Biomechanics and Biomaterials in Orthopedics (eBook)

Foreword 6
Contents 8
Contributors 12
Part I: Introduction 17
1: Bone as Biomaterial 18
Introduction 18
The Materials Used in Orthopedics 19
Biodegradable Materials 19
Bone Replacement Materials 20
Autografts 20
Allografts 20
Xenografts 20
Bone Substitutes 20
Joint Replacement Materials 20
Capsuloligament and Joint Replacement Materials 21
Mineral Structure of Bone 21
Progression of Mineralization 21
Collagen 22
Non-collagenic Proteins 22
Proteoglycans 22
Bone Remodeling 22
Morphology and Bone Mechanics in Hypodynamia 23
Epiphyseal Cartilage 24
Articular Surfaces and Friction 24
Lubrication and Pathology 24
Finally: Tomorrow, Will Man Be Artificial? 24
Part II: Biocompatible Materials 26
2: Biomaterials Used in Orthopedics 27
Behavior of Biomaterials in Situ 27
Biomaterials Used in Orthopedics 28
Metal Alloys and Metals 28
Ceramics and Ceramic–Metal Compounds 29
The New Ceramics 30
Ceramic–Ceramic and Ceramic–Metal Compounds 30
Glass and Vitroceramics 30
Natural, Biological, or Synthetic Bone Replacement Materials 31
Materials Obtained by Synthesis 31
Allografts 31
Carbon Compounds 32
Polymers 32
3: Bioceramics 34
Definition and Classification 34
Bioinert Ceramics 34
Bioactive Ceramics 38
References 45
4: Biomaterials for Bone Tissue Engineering 47
Biodegradable Polymers 48
Solvent Casting/Particulate Leaching 49
Emulsion Freeze-Drying/Thermally Induced Phase Separation 50
Gas Foaming 50
Rapid Prototyping 50
Bioceramics 50
Calcium Phosphates 51
Biphasic Calcium Phosphate 53
Bioactive Glass and Glass-Ceramics 53
Silicate Bioceramics 56
Silicate/Phosphate Based Composites 59
Polymer/Inorganic Composites 60
Concluding Remarks 62
References 62
5: Biomaterials for Total Joint Replacements 70
Ultra High Molecular Weight Polyethylene (UHMWPE) 71
Processing 71
Sterilisation 72
Degradation and Oxidation 72
Packaging 72
Debris and Diffusion 73
Crosslinked UHMWPE 73
Vitamin E Stabilised UHMWPE 73
Polymethylmethacrylate, the Orthopaedic Cement 74
Ceramic Biomaterials 75
Oxide Ceramics 75
Alumina 75
Zirconia 76
Alumina-Zirconia Composites 77
Nitride Ceramics 77
Complications with Ceramic Bearings 77
Calcium Phosphate Ceramics 77
Metallic Materials for Joint Prosthesis 78
References 80
6: Bone Materials and Tissue Banks 82
Introduction 82
History 82
Bone Replacement Materials 85
Autografts 85
Allografts 85
Immunology of Bone Allografts 85
Fate of the Grafted Tissue 85
Biomechanics 86
Xenografts 86
Bone Substitutes 86
Reconstructions with Massive Allografts 86
Joint Replacement Options 87
Immunogeneity of the Various Constituents of Cartilage 87
Removal and Preservation of Grafts 88
Clinical Experience 88
Capsuloligament and Articular Replacements by Massive Allografts 89
Ligament Allografts 89
Mechanical Studies 89
Surgical Technique for Reconstructing the Acetabulum and the Pelvis 90
Results 91
Discussion 91
Conclusion 91
References 92
7: Bone Banks: Technical Aspects of the Preparation and Preservation of Articular Allografts 94
The Removal of Articular and Osteocartilaginous Grafts 94
Selection of the Donors 94
Removal Techniques 95
Coding and Measuring of the Parts 95
Quality Controls 95
Preservation Techniques 96
Preservation Methods 96
Biomechanics and Immunology 97
Transport 97
Use 97
Isolated Osteocartilaginous Grafts 97
Osteocartilaginous Graft Plus Ligaments from the Donor 97
Complete Articular Grafts 98
Reconstruction Prostheses Sheathed with Bone from a Bone Bank 98
Conclusion 98
Appendix 99
Recommendations for Setting Up a Tissue Bank for the Locomotor Apparatus 99
The Organization of a Tissue Bank 99
General 99
Equipment 99
Personnel 99
Techniques 99
Information 99
Quality Control 99
Tissue Removal 99
General Ethical and Legal Considerations 99
Selection Criteria 100
Preservation and Storage 100
Bibliography 101
8: Formulated Demineralized Bone Grafts for Skeletal Applications 106
History of Demineralized Bone 107
Demineralized Bone Safety 109
Screening and Initial Process 109
Aseptic Processing 110
Viral Inactivation 111
TSE Agents/Prions 112
Composition 112
Why Demineralize the Bone? 113
Basis of Healing 113
Acting Upon Cells to Influence Healing 113
Osteoinduction: Signaling/Recruitment/Differentiation 114
Measurement of Osteoinductivity 114
Factors Influencing Osteoinductivity 115
Process Effects on Osteoinductivity 116
Particle Shape 116
Grafting Strategy and Clinical Use 118
Conclusion 120
References 121
9: Bioreactors for Bone Tissue Engineering 125
Bioreactor Design for Bone Tissue Engineering 125
Spinner Flask 126
Rotating Bioreactor 126
Perfusion Bioreactor 127
Roles of the Bioreactor in Bone Tissue Engineering 128
Cell Seeding 128
Mass Transfer 128
Shear Stress 129
Prospect 130
References 130
10: Orthopedic Bone Cements 133
Polymethylmethacrylate Cement (PMMA) 134
Chemical Composition and Polymerisation of the PMMA 134
Physical and Mechanical Properties of the PMMA 135
Physical Properties 135
Mechanical Properties 135
Biological Properties of the PMMA 136
Cellular Reactions 136
Local Tissue Reactions 137
Implant Loosening 138
Secondary Reactions 138
Improvement of the PMMA 139
Calcium Phosphate Cement (CPC) 140
Chemical Compositions and Crystallisation of the CPC 140
Physical and Mechanical Properties of the CPC 140
Biological Properties of the CPC 141
Clinical Application of the CPC 143
Development of the CPC 143
References 144
11: Cement with Antimitotics 149
Study of the Release of Methotrexate (MTX) 150
The Efficacy of Methotrexate-Loaded Implants 150
Study of the Release of Cisplatin 151
Clinical Experience 152
References 152
12: Striated Muscles, an Underestimated Natural Biomaterial: Their Essential Contribution to Healing and Reconstruction of Bone Defects 154
Mechanical and Biological Factors 154
Mechanical Properties 154
The Biological Result 155
Muscle Assessments 156
Electrophysiology and Biomechanics 156
EMG vs Force Relations and  Pre-­dominant Fiber Type 156
EMG vs Force and Contraction Rate 157
EMG vs Force and Motor Units Recruitment 157
EMG Cross-Talk and Adipose Tissue 157
EMG Processing Issues 158
EMG and Muscle Fatigue 158
MVC Determination 159
References 159
13: Clinical Application of Glass Ceramics 161
Why Glass Ceramic 161
Application of AW-GC to the Spine 162
Vertebral Body Prosthesis 162
Intervertebral Spacer for the Lumbar Spine 163
Laminoplasty Spacer for the Cervical Spine 163
The Iliac Crest Prosthesis Made of AW-GC 164
AW-GC to Replace Large Bone Tumors 164
AW-GC Coating on Hip Prosthesis 164
Summary 165
References 165
14: Alumina Composite: The Present Generation of Load Bearing Ceramics in Orthopedics 166
Developments in Alumina Technology 166
Alumina Matrix Composites 167
Behavior of BIOLOX® Delta 168
Mechanical Properties 168
Transformation Toughening by Zirconia 168
New Experimental Evidence for the Impact of Platelets 169
Hardness 169
Hydrothermal Aging 170
Wear Behavior 171
Applications in New Devices 171
Clinical Outcomes 172
Conclusions 172
References 172
15: Validation of a High Performance Alumina Matrix Composite for Use in Total Joint Replacement 174
Description of Biolox®Delta 175
Correlation of Material and Component Properties 176
Effect of Hydrothermal Aging on Strength of Biolox®Delta 177
Conclusions 178
References 178
16: New Composite Material: PLLA and Tricalcium Phosphate for Orthopaedic Applications-In Vitro and In Vivo Studies (Part 1) 180
Material and Methods 181
Samples 181
In Vitro Study 181
In Vivo Study 181
Results 182
In Vitro Study 182
In Vivo Study 183
Discussion 183
Conclusion 185
References 186
17: Clinical Results of a New Resorbable Composite Material for Cervical Cage: 6 Years’ Follow-up (Part 2) 188
Materials and Methods 189
Results 189
Discussion 190
Conclusion 190
References 191
18: Shape Memory Alloys and Their Medical Applications 193
Martensitic Transformation 193
Functional Properties 194
Shape Memory Effect 194
Superelasticity 195
High Damping Capacity 196
Applications 196
Application of the Shape Memory Effect 196
Free Recovery 196
Constrained Recovery 196
Superelastic Applications 199
Self-Expanding Stent 199
References 201
Part III: Tissue Biomechanics and Histomorphology 202
19: Biotribocorrosion of Implants 203
Interface Between Metal and a Biologic Environment 203
Corrosion Damage of Implants 205
Wear Damage of Implants 207
Friction and Lubrication 208
Wear 209
Corrosion and Wear Combined 210
Clinical Implications of Biotribocorrosion 214
Methods of Testing 215
Laboratory Testing 216
In Vivo Testing 219
Mitigation of Biotribocorrosion 220
Surface Coating 220
Surface Treatment 221
Design Aspects 226
References 226
20: Massive Allografts: Techniques and Results with 30 Years’ Follow-Up 231
Allograft Biology 231
Immunology 231
Biological Integration 232
Spongious Allografts 232
Cortical Allograft 232
Bone Allograft Technology 232
Selection of Donors 232
Removal Techniques 233
Preservation Techniques 233
Preservation Methods 233
Biomechanics and Immunology 233
Transport 234
Massive Osteochondral Allografts 234
Material and Methods 234
Oncology 234
Traumatology 235
Iterative Operations 235
Results 235
Globally 235
Discussion: Global Follow-Up of 30 Years 235
Acetabulum and Pelvic Reconstructions with Massive Allografts 236
Etiologies 236
Allografts 236
Surgical Techniques 236
Reconstruction of the Pelvis 236
For Isolated Reconstructions of the Acétabulum 237
Clinical Applications and Results 237
The Mega-Hip Prosthesis Surrounded By Allografts 237
Computerized Custom Made Mega Hip Prosthesis 237
Shape 237
Fixations 238
Clinical Applications 238
Conclusion 238
Suggested Reading 239
21: Express Diagnosis of Mechano-­Biological Limb Skin Condition During Prolonged Dosed Stretching in Orthopedics 244
Technique 244
Analysis of Forearm Skin Mechanics-and-Acoustic Properties for Graduated Distraction in Patients with Congenital Anomalies of the Upper Limb 245
Thigh Skin Response to Dosed Lengthening in the Patients with Congenital Lower Limb Shortening 248
Analysis of Mechano-acoustic Skin Properties in Healthy Subjects and Its Practical Value 248
Conclusion 252
References 254
Part IV: Biomechanics of Bone Growth 255
22: Biomechanics of the Spine During Growth 256
Embryology 256
Biomechanical Consequences 257
Vertebral Growth in Space and Time 257
Vertebral Growth from Enchondral Ossification 257
Vertebral Growth Plates 258
Vertebral Growth Over Time 258
Biomechanical Consequences 259
Importance of the Soft Tissues Component of the Spinal Organ 260
Setting Up of the Erect Posture and Its Consequences 261
Getting the Erect Posture in Humans 261
Maturation of the Central Nervous System 261
Biomechanical Consequences of the Erect Posture in Children and Adolescents 262
Static and Dynamic 3D Balance 262
Cephalic and Pelvic Vertebra Concept 263
Concept of the Conus of Economical Consumption and Economical Function 263
Biomechanics of Ligaments, Aponevrosis and Muscles Surrounding the Spine for Static and Dynamic Function During Erect Posture 263
Development of the EOS System 266
Application to the Common Pathology of the Growing Spine 267
Scoliotic Deformities 268
Pathological Examples of Biomechanics Related to Spinal Balance in Childhood and Adolescence 278
Genetic Factors 281
Conclusion 281
References 281
23: Effect of Tension Stress by Surgical Lengthening of Limbs with Growth Retardation on Biomechanical and Functional Properties of Tissues 283
Techniques to Study Elasticity of Skin Integuments and Arterial Walls 284
Dynamics of Tissue Biomechanical Properties in the Process of Natural Growth and Under Surgical Leg Lengthening 288
Myotonometry 288
Effect of Muscle Biomechanical Properties on Blood Supply of the Leg Being Lengthened 290
Muscle Contractility Recovery in the Limb Lengthened 290
Constitution Type Effect on Surgical Lengthening Outcomes of a Limb with Growth Retardation 296
Conclusion 298
References 298
24: Biomechanics of Pediatric Hip 299
Congenital Dislocation of the Hip Joint 299
Treatment for Congenital Hip Dislocation 300
Configuration of the Hip Joint and Alignment of Lower Extremity 300
Femoral Antetorsion and Cooperated Factors of Torsion 301
Experimental Study of Femoral Antetorsion 301
Slipped Capital Femoral Epiphysis 302
References 305
25: Biomechanics of Fracture in Growth Period 307
Characteristics of Fractures in Children 307
The Role of Periosteum 307
Characteristics of Children’s Bone 307
Epiphyseal Injury 308
Remodeling After Fractures in Children 309
References 310
26: Experimental In Vitro Methods for Research of Mechanotransduction in Human Osteoblasts 311
Experimental Methods 311
Conclusion 315
References 315
Part V: Applications of Biomechanical Principles to Orthopedics and Traumatology 317
27: Computer-Assisted Designed Hip Arthroplasty 318
The Concept of Computer Assisted Hip Arthroplasty 318
The Computer Assisted Planning of Total Hip Arthroplasty 319
Preoperative Data 319
X-Ray Data 319
CT Data 320
Pre-operative Planning 320
Acetabular Cup 320
According Position of the Femur 320
The Computer Assisted Design of Custom Hip Stem 321
The Design of the Intramedullary Section 321
Contouring 321
Matching CT and X-Ray Data 321
Definition of Osteotomy Orientation 321
Generation of the Initial Stem and Extraction 322
Final Adaptations 322
Stem Insertion and Resistance Simulation 322
The Design of the Extramedullary Section 322
The Prosthesis Validation 322
The Stem Manufacturing 322
Stem Machining 322
Materials and Coatings 324
Sterilization and Packaging 324
The Twenty-Years Clinical Use of Individual Cad for Cementless Hip Arthroplasty 324
The Rationale for the Use of Custom CAD for Hip Arthroplasty 324
The Authors’ Indications for Custom CAD in Cementless Hip Arthroplasty 325
The Clinical Results of Computer Assisted Designed Stems in THA 325
The Basis for Computer Assisted Hip Arthroplasty 326
Conclusion 327
References 327
28: Hip Resurfacing Guided by Fluoroscopy and Minimal Invasive Anterolateral Approach: Technique and Results 329
Targeting of the Pin-Guided Femoral Component Under Fluoroscopic Control 329
Which Particular Equipment Must Be Used? 329
Technique 329
Preparation 330
Targeting the Pin 330
Minimally Invasive Antero Lateral Approach for Hip Resurfacing: Technique 330
Preparation 330
Incision 330
Hip Approach 331
Capsule Dissection 331
Capsule Incision 332
Hip Dislocation 332
Acetabulum Preparation 332
Exposure of the Acetabulum 332
Reaming the Acetabulum 332
Acetabular Implantation 333
Exposure of the Femur 333
Femoral Preparation 334
Cylindrical Reaming of the Femoral Head 334
Leg Length Determination 334
Final Milling 334
Reduction and Closure 334
Postoperative 335
A Series of 129 Cases Between 2003 and 2009 335
Method 335
Discussion 336
Advantages and Disadvantages of the Use of a Guide Pin 336
Advantages 336
Disadvantages 337
Advantages and Risks of the Anterolateral Approach 337
Advantages 337
Disadvantages 337
Conclusion 338
References 338
29: Biomechanics of Osteosynthesis by Screwed Plates 339
Biological Aspects of Plate Fixation 339
Blood Supply of Cortical Bone 339
Vascular Disturbance Due to Trauma, Surgery, and Implant 339
Fracture Healing and Stability of Fixation 342
Mechanical Aspects of Plate Fixation 342
Basic Mechanical Principles of Internal Fixation 342
Plate Designs and New Plate Developments 343
Load Transfer in Conventional Plating 345
Load Transfer in Locked Screw Head Plating 347
Plate Fixation in Osteoporotic Bone 348
Mechanical Characteristics of Plates 349
Mechanics of Osteosynthesis Using Plates or Internal Fixators 350
Loading of the screw 350
Effect of Plate Length on Screw Loading 352
Effect of Screw Position on Plate Loading 353
Effect of Plate Position on Rigidity of Fixation 353
Effect of Plate Position and Plate Contouring on Plate Loading 355
Clinical Aspects of Plate Fixation 357
Plate Functions 357
Reduction Technique 361
Fixation Technique 363
Conclusions and Outlook 364
References 367
Part VI: Applications of Biomechanics Principles to Oncology 371
30: Malignant Bone Tumors: From Ewing’s Sarcoma to Osteosarcoma 372
Introduction 372
Epidemiology 372
Frequency 372
Risk Factors 373
Osteosarcoma 373
Ewing’s Sarcoma 373
Pathological Anatomy 373
Varieties 373
Osteosarcomas 373
Ewing’s Sarcoma 373
Spread 374
Osteosarcomas 374
Ewing’s Sarcoma 374
Diagnosis 374
Circumstances in Which It Is Discovered 374
The Components Involved in the Diagnosis 375
History-Taking and Clinical Examination 375
Biology 375
Radiological Examinations 375
Pathological Anatomy 375
Differential Diagnosis 376
Pre-therapeutic Inventory 376
Inventory 376
Loco-Regional 376
Metastatic Spread 376
Classification 376
Treatment 377
Method 377
Surgery 377
Radical Surgery 377
Conservative Surgery 377
Radiotherapy 377
Chemotherapy 377
Osteosarcoma 377
Ewing’s Sarcoma 378
Indications 378
Osteosarcomas 378
Special Case 378
Ewing’s Sarcoma 378
Course and Monitoring 379
Osteosarcoma 379
Ewing’s Sarcoma 379
Conclusion 379
Therapeutic Orientation in Osteogenic Sarcomas 379
Part VII: Articular Biomechanics 381
31: The Biomechanics of the Glenohumeral Articulation and Implications for Prosthetic Design 382
Introduction 382
Basic Biomechanical Principles 383
Glenohumeral Force and Joint Stability 384
Constraint and Conformity of the Glenoid Surface 385
Forces in the Abducted Shoulder 386
Anterior–Posterior Considerations 389
The Effect of Joint Friction 389
Implications for Shoulder Prosthesis Design 390
Summary 391
References 391
32: Robotic Surgery of the Scapulo-­Clavicular Girdle 393
Experimental Surgery 394
Clinical Experience 397
Conclusion 398
References 398
33: Pedicle Screw Fixation in Thoracic or Thoracolumbar Burst Fractures 399
Anatomy and Biomechanics 399
Pedicle Anatomy 399
Biomechanics 400
Pedicle Screw Diameter 400
Screw Length 400
Screw Direction 403
Screw Hole Preparations 403
Number of Screws 403
Transverse Links 403
Methods of Increasing the Stiffness of the Pedicle Screw Construct 403
Treatment Considerations and Indications 404
Posterior Pedicle Screw Fixation 404
Posterior Pedicle Screw Fixation with an Anterior Column Reconstruction 405
Surgical Techniques 411
Presurgical Considerations 411
Anesthesia 411
Intraoperative Monitoring 411
Positioning 411
Fusion/lnstrumentation Extent 411
Choice of Implants 413
Posterior Pedicle Screw Fixation 414
Incision and Exposure 414
Pedicle Screw Insertion 415
Rod Insertion 417
Ligamentotaxis 417
Posterior Pedicle Screw Fixation with Anterior Column Reconstruction 418
Posterior Pedicle Screw Fixation with Anterior Decompression/Stabilization 418
Posterior Pedicle Screw Fixation with Transpedicular Bone Graft 418
Posterior Pedicle Screw Fixation with Corpectomy/Anterior Column Reconstruction via the Posterior Approach (Posterior Vertebral Column Resection) 418
Posterior Pedicle Screw Fixation with Augmentation Vertebroplasty 420
Aftertreatment 420
Complications 420
References 420
34: Efficacy and Safety of an Absorbable Cervical Cage with and Without Plating: A Multicenter Case Study 422
Methods 422
Participants 422
Surgical Technique 423
Procedures 423
Statistical Analysis 424
Results 424
Radiological Results and Adverse Events 424
Clinical Outcome 426
Discussion 426
References 427
35: Biomechanics of Posterior Instrumentation for Spinal Arthrodesis 429
Implant Characteristics 429
Materials 429
Design 430
Anchoring Members 430
Longitudinal Members 435
Component-Component Connecting Mechanism 437
Transverse Members 437
Classification of Posterior Instrumentation 438
Posterior Distraction Instrumentation 438
Simple Distraction Construct 438
Fixed Moment Arm Cantilever Beam Fixation Construct 438
Applied Moment Arm Cantilever Beam Fixation Construct 439
Posterior Compression Instrumentation 439
Simple Posterior Compression Construct 439
Fixed Moment Arm Cantilever Beam Construct 440
Non-fixed Moment Arm Cantilever Beam Construct 440
Posterior Three-Point Bending Instrumentation 440
Posterior Distraction Construct 440
Cantilever Beam Constructs 441
Posterior Translation Instrumentation 441
Dynamic Translation Construct 441
Rigid Translation Construct 441
Clinical Applications 442
Fractures and Dislocations 442
Degree of Anterior Column Destruction 442
Translational Deformity 442
Degenerative Diseases 444
Deformities 444
Scoliosis 444
Kyphosis 449
Spondylolisthesis 453
Tumors 453
References 459
36: Biomechanics of Sacral Fixation 460
Anatomic Considerations of Sacral Fixation 460
Bone Mineral Considerations of the Sacral Fixation 461
Biomechanical Considerations of the Sacral Fixation 464
Strengths of Varieties of Fixations 464
Loosening of Sacral Screw Fixation Under Fatigue Loading 465
References 468
37: Current State of Management for Osteoporosis and Orthopaedic Related Spinal Problems 471
Therapeutic Management of Osteoporosis 471
Biological Basis 471
Therapeutic Management 472
Osteoprosis and the Spine 474
Osteoporosis and Intervertebral Discs 475
Clinical Implications 476
Treatment of Osteoporotic Fracture in the Spine 476
Indications 477
Technique of Vertebroplasty/Kyphoplasty 477
Outcome of Vertebroplasty/Kyphoplasty 477
Complications of Vertebroplasty/Kyphoplasty 478
Selection Between Vertebroplasty and Kyphoplasty 478
A Correct Attitude on Vertebral Augmentation 478
Conclusion 479
References 480
38: Optimised Treatment of Hip Fractures 482
The Future Problem 482
Fracture Types 482
Cervical Fractures 484
Undisplaced Cervical Fractures 484
Displaced Cervical Fractures 484
Timing of Operation 486
Practical Considerations at Operation 486
Positioning of Two Hook Pins or Screws 488
Considerations at Arthroplasty 489
Trochanteric Fractures 490
Subtrochanteric Fractures 491
Weightbearing and Rehabilitation 492
Hip Fracture Audit 492
References 494
39: Three-Dimensional Biomechanical Assessment of Knee Ligament Ruptures 497
Recording 3D Knee Kinematics 498
Marker Attachment 498
Skin Mounted Marker Optimization 498
Percutaneous Fixation 498
External Attachment Systems 499
Movement Representation 500
Euler Angles Versus Helical Axis Definition 500
Anatomical Coordinate Systems 501
Inter- and Intra-tester Variability 502
Gait Analysis 502
Gait Biomechanics 502
Kinematics 502
Kinetics 502
ACL-Deficient Gait 503
Quadriceps Avoidance Gait 504
Hamstring Facilitation Strategy 505
Biomechanical Deficiencies Associated with the Role of the ACL 505
Analysis of the Pivot Shift Phenomenon 506
Clinical Examination 507
Recording the Pivot Shift 508
Kinematics of the Pivot Shift 508
General Discussion 511
References 512
40: Knee Ligamentoplasty: Prosthetic Ligament or Ligament Allograft? 516
General Biomechanics 516
Basic Properties 516
The Parameters 516
Measuring Methods 516
Mechanical Properties of the Human Anterior Cruciate Ligament and of Prosthetic Ligaments 517
The Life of a Ligament 517
Biocompatibility and Rehabilitation 517
Biocompatibility 517
The Risks 517
The Tests 517
Rehabilitation of the Artificial Ligament 518
The Ligaments Used 518
Artificial Ligaments 518
Carbon 518
Polyethylene 518
Polypropylene 519
Polytetrafluoroethylene 519
Dacron 519
Tendon Allografts 519
Different Allografts Which Can Be Used 520
Preservation by Cryogenics Seems 520
Tolerance in the Host Subject 520
Mechanical Studies 520
Conclusion 520
Index 522