem. It seems to be a muscle which frequently gets involved in compensating for the overload.

Groin Pain in Athletes

21.10.5.2.1 Diagnostic criteria The diagnostic criteria for iliopsoas-related groin pain are iliopsoas tenderness and if there is pain on resisted hip ϐlexion and/or pain on stretching the hip ϐlexors.

21.10.5.2.2 Treatment The preferred treatment of iliopsoas-related groin pain aims to strengthen the hip ϐlexor muscles using isometric, concentric and eccentric contractions [69] and combining this with a series of pelvic stabilisation and balance exercises. Additional physiotherapy, including stretching, soft-tissue therapy and trigger point stimulation for symptomatic relief might also be helpful. In most cases, players can return to play in 4–6 weeks.

21.10.5.3 Inguinal-related groin pain Inguinal-related groin pain is probably one of the areas surrounded by the most confusion when dealing with groin pain in athletes. Differing terminology has emerged from different geographical regions and the terms ‘sports hernia’, ‘sportsman’s hernia’, ‘sportsman’s groin’, ‘posterior wall weakness’, ‘incipient hernia’, ‘Gilmore’s groin’ and ‘hockey groin’ have all been used in the past [71].

21.10.5.3.1 Diagnostic criteria The diagnostic criteria for inguinal-related groin pain are. ∑ Pain in the inguinal canal region and tenderness of the inguinal canal, no palpable inguinal hernia present ∑ More likely if aggravated with abdominal resistance, or Valsava/cough/sneeze There is no attempt made to describe any possible underlying pathology, as the exact substrate is still unknown. Bulging of the posterior wall, bulging causing entrapment neuropathy, tendinopathy of the inguinal ligament, tears of the external oblique aponeurosis and tears of the conjoined tendon have all be proposed as being the pathology underlying the problem.

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21.10.5.3.2 Treatment It is recommended to commence an active exercise-based approach with a similar principal as that in the programme described earlier for long-standing adductor-related groin pain. This approach aims to strengthen the abdominal muscles, including isometric, concentric and eccentric contraction, in combination with a series of adductor- and abductor-strengthening exercises, pelvic stabilisation and balance exercises. The abdominal exercises used in the adductor programme can be used as a starting point [76], progressing into more strenuous exercises for the abdominal wall through plank exercises and then into modiϐied plank exercises with high muscle activation of both internal and external obliques. A Swiss ball can also be used in the late-stage conditioning phase before return to sports to mimic some of the external loads and forceful eccentric/ concentric contractions which the abdominals go through, especially in kicking, throwing or shooting. The total length of the exercise training period is dependent on criteria-based progression, but is generally between 8 and 12 weeks. Absence from training is again necessary as the functionality and strength of the abdominal muscle group has to be re-established, and pain brought under control without continued provocation by the sport which ϐirst precipitated the injury. When the patient is able to jog and undergo his/her regular treatment without pain, the treatment programme is completed and the athlete is allowed to gradually progress to demanding sportsspeciϐic training followed by sports participation. No excessive stretching of the abdominal or abductor muscles during the 2–3 months’ exercise training period is recommended as it can put unnecessary strain on the adductor and abdominal complex.

21.10.5.3.3 Surgery In cases where conservative treatment is not successful or surgery is considered for other reasons, it should be noted that there have been no comparative studies on the superiority of different techniques. It seems that some patients may beneϐit from conservative treatment and will be able to return to sports without having surgery. As complications from surgery are not uncommon in this region, nonsurgical treatment should be considered and exhausted ϐirst.

Less Common Injuries

21.10.5.4 Pubic-related groin pain No epidemiological data are available in the literature regarding how common pubic-related groin pain is.

21.10.5.4.1 Diagnostic criteria The diagnostic criteria for pubic-related groin pain are: ∑ Local tenderness of the pubic symphysis and the immediately adjacent bone ∑ No particular resistance tests to test speciϐically for pubicrelated groin pain identiϐied Verrall et al. described clinical signs, including pubic symphysis and superior pubic ramus tenderness, as part of a bone stressrelated problem [77]. The presence of BMO on MRI in the pubic bone was also part of the diagnosis. The clinical criteria included the presence of at least 6 weeks of groin pain, located in the adductor and/or pubic bone region and present during and/or after sporting activity. No particular resistance tests to test speciϐically for pubicrelated groin pain have been identiϐied, but squeeze testing seems to be the most relevant.

21.10.5.4.2 Treatment The treatment for this condition, as described by Verrall et al., consists of mainly unloading the lower extremities and gradually increasing load again over a period of 3–4 months, moving from rest from all weight-bearing running activities for 12 weeks over a period with stationary cycling, a stepping device and a gradual return to running activity. The athletes were allowed to return to football training when 30 min of pain-free interval running was tolerated. There is no evidence-based treatment available.

21.11 Less Common Injuries 21.11.1 Complete Adductor Avulsion Complete proximal adductor avulsions are not common, and the mean time for return to play in players treated conservatively for an acute adductor longus rupture was reported to be 3–12 weeks.

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21.11.2 Obturator Neuropathy Obturator neuropathy is a fascial entrapment of the obturator nerve as it enters the adductor compartment. Obturator neuropathy presents as exercise-related groin pain, which initially is located in the proximal groin but with increasing exercise radiates towards the distal medial thigh. There may be associated weakness or a feeling of a lack of propulsion of the limb during running, but numbness is very rarely reported. At rest, examination ϐindings can be nonspeciϐic, with pain on passive abduction of the hip and pain and weakness on resisted hip adduction. The ipsilateral pubic tubercle is often tender. The essential component of physical examination is to exercise the patient to a level which reproduces the symptoms, followed by immediate examination of the patient. This examination will reveal weakness of resisted adduction and numbness over the distal medial thigh. The diagnosis is conϐirmed by needle electromyography (EMG), which shows chronic denervation patterns of the adductor muscle group. Conservative treatment of this condition, is generally unsuccessful. The deϐinitive treatment of this condition is surgical, and the nerve is freed up to the level of the obturator foramen. Postsurgical management includes wound management, soft-tissue techniques and a graduated return to full activity over a period of 4–6 weeks.

21.11.3 Other Nerve Entrapments A number of superϐicial nerves in the groin may become entrapped and should be considered as possible causes of groin pain. The ilioinguinal nerve supplies the skin around the genitalia and the inside of the thigh and may produce pain as a result of entrapment. The genitofemoral nerve innervates an area of skin just above the groin fold. The lateral cutaneous nerve of the thigh is the most common nerve affected. This nerve supplies the outside of the thigh. This condition is known as ‘meralgia paraesthetica’. Treatment of these conditions is usually not necessary as they often spontaneously resolve. Meralgia paraesthetica is sometimes treated with a corticosteroid injection at the site where the nerve exits the pelvis, 1 cm medial to the anterior iliac spine. Occasionally, the nerve needs to be explored surgically and the area of entrapment released.

Less Common Injuries

21.11.4 Stress Fracture of the Neck of the Femur Stress fracture of the neck of the femur is another cause of groin pain. The usual history is one of gradual onset of groin pain, poorly localised and aggravated by activity. Examination may show some localised tenderness, but often there is relatively little to ϐind other than pain at the extremes of hip joint movement, especially internal rotation. Plain radiographs may demonstrate the fracture if it has been present for a number of weeks, but isotopic bone scan and MRI are the most sensitive tests (Fig. 21.6)

Figure 21.6

MRI showing stress fracture of the neck of the femur.

Stress fractures of the neck of the femur occur on either the superior or the tension side of the bone or on the inferior or compression side. Stress fractures of the superior aspect of the femoral neck should be regarded as a surgical emergency and treated with either urgent internal ϐixation or strict rest. The concern is that such stress fractures have a tendency to go on to full fracture, which compromises the blood supply to the femoral head. Stress fractures of the inferior surface of the femoral neck are more benign and can be treated with an initial period of non-weight-

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bearing rest followed by a period of weight-bearing without running. They require at least 6 weeks of rest and usually considerably longer. Following the period of rest, a further 6 weeks of progressive loading will take the patient back to full training. Biomechanical, nutritional and endocrine risk factors should be assessed and treated, as appropriate.

21.11.5 Stress Fracture of the Inferior Pubic Ramus Stress fracture of the inferior pubic ramus, especially in distance runners, is an important differential diagnosis of adductor tendinopathy. There is usually a history of overuse and localised tenderness, which is not aggravated by passive abduction or resisted adduction. In this condition, pain is often referred to the buttock. MRI will show a focal area of bone oedema. As with any stress fractures, aetiological factors must be considered. Stress fractures of the inferior pubic ramus in females may be associated with reduced bone density, low initial aerobic ϐitness and nutritional insufϐiciency. Prolonged amenorrhoea is also linked with this stress fracture. Treatment consists of relative rest from aggravating activities, such as running, until there is no longer any local tenderness. Fitness should be maintained with swimming or cycling with gradual return to weight-bearing over a number of weeks. Predisposing factors such as a negative energy intake, muscular imbalance or biomechanical abnormality also require assessment and intervention. Preventative strategies can be incorporated, especially in the female athlete population. Strategies may include pretraining interventions focusing on improving aerobic ϐitness to reduce fatigue fractures, and calcium and vitamin D supplementation [78].

21.11.6 Referred Pain to the Groin The possibility of referred pain to the groin should always be considered, especially when there is little to ϐind on local examination. A common site of referral to the groin is the SIJ, and this should always be assessed in any examination of a patient with groin pain. The SIJ may also refer pain to the scrotum in males and the labia in females. The assessment and treatment of sacroiliac problems are discussed earlier.

Prevention of Groin Injuries

The lumbar spine may refer pain to the groin. The lumbar spine and thoracolumbar junction should always be examined in a patient with groin pain. Neurodynamic tests, such as the slump and neural Thomas tests, should be performed as part of the assessment. A positive neurodynamic test result requires further evaluation to determine the site of the abnormality. The position of reproduction of pain can be used to correct neural tightness by stretching. Active trigger points may also refer to the groin and should be treated with soft tissue therapy. As mentioned earlier, there are many other conditions which can give rise to groin pain. When athletes present with groin pain which is not typical in nature and has no clear relationship with loading, nocturnal pain or pain associated with other nonmusculoskeletal symptoms, one must think broadly in terms of possible differential diagnosis.

21.12 Prevention of Groin Injuries Seven RCTs had investigated prevention of sports injuries where data on groin injuries had been included. These seven studies were evaluated and analysed in a systematic review, and the data were pooled in a meta-analysis [79]. The studies examined the effect of different prevention interventions, predominantly looking at strengthening, coordination and balance exercises, and there were more than 2000 subjects in control and intervention groups. Despite several limitations, adding an active exercise strategy for strengthening and improving muscle function, load transfer and tolerance in the pelvic region may induce a relevant reduction of groin injuries. No reports of adverse events in relation to such a strategy have been documented.

21.12.1 Possible Prevention Strategies A number of measures can be considered in clinical practice. Given the fact that previous injury is a risk factor, athletes with a history of hip pain should be given extra attention. Research on soccer players during the start of a new season has shown that those who had groin

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pain in the previous season still had reduced function and residual symptoms after the summer break [81]. In this light it would seem prudent for athletes with hip pain in season to use the off-season to concentrate on treatment and recovery rather than simply resting. A careful examination should be done at the end of the season, and any deϐicits found can be used to target improvements in the offseason and should be combined with sports-speciϐic training. The recent literature from other ϐields has highlighted that athletes who have a rapid rise in training load, without sufϐiciently accumulating training to have ensured readiness, are prone to injury. As such, careful consideration of training load can be part of hip injury prevention but is likely to be part of a more general prevention strategy than only aimed at the hip or groin.

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and groin disability: a systematic review of the clinimetric evidence. Br I Sports Med, 2015; 49(12):812. 74. Brand S, Thorborg K, Bech BH, et al. MRI ϐindings in soccer players with long-standing adductor-related groin pain and asymptomatic controls. Br J Sports Med, 2015; 4900:681–691. 75. Serner A, Tol JL, Jomaah N, et al. Diagnosis of acute groin injures: a prospective study of 110 athletes. Am J Sports Med, 2015; 43(8). 76. Holmich P, Uhrskou P, Ulnits L, et al. Effectiveness of active physical training in athletes: randomised trial. Lancet, 1999; 353:439–443. 77. Weir A, Jansen JACG, Van de Port IGL, et al. Manaul or exercise therapy for long standing adductor related groin pain: a randomized controlled clinical trial. Man Ther, 2011; 16:148–154. 78. Verrall GM, Slavotinek JP, Barnes PG, et al. Description of pain provocation tests used for the diagnosis of sports-related chronic groin pain: relationship of tests to deϐined clinical (pain and tenderness) and MRI (pubic bone marrow oedema) criteria. Scand J Med Sci Sports, 2005; 15:36–42. 79. Esteve E, Rathleff MS, Petersen P, et al. Prevention of groin injuries in sports a systematic review with meta analysis of randomised controlled trials. Br J Sports Med, 2015; 49(12):785–791. 80. Thorborg K, Rathleff MS, Petersen P, et al. Prevalence and severity of hip and groin pain in sub-elite male football: a cross sectional cohort study of 695 players. Scand J Med Sci Sports, 2015; https://doi.org/10.1111/ sms.12623. 81. Orchard JW, Men at higher risk of groin injuries in elite team sports: a systematic review. Br J Sports Med, 2015; 49:798–802.

Chapter 22

Evaluation of a Painful Total Hip Replacement

Lee Hoggetta and Ardeshir Y. Bonshahib aSpeciality Registrar – Trauma & Orthopaedic Surgery,

Health Education North West, UK

bWrightington Hospital, Hall Lane, Appley Bridge, Wigan,

Lancashire WN69EP, UK

[email protected], [email protected]

22.1

Introduction

Total hip arthroplasty (THA) is a very common operation, with nearly 100,000 primary procedures performed in the United Kingdom in 2018 [1]. It is a very effective operation with a high success rate. Over 90% of patients report being satisϐied following the procedure [2]. Additionally, 90%–95% of patients should expect to have their total hip replacement (THR) functioning at 10 years [3], and in 85%, they will still be functioning at 20 years [4]. It has been reported that up to 12% of patients may have ongoing pain 18 months following surgery which signiϐicantly impairs their daily activities [5]. The occurrence of pain following The Hip Joint Edited by K. Mohan Iyer

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arthroplasty is concerning for both the patient and the surgeon and can be challenging to diagnose and treat. In the United States the number of primary THAs is expected in increase by 174% to around 572,000 [6] by 2030, and this trend is likely to be replicated globally. With an increasing number of patients undergoing THA the number of patients with post-operative pain is expected to increase proportionally. In order that these patients are managed appropriately it is important to accurately locate the source of the pain. This can be successfully achieved in most patients with a thorough history, physical examination and appropriate investigations.

22.2

Differential Diagnosis

Pain following THA can be categorised into intrinsic and extrinsic causes [7], and the work-up, initial assessment and investigations aim to differentiate between the two. Intrinsic causes relate to problems directly affecting the implant, whether this is at the interface between the bone and implant itself or in the surrounding soft tissues. Extrinsic factors are unrelated to the implant itself. These factors are summarised in Table 22.1. Table 22.1 Differential diagnoses of painful total hip arthroplasty Intrinsic causes

Extrinsic causes

Ȉ Aseptic loosening

Ȉ Lumbar spine disease

Ȉ Infection

Ȉ Peripheral vascular disease

Ȉ Tip of stem pain

Ȉ Nerve injury/irritation

Ȉ Stress fracture

Ȉ Complex regional pain syndrome

Ȉ Peri-prosthetic fracture

Ȉ Metabolic disease

Ȉ Non-union

Ȉ Malignancy

Ȉ Instability

Ȉ Hernia

Ȉ Inϐlammatory bursitis/tendonitis

Ȉ Referred pain

Ȉ Adverse reaction to metal debris (ARMD)

Intrinsic Causes

22.3

Intrinsic Causes

22.3.1 Aseptic Loosening Aseptic loosening can be the result of inadequate initial ϐixation, the mechanical loss of ϐixation over time or osteolysis caused by particular debris resulting in biologic loss of ϐixation [8]. Aseptic loosening has been reported to be one of the most common causes of revisions, accounting for 55% of hip revisions [9]. It is important to know what prosthesis was used in order to determine the likelihood of early failure. For example, the 3M Capital THA stem had a failure rate of 20% at 5 years, with deϐinite loosening present in 16% [10]. Early loosening is usually asymptomatic, especially if only present on the acetabular side. Pain only arises at the point the implant or cement mantle becomes loose enough to transfer abnormal load onto the endosteum. The importance of serial X-rays cannot be understated in order to compare with a post-operative initial X-ray to determine implant migration or development of lucent lines (Fig. 22.1). Clinical presentation can be as groin, thigh or deep gluteal discomfort.

Figure 22.1 to right).

Serial radiographs demonstrating evolving aseptic loosening (left

22.3.2 Infection The incidence of deep infection [periprosthetic joint infection (PJI)] following THA has been reported as 0.6%–2.2% [11–13]. The overall risk of revision surgery for PJI, however, was 0.4% based on data from the national joint registry data (UK) between 2003 and 2014 [14]. PJI has been classiϐied by Fitzgerald et al. [15] into three distinct stages: stage 1 is an acute infection within 6 weeks of the primary procedure, stage 2 is delayed sepsis and stage 3 is

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a late infection in a previously well-functioning hip replacement, likely due to haematogenous spread. A fourth type has also been proposed, where a positive culture is found at the time of revision surgery without any previous evidence of infection [16]. Most infections typically involve staphylococci, with methicillin-sensitive Staphylococcus aureus being the most frequently isolated organism in both single-organism and polymicrobial infections [17]. Infection should be suspected in all cases of pain following THA and needs to be excluded in patients undergoing revision surgery for aseptic loosening. It is common practice to take tissue samples during revision surgery both to ensure that there is no active or latent infection and to prospectively isolate any organisms should the need for antibiotic treatment arise.

22.3.3

Instability

Dislocation is a common complication following THA, with reported rates between 0.3% and 10% [18]. Although dislocation of a prosthesis is clear from the history, examination and plain ϐilms, subluxation is less obvious. It can be related to component position, component wear or deϐicient soft tissues. Patients may report discomfort, likely due to soft-tissue stretch or occasionally mechanical clunking. The risk of dislocation is highest in the ϐirst 3 months, with 59% of all dislocations occurring in this period in a review of over 10,000 primary hips [19]. More recently a review estimated that the cumulative risk of dislocation in the ϐirst post-operative month is 1% [20]. Following this the risk continuously increases by approximately 1% per 5-year period and is approximately 7% after 25 years [21]. Early dislocations may be due to a provocative patient position such as deep ϐlexion or due to component positioning and need early revision if the latter is true. Isolated single early dislocations can be managed expectantly following reduction. In comparison, late dislocations are typically multifactorial in origin due to loosening of components, wear and soft-tissue compromise. As such these patients may dislocate recurrently [22] and may necessitate revision surgery. The surgical approach can be a factor in dislocation rates with, the anterolateral, direct lateral and posterior approaches having a dislocation rate of 0.70%, 0.43% and 1.01%, respectively [23]. The risk of dislocation

Intrinsic Causes

following a revision procedure is approximately three times greater than following a primary hip arthroplasty [24].

22.3.4

Peri-prosthetic Fractures

Peri-prosthetic fracture rates are increasing due to the ageing population globally and the increased number of primary and revision total hip arthroplasties being undertaken [25]. Intraoperative fractures may be occult, particularly acetabular fractures. The rate of intra-operative femoral fracture in a series of 32,644 primary hips was 1.7% overall and was signiϐicantly higher in uncemented implants (3%) versus uncemented implants (0.23%) [26]. The cumulative risk of post-operative femoral fracture is 3.5% at 20 years and is independent of gender or age [24]. The Vancouver classiϐication is commonly applied and is based on fracture location and may be used to determine treatment. ∑ A involves the trochanteric region. o AG: Greater o AL: Lesser ∑ B is around or just distal to the femoral stem (Fig. 22.2). o B1: Implant well ϐixed o B2: Implant loose but bone stock good o B3: Severe bone stock loss and a loose implant ∑ C is so far beyond the stem that treatment is independent of the hip replacement.

ϮϮ͘ϯ͘ϱ /ŶŇĂŵŵĂƚŽƌLJŽŶĚŝƚŝŽŶƐ Greater trochanteric pain syndrome (GTPS; trochanteric bursitis) is reported to be as high as 17% in arthroplasty performed using a trochanteric osteotomy [27]. Performing THA using a direct lateral approach has a reported incidence of lateral trochanteric pain of 4.9% compared to a posterior approach at 1.2% [28]. Performing via a direct anterior or posterior approach is therefore protective [29]. Pain is usually present when lying on the operated side and is well localised. GTPS has thought to be related to increasing the offset and causing resultant soft-tissue stretch. The iliopsoas tendon may also become inϐlamed, resulting in groin pain due to tendinitis. This

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can arise from an impingement as the tendon passes the leading anterior edge of the acetabular component. This is more common in a under-anteverted, retroverted or oversized acetabular cup [30]. It is essential to check at time of trial and ϐinal implantation of the component that the anterior edge of the acetabular component lies inside the anterior acetabular bony margin to avoid this complication.

Figure 22.2 Vancouver B2 fracture (left). Treatment with a fully coated porous stem and cerclage wires (right).

22.3.6

Stem Tip Pain: Thigh Pain

The aetiology of thigh pain after THA is not fully understood, and the most accepted hypothesis is that it arises from stress increasing and localising at the tip of the stem [31]. This may be due to component position, that is, a varus stem impinging the densely innervated endosteum [32] or the stem tip resting on the posterior cortex, usually seen on a lateral beam X-ray. The other theory is that there is a mismatch in the modulus of elasticity between a stiff femoral implant and the less stiff bone at the stem–tip junction. This results in the applied load being concentrated at the stem tip rather than it being dissipated evenly along the length of the femur.

Intrinsic Causes

22.3.7 Metal-on-Metal Metal-on-metal (MoM) hip replacements have fallen out of favour after higher-than-expected revision rates were identiϐied from registry data [33]. An example being the now recalled articular surface replacement (ASR) THR: 29% of patients had revision surgery within 6 years of the primary procedure [34]. The high revision rate is thought to relate to an adverse reaction to metal debris (ARMD), causing soft-tissue changes which are locally destructive. These changes can be asymptomatic for many patients, and as such various national guidelines exist to assist in the followup, investigation and management of these patients. In the United Kingdom these guidelines have been produced by the Medicines and Healthcare products Regulatory Agency (MRHA) and are outlined next [35]: In the following patient groups: ∑ Stemmed THRs (head size > 36 mm) ∑ Female patients with hip resurfacing ∑ Male patients with hip resurfacing and a femoral head size 48 mm ∑ Stemmed THR with a femoral head size