Imaging of Orthopedic Sports Injuries (Medical Radiology)

This book, now in a revised and updated second edition, provides a review of imaging abnormalities in orthopedic sports injuries. The first part of the book includes background information on relevant basic science and general imaging principles in sports traumatology, while the second part discusses the topography of various sports injuries. Each chapter highlights the merits of different imaging techniques, focusing on a specific clinical problem. The third part then examines natural history and monitoring. Several new chapters have been added, including a chapter on postoperative joint imaging in the sports patient as well as image-guided interventions in sports injuries. This well-illustrated book written by leading experts is a valuable resource for musculoskeletal as well as general radiologists, orthopedic surgeons, sports physicians, physiotherapists and anyone else involved in sports medicine. Foreword to the Second Edition Preface to the Second Edition Introduction Endorsement on Behalf of the European Society of Musculoskeletal Radiology (ESSR) Contents Part I: Relevant Basic Science and General Imaging Principles The Clinician’s Point of View 1 Introduction 2 Role of Imaging 3 What Is Expected from the Radiologist? 4 What Is Expected from the Radiology Department? 5 What Is Expected from the Sports Physician? 6 Risks of Over-Imaging 7 The Travelling Athlete 8 Conclusions References Imaging Techniques and Procedures in Sports Injuries 1 Introduction 2 Plain Radiography and Conventional Arthrography 2.1 Plain Radiography 2.2 Conventional Arthrography 3 Ultrasound 4 Computed Tomography 4.1 Multi-Detector CT 4.2 Dual-Energy CT 4.3 Cone Beam CT 4.4 CT Arthrography 5 Magnetic Resonance Imaging 5.1 Field Strength and Imaging Planes 5.1.1 Field Strength 5.1.2 Imaging Planes 5.2 MRI Sequences 5.3 Fat Suppression 5.4 Contrast Administration 5.5 Artefacts 5.6 Disadvantages 5.7 Direct and Indirect Arthrography 5.7.1 Direct Technique 5.7.2 Indirect Technique 6 General Principles and Indications 7 Optimal Moment of Investigation 8 Safety, Availability and Economic Aspects 9 Conclusion References Muscle Injuries 1 Introduction 2 Anatomy, Ultrastructure and (Patho)Physiology with Imaging Correlation 3 Muscle Trauma with Discussion of Grading Systems 3.1 Acute Traumatic Muscle Injuries 3.1.1 Muscle Elongation Trauma 3.1.1.1 Biomechanical Basis BAC Grade 0, Munich Type 1a BAC Grade 1, Munich Grade 3a BAC Grade 2 and 3, Munich Type 3b BAC Grade 4 or Munich Type 4 3.1.1.2 Clinical Presentation 3.1.1.3 Imaging BAC Grade 0, Munich Type 1 and Type 3a BAC Grade 1 Suffix a and b/Munich Type 3b BAC Grade 2, Suffix a, b or c/ Munich Type 3b BAC Grade 3, Suffix a, b or c/ Munich Type 3b BAC Grade 4/Munich Type 4 3.1.2 Crush Trauma 3.1.2.1 Muscle Contusion 3.1.2.2 Muscle Haematoma 3.1.2.3 Morel Lavallée Effusions/Closed Deglovements 3.2 Complications of Muscle Injury 4 Ultrasound-Guided Aspiration of Traumatic Collections 5 Delayed Onset Muscular Soreness (DOMS) 6 Chronic Exertional Compartment Syndrome 6.1 Definition, Clinical Presentation and Diagnosis 6.2 Imaging 7 Muscle Atrophy 8 Rhabdomyolysis 9 Calcific Myonecrosis 10 Muscle Herniation 11 Conclusion References Cartilage Trauma 1 Basic Science 1.1 Composition, Organization and Function of Normal Articular Cartilage 1.1.1 Introduction 1.1.2 The Structure of Articular Cartilage 1.1.3 Function of Cartilage 1.2 Composition and Function of Fibrocartilage 1.3 Mechanical Injury of Articular Cartilage: Mechanisms and Staging 1.3.1 Introduction 1.3.2 Mechanism of Injury 1.3.3 Staging of Cartilage Lesions 2 Imaging 2.1 Imaging Articular Cartilage 2.1.1 Conventional Radiography and Arthrography 2.1.2 CT Arthrography 2.1.3 Morphologic MR Imaging of Cartilage 2.1.4 Physiologic Imaging of Articular Cartilage 2.1.4.1 dGEMRIC 2.1.4.2 T2 Mapping and T2* Mapping 2.1.4.3 T1ρ Mapping 2.1.4.4 Diffusion-Weighted and Diffusion Tensor Imaging 2.1.4.5 Sodium Imaging 2.1.4.6 Magnetization Transfer Contrast/gagCEST 2.1.4.7 Ultrashort Echo Time Imaging 2.1.5 MR Arthrography 2.2 Imaging of Cartilage Trauma 2.2.1 Chondral Defects 2.2.2 Osteochondritis Dissecans and Osteochondral Lesions 2.3 Modalities for Cartilage Repair 2.4 Imaging Cartilage Repair 2.5 Scoring of Cartilage Repair 3 Conclusion References Basic Imaging Principles of Tendons and Ligaments 1 Introduction 1.1 Tendons 1.2 Ligaments 2 Imaging of Tendons and Ligaments 2.1 Ultrasound Imaging 2.2 Magnetic Resonance Imaging (MRI) 2.3 Radiographs and CT 3 Conclusion References Bone Marrow Edema in Sports Injuries/General Concept 1 Introduction 2 Definition and Classification 3 Pathogenesis of Bone Marrow Edema in Sports Injuries 3.1 Acute Traumatic Lesions 3.1.1 Impaction Injuries 3.1.2 Avulsive Injuries 3.1.3 Complex Patterns 3.2 Chronic Traumatic Lesions (Repetitive Trauma) 3.2.1 Fatigue Fractures 3.2.2 Chronic Avulsive Injuries 3.2.3 Altered Biomechanics and BME 3.3 Lesions of Unknown Pathogenesis 3.3.1 Bone Marrow Edema Syndrome 3.3.2 Bone Marrow Edema in Long-Distance Runners 3.3.3 Subchondral Insufficiency Fracture 4 Histopathological Correlation 5 Clinical Significance 6 Natural Evolution 6.1 Follow-Up of Acute Traumatic Bone Marrow Edema 6.2 Follow-Up of Chronic Traumatic Lesions 6.3 Follow-Up of BMES 7 Conclusion References Overuse Bone Trauma and Stress Fractures 1 Introduction 2 Pathophysiology 2.1 Bone Anatomy 2.1.1 Macroscopic Anatomy 2.1.2 Microscopic Anatomy 2.2 Bone Remodeling 3 Mechanisms of Injury 3.1 High-Risk Versus Low-Risk Stress Fractures 4 Risk Factors 4.1 Intrinsic Risk Factors 4.1.1 Bone Mineral Density 4.1.2 Female Sex 4.1.3 Age 4.1.4 Lower Extremity Biomechanics 4.1.4.1 Pronated Foot 4.1.4.2 Cavus Foot 4.1.4.3 Varus Alignment 4.1.4.4 Limb Length Discrepancy 4.2 Extrinsic Risk Factors 5 Diagnostic Imaging 5.1 Conventional Radiography 5.2 Bone Scintigraphy and SPECT-CT 5.3 Conventional CT and Dual-Energy CT 5.4 Ultrasound 5.5 MRI References Pseudotumors in Sports 1 Introduction 2 General Imaging Principles 3 Keys to Differential Diagnosis and True Tumors 4 Soft Tissue-Related Pseudotumors 4.1 Muscle Tear, Morel-Lavallée Syndrome, and Rhabdomyolysis 4.1.1 Hematoma 4.1.2 Morel-Lavallée Syndrome 4.1.3 Myocele/Hernia 4.1.4 Rhabdomyolysis 4.1.5 Calcific Myonecrosis 4.2 Overuse and Tear of Ligaments and Tendons 4.3 Nodular Fasciitis (Pseudosarcomatous Fasciitis) 4.4 Myositis Ossificans and Nora Lesion (BPOP) 4.4.1 Myositis Ossificans 4.4.2 Nora Lesion (Bizarre Parosteal Osteochondromatous Proliferation/BPOP) 4.5 Inflammatory Myopathies 4.6 Muscle Denervation 4.7 Stress Reactions in Soft Tissue 5 Bone-Related Pseudotumors 5.1 Fractures, Occult Fractures, and Stress Reactions 5.2 Avascular Necrosis 5.3 Rheumatological or Degenerative Joint Disease 6 Normal Variants 7 Infection 8 Calcium Deposition Disorders 9 Metabolic Disorders 10 Foreign-Body Reactions 11 Vascular Pseudoaneurysms 12 Posttreatment/Intervention (Steroid-Induced Osteoporosis, Insufficiency Fracture) References Part II: Topographic Discussion Shoulder Instability 1 Introduction: Epidemiology—Classification 2 Relevant Anatomy: Variants—Biomechanics 3 Traumatic Anterior Instability 3.1 Imaging in Shoulder Instability 3.2 Soft-Tissue Lesions 3.2.1 Bankart Lesion 3.2.2 Perthes Lesion 3.2.3 ALPSA Lesion 3.2.4 HAGL Lesion 3.2.5 GLAD Lesion 3.2.6 SLAP Lesion 3.3 Osseous Lesions 3.3.1 Glenoid Bone Loss (GBL) 3.3.2 Hill-Sachs Impression 3.3.3 On-Track/Off-Track Concept in Bipolar Bone Lesions 3.4 Postoperative Imaging 4 Traumatic Posterior Instability 5 Microtraumatic Instability and Internal Impingement 5.1 Glenohumeral Internal Rotational Deficit (GIRD) 5.2 Posterosuperior Impingement (PSI) 5.3 Anterosuperior Impingement 6 Hyperlaxity: Atraumatic Instability References Rotator Cuff and Impingement Symptoms 1 Introduction 2 MR Imaging Technique 3 Ultrasonography: Normal Appearance of the Shoulder 4 Shoulder Impingement Syndrome 4.1 Primary Extrinsic Impingement 4.2 Secondary Extrinsic Impingement 4.3 Internal Impingement 4.4 Coracohumeral Impingement 5 MR Imaging and Rotator Cuff Injuries 6 Ultrasonography and Rotator Cuff Injuries 7 Rotator Interval and Biceps Tendon Injuries 8 Miscellaneous Conditions That May Mimic Rotator Cuff Pathology 9 Conclusion References Scapular, Clavicular, Acromioclavicular, and Sternoclavicular Joint Injuries 1 Introduction 1.1 Scapula 1.2 Clavicle 1.3 Acromioclavicular Joint 1.4 Sternoclavicular Joint 2 Imaging 2.1 Plain Radiography 2.1.1 Scapula 2.1.2 Clavicle 2.1.3 AC Joint 2.1.4 SC Joint 2.2 Ultrasound 2.2.1 AC Joint 2.2.2 SC Joint 2.3 CT 2.3.1 Scapula and Clavicle 2.3.2 SC Joint 2.4 MRI 2.4.1 AC Joint 2.4.2 SC Joint 2.5 Scintigraphy 3 Specific Overuse Trauma 3.1 Scapula 3.1.1 Fractures 3.1.2 Lateral Acromial Apophysitis 3.1.3 Stress-Related Growth Plate Injury of the Coracoid Process 3.1.4 Stress Fractures 3.1.5 Suprascapular Nerve Entrapment (SSNE) 3.1.6 Long Thoracic Neuropathy 3.2 Clavicle 3.2.1 Fractures 3.2.2 Distal Clavicular Osteolysis (DCO) 3.2.3 Stress Fractures 3.2.4 Stress-Related Growth Plate Injury of the Proximal Clavicle 3.3 AC Joint 3.3.1 Sprain/Dislocation 3.3.1.1 Plain Film Analysis Zanca View Unilateral Versus Bilateral Weighted Views Unilateral Versus Bilateral Type 4 Lesion 3.3.2 Osteoarthritis (OA) 3.4 SC Joint 3.4.1 Sprain/Dislocation References Imaging of Sports Injuries of the Elbow 1 Introduction 2 Anatomy 3 Biomechanics 3.1 Introduction 3.2 Baseball (and Other Overhead Throwing Sports) 3.3 Golf 3.4 Tennis 3.5 Handball and Soccer (European Football) 3.6 Gymnastics 4 Imaging the Elbow 4.1 Introduction 4.2 Baseball and Overhead Throwing Sports 4.2.1 Standard Radiographs 4.2.2 Ultrasound 4.2.3 MRI 4.2.4 CT 4.3 Golf 4.3.1 Standard Radiography 4.3.2 Ultrasound 4.3.3 MRI 4.4 Tennis 4.4.1 Standard Radiography 4.4.2 Ultrasound 4.4.3 MRI 4.5 Handball and Soccer 4.5.1 Standard Radiography 4.5.2 Ultrasound 4.5.3 MRI 4.5.4 CT 4.6 Gymnastics 4.6.1 Standard Radiography 4.6.2 Ultrasound 4.6.3 MRI 4.6.4 CT 5 Conclusions References Imaging of Wrist Injuries 1 Introduction 2 Sports Injuries in Children 3 Anatomy 4 Biomechanics of Sports Injuries 4.1 Overview 4.2 Fractures 4.2.1 Radial Fractures 4.2.2 Scaphoid Fractures 4.2.3 Hamate Fractures 4.2.4 Lunate Fracture 4.3 Wrist Instability 4.4 Post-traumatic Deformity Patterns 4.5 TFCC Injuries 4.6 Tendon Injuries 4.7 Neurovascular Injuries 5 Specific Types of Sports Injuries 5.1 Golf, Baseball, and Racquet Sports 5.2 Gymnastics 5.3 Rowing/Canoeing, Volleyball, and Basketball 5.4 Cycling/Wheelchair Athletes 5.5 American Football, Horse Riding/Rodeo, Roller-Skating/Rollerblading/Skateboarding/Hoverboarding 5.5.1 American Football 5.5.2 Horse Riding/Rodeo 5.5.3 Roller-Skating/Rollerblading/Skateboarding/Hoverboarding 5.6 Snowboarding and Skiing 6 Conclusion References Finger and Hand 1 Introduction and Technical Considerations 2 Extensor Tendon Rupture 3 Dorsal Hood Rupture 4 Flexor Tendon Rupture 5 Annular Pulley Rupture 6 Volar Plate and Collateral Ligament Injury 7 Ulnar Collateral Ligament of the Thumb 8 De Quervain Tendons 9 Other Sport-Related Injuries of the Hand 10 Conclusion References Athletic Groin Pain 1 Introduction 2 Overview of Regional Anatomy 2.1 Pubic Symphysis 2.2 Muscles/Aponeurosis 2.3 Inguinal Canal 2.4 Iliopsoas Muscle 3 Overview of Imaging in Groin Pain 3.1 Ultrasound Protocol 3.2 MRI Protocol 4 Acute Groin Pain 4.1 Overview 4.2 Acute Groin Injury: Muscle-Related Injuries 4.2.1 Acute Hip Adductor Muscle Injury 4.2.1.1 Anatomy and Mechanism of Acute Adductor Longus Injuries 4.2.1.2 Acute Adductor Muscle Injury Pattern At the Proximal Insertion into the Capsule and Anterior Pubic Body At the Proximal Myotendinous Junction At the Distal Myotendinous Junction 4.2.1.3 Other Adductor Muscle Injuries 4.2.2 Acute Hip Flexor and Rotator Muscle Injury 4.2.2.1 Iliacus and Iliopsoas Injury 4.3 Correlation Between Clinical Examination and MR Findings in Acute Muscle Injuries 4.4 Acute Groin Injury: Bone-Related Injuries 4.4.1 Pubic Apophysitis and Avulsion Fractures 4.4.1.1 Apophyseal Anatomy 4.4.1.2 Diagnosis 4.4.1.3 Management 4.4.2 Pubic Stress Fractures 4.5 Management and Prevention of Acute Groin Injuries 5 Long-Standing Groin Pain 5.1 Overview 5.2 Adductor-Related Groin Pain 5.2.1 Pathophysiology 5.2.2 Clinical Findings 5.2.3 Imaging Findings 5.2.3.1 Pathological Changes at the Common Adductor-Capsule-Rectus Abdominis Aponeurosis 5.2.3.2 Pubic Bone Marrow Oedema 5.3 Pubic-Related Groin Pain 5.3.1 Pathophysiology 5.3.2 Clinical Findings 5.3.3 Imaging Findings 5.4 Inguinal Related Groin Pain 5.4.1 Pathophysiology 5.4.1.1 Anterior Inguinal Wall Deficiency 5.4.1.2 Posterior Inguinal Wall Deficiency 5.4.2 Clinical Findings 5.4.3 Imaging Findings 5.5 Iliopsoas-Related Groin Pain 5.5.1 Clinical Findings 5.5.2 Imaging Findings 5.6 Overview of Treatment of Long-Standing Groin Pain 5.6.1 Adductor Strengthening in Groin Injury Prevention Programme 6 Summary References Hip, Pelvis and Sacro-Iliac Joints 1 Introduction 2 Aetiology, Diagnosis and Prognosis of Hip and Groin Pain 3 Anatomy 3.1 Hip and Pelvis Morphology 3.1.1 Structural Layer 3.1.2 Capsulo-ligamentous Layer (Fig. 2) 3.1.3 Muscular Layer 3.1.4 Neuromechanical Layer 3.1.5 Vascular Anatomy of the Hip 4 Imaging Techniques 4.1 Radiographs 4.1.1 General Technical Considerations 4.1.2 Views and Basic Technique (Table 5) 4.1.3 Parameters 4.2 Ultrasound 4.3 Computed Tomography 4.4 Magnetic Resonance Imaging 5 Pathology 5.1 Hip Intra-articular 5.1.1 Acetabular Dysplasia and Instability (Fig. 9) 5.1.2 Ligamentum Teres Pathology 5.1.3 Femoroacetabular Impingement 5.1.3.1 Cam Mechanism 5.1.3.2 Pincer Mechanism 5.1.3.3 Diagnosis (Fig. 12) 5.1.3.4 Association Between FAIS and Sport Activities 5.1.4 Labrum Pathology 5.1.4.1 Anatomy and Imaging Description 5.1.4.2 Normal Variants (Fig. 13) 5.1.4.3 Labral Tears (Fig. 14) 5.1.5 Cartilage Pathology 5.1.5.1 Anatomy and Imaging Description 5.1.5.2 Normal Variants (Fig. 15) 5.1.5.3 Cartilage Injury 5.1.6 Hip Osteoarthritis 5.2 Hip Peri-articular Pathology 5.2.1 Greater Trochanteric Pain Syndrome 5.2.2 Snapping Hip 5.2.3 Extra-articular Hip Impingement Syndromes 5.2.3.1 Deep Gluteal Pain Syndrome (and Piriformis Syndrome) 5.2.3.2 Ischiofemoral Impingement 5.2.3.3 Subspine Impingement 5.3 Pelvis 5.3.1 Stress Fractures 5.3.2 Muscles, tendons and enthesis 5.3.2.1 Apophyseal Injuries 5.3.2.2 Muscle and Tendon Injuries Hamstring Injuries Proximal Rectus Femoris Injuries Iliopsoas Injuries Proximal Iliotibial Band Syndrome Adductor Insertion Avulsion Syndrome 5.3.2.3 Nerves and Nerve Entrapment Syndromes 5.4 Sacroiliac Joints 5.4.1 General Considerations 5.4.2 Mechanical/Degenerative Changes of the SIJ: Athletes 5.4.3 Mechanical/Degenerative Changes of the SIJs: Non-athletes 5.4.4 Differential Diagnosis 6 Future Trends in Hip Imaging 6.1 Artificial Intelligence 6.2 Personalized Medicine and Biobanks 7 Conclusion References Sports-Related Meniscal Injury 1 Introduction 2 Anatomy and Function 3 Epidemiology of Meniscal Injuries 4 Imaging of the Meniscus 4.1 Plain Radiography and Conventional Arthrography 4.2 Ultrasound 4.3 Magnetic Resonance Imaging 4.3.1 Technique 4.3.2 MRA 4.3.3 Normal MR Anatomy 4.3.4 Diagnosis of Meniscal Tears 4.3.5 Classification of Meniscal Tears 4.3.6 Accuracy and Limitations of MRI 4.3.6.1 Unavoidable Errors 4.3.6.2 Equivocal Errors 4.3.6.3 Interpretation Errors 4.4 CT Arthrography 5 Therapeutic Management in Athletes 5.1 Conservative Treatment 5.2 Surgical Interventions 5.2.1 Meniscectomy (Partial-Complete) 5.2.2 Meniscus Repair 5.2.3 Meniscus Reconstruction 6 Imaging of the Post-operative Meniscus 6.1 MR Appearance After (Partial) Meniscectomy 6.2 MR Appearance After Meniscus Repair 6.3 MR Appearance After Meniscal Replacement 6.4 Conventional MR Versus MRA Versus CTA in the Post-operative Meniscus 6.4.1 Imaging Pathway in the Post-operative Meniscus 7 Specific Sports and Overuse Trauma of the Meniscus 7.1 Injury Mechanisms in Sports Injury 7.2 Symptomatic and Asymptomatic Meniscal Lesions in Athletes 8 Conclusion 9 Imaging Boxes References Knee: Ligaments and Tendons 1 Introduction 2 Intra-articular Ligaments 2.1 The Anterior Cruciate 2.1.1 Anatomy 2.1.2 Imaging 2.1.3 Injuries to the Anterior Cruciate 2.1.3.1 Primary Signs of ACL Rupture 2.1.3.2 Secondary Signs Secondary Signs: Bone Injury Secondary Signs: Soft Tissue Secondary Signs: Anterior Tibial Translation 2.1.3.3 Partial ACL Rupture 2.1.4 Associated Injuries 2.1.5 Ganglion Cyst of the Cruciate Ligament 2.2 Posterior Cruciate Ligament 2.2.1 Anatomy 2.2.2 Imaging 2.2.3 Posterior Cruciate Ligament Injury 2.3 Minor Intracapsular Ligaments 2.3.1 Intermeniscal Ligaments 2.3.2 The Meniscofemoral Ligament 2.3.3 Miscellaneous Intra-articular Minor Ligaments 3 Extra-articular Ligaments and Tendons 3.1 The Lateral Stabilisers 3.1.1 The Iliotibial Band 3.1.2 Posterolateral Corner 3.1.2.1 Fibular Collateral Ligament Injury 3.1.2.2 Biceps Femoris Injuries 3.1.2.3 Popliteus Complex Injuries 3.1.2.4 Capsule and Capsular Ligaments 3.1.3 Anterolateral Ligament Injury 3.1.4 Lateral Compartment Ganglia 3.2 The Medial Stabilisers 3.2.1 The Medial Collateral Ligament 3.2.2 The Posteromedial Corner 3.2.3 Medial Compartment Ganglia 4 Dislocation 5 Conclusion References Imaging of Anterior Knee Pain and Maltracking 1 Introduction 2 Acute Trauma to the Extensor Mechanism 2.1 Patellar Dislocation 2.2 Patellar Tendon Rupture 2.3 Quadriceps Tendon Rupture 2.4 Prepatellar Bursa 2.5 Fractures 3 Anterior Knee Pain Without Acute Trauma 3.1 Disorders of the Patellar Tendon 3.2 Medial Patellar Plica 3.3 Hoffa’s Fat Pad 3.4 Patellofemoral Joint 3.4.1 Patellofemoral Pain Syndrome 3.4.2 Bipartite Patella 3.4.3 Osteochondritis Dissecans 3.4.4 Patellar Maltracking 4 Conclusion References Injuries of the Ligaments and Tendons in Ankle and Foot 1 Ankle Ligament Tears 1.1 Lateral Ligament Complex 1.2 Distal Syndesmotic Tibiofibular Complex 1.3 Deltoid Ligament Complex 1.4 Subtalar Ligaments 1.5 Spring Ligament 2 Midfoot Ligament Injuries 2.1 Chopart Joint Ligaments 2.2 Lisfranc Ligament Injuries 3 Forefoot Ligament Tears 3.1 First Metatarsophalangeal Joint Ligaments 4 Tendon Disorders 4.1 Lateral Tendons: Peroneal Tendons 4.1.1 Peroneal Tendinosis, Tendinopathy and Tenosynovitis 4.1.2 Peroneal Tendon Tears 4.1.3 Anatomical Muscle and Osseous Variants and Pitfalls 4.1.4 Peroneal Retinaculum Injuries and Tendon Dislocation 4.2 Medial Flexor Tendons 4.2.1 Posterior Tibial Tendon Dysfunction 4.2.2 Flexor Retinaculum Injuries and Dislocation of PTT 4.2.3 Accessory Navicular Syndrome and PTT Injuries 4.2.4 Flexor Hallucis Longus Disorders 4.3 Anterior Extensor Tendons 4.3.1 Anterior Tibial Tendon Injuries 4.3.2 Extensor Hallucis Longus, Digitorum Longus and Peroneus Tertius Tendon Injuries 4.4 Plantar Fascia 4.4.1 Plantar Fasciitis 4.4.2 Plantar Fascia Tear 4.5 Achilles Tendon 4.5.1 Achilles Tendinopathy 4.5.2 Achilles Tendon Rupture 4.6 Plantaris Tendon References Ankle and Foot: Osteochondral Injuries 1 Introduction: Specific Anatomy and Incidence 1.1 Cartilage Anatomy 2 Historical Background and Terminology 3 Incidence 4 Etiology 4.1 Biomechanical Etiology 4.2 Biological Etiology 5 Pathophysiology 6 Location of Osteochondral Defects 7 Diagnostic Imaging 7.1 Conventional Radiography 7.1.1 Hardware and Positioning 7.1.2 Scan Protocol and Post-processing 7.1.2.1 AP View 7.1.2.2 Mortise View 7.1.2.3 Lateral View 7.1.3 Conventional Radiography of an OCD 7.2 Computed Tomography 7.2.1 Hardware and Positioning Multi-Helical Systems 7.2.2 Hardware Dual-Energy Systems 7.2.3 Scan Protocol and Post-processing Software Multi-Helical Systems 7.2.4 Scan Protocol and Post-processing Software Dual-Energy Systems 7.2.5 CT Imaging of an OCD 7.3 Single-Photon Emission Computed Tomography 7.3.1 Hardware and Positioning 7.3.2 Scan Protocol and Post-processing Software 7.3.3 SPECT-CT of an OCD 7.4 Magnetic Resonance Imaging 7.4.1 Hardware and Positioning 7.4.2 Scan Protocol and Post-processing Software 7.4.3 MR Imaging of an OCD 7.5 Imaging ACR Appropriateness Criteria 8 Imaging Assessment 8.1 Alignment 8.2 Morphology 8.3 Location 8.4 Size 8.5 Bone Marrow Edema (BME) 8.6 Staging 9 Pitfalls in Imaging 10 Osseous Injury 10.1 Snowboarder’s Fracture 11 The Foot 11.1 Osteochondral Injuries 11.2 Skimboarder’s Toe 12 Overuse Injury of the Foot 12.1 Navicular Stress Fracture 12.2 Sesamoid Overuse Injury References Acute and Overuse Lesions of the Leg and Calf 1 Introduction 2 Acute Osseous Injury 2.1 Imaging Strategy and Management 3 Chronic Exertional Leg Pain 3.1 Chronic Osseous Stress Response and Injury 3.1.1 Tibia and Fibula 3.2 Medial Tibial Stress Syndrome (MTSS) 3.2.1 Imaging and Management of Osseous Stress Reaction 3.3 Chronic Exertional Compartment Syndrome (CECS) 3.3.1 Imaging 3.4 Vascular and Nerve Compression 3.4.1 Vascular 3.4.2 Imaging and Management 3.4.3 Nerve Compression 4 Acute Lower Limb Muscle Injury 4.1 Biomechanical Basis of Acute Lower Limb Muscle Injury 4.2 Imaging of Acute Lower Limb Muscle Injury 4.2.1 Hamstring Injuries 4.2.2 Quadriceps 4.2.3 Calf 4.3 Delayed-Onset Muscle Soreness 4.4 Muscle Contusion 4.4.1 Imaging 5 Complications of Lower Limb Muscle Injury 5.1 Fibrous Scarring 5.2 Myositis Ossificans 5.3 Muscle Atrophy/Hypertrophy/Hernia 5.4 Morel-Lavallée Lesion and Periosteal Haematoma 5.4.1 Morel-Lavallée Lesion 5.5 Periosteal Haematoma 6 Conclusion 7 Boxes References The Spine in Sports Injuries: The Cervical Spine 1 Introduction 2 Anatomical Considerations 3 Biomechanics of the Cervical Spine 4 Radiological Examination 5 Cervical Strain and Sprain 6 Burners and Stingers 7 Nerve Root and Plexus Avulsion 8 Cervical Disc Herniation 9 Transient Quadriparesis and Spinal Stenosis 10 Catastrophic Cervical Spine Injuries 11 Differential Diagnosis References The Spine in Sports Injuries: Thoracic and Lumbar Spine 1 Introduction 2 Indications 2.1 Trauma 2.2 Overuse 2.3 Osteoporosis 3 Image Interpretation 3.1 Imaging Findings 3.1.1 Trauma 3.1.2 Congenital and Developmental Disorders 3.1.3 Stress Reactions of the Bone and the Discovertebral Junction 3.1.4 Osseous Stress Reactions 3.1.5 Discovertebral Overuse 3.1.6 Degenerative Joint and Disc Disease 3.2 Differential Diagnosis 4 Conclusion References Sports-Related Maxillofacial Injuries 1 Introduction 2 Correlation Between Injury Type and Injury Mechanism Among Sports 2.1 Dentoalveolar Fractures 2.2 Facial Bone Fractures 3 Imaging Strategy 3.1 Plain Radiography 3.2 Multidetector Versus Cone Beam Computed Tomography (CT) 3.3 Magnetic Resonance (MR) Imaging 4 Specific Sports-Related Maxillofacial Injuries 4.1 Soft Tissue Injuries 4.2 Dentoalveolar Injuries 4.3 Mandibular Fractures 4.4 Central Midface Fractures 4.5 Lateral Midface Fractures 4.6 Frontal Sinus Fractures 5 Conclusions References Thoracic and Abdominal Wall Injuries in Sports 1 Introduction 2 Rib Cage and Thoracic Wall 2.1 Rib Fractures and Chondral Lesions 2.2 Stress Fractures of the Ribs 2.3 Injuries to the Sternum 2.4 Injuries to the Pectoralis Major, Latissimus Dorsi and Teres Major 2.5 Scapulothoracic Crepitus and Bursitis 3 Abdominal Wall 3.1 Introduction 3.2 Abdominal Wall Muscle Lesions 3.2.1 Side Strain and Hip Pointer 3.2.2 Rectus Abdominis Lesions 3.2.3 Iliopsoas Injury 3.2.4 Acute Groin Disruption 3.2.5 Groin Pain in Athletes 3.2.6 Imaging of Groin Pain 3.3 Traumatic Abdominal Wall Injury and Hernia in Children 3.4 Addendum: Endofibrosis of the Iliac Arteries 4 Conclusions 5 Referral Criteria 5.1 Boxes References Special Considerations in the Immature Skeleton 1 Introduction 2 Normal Variants Simulating Traumatic Lesions 3 Upper Limb 3.1 Shoulder 3.2 Elbow 3.3 Wrist and Hand 4 Spine 5 Pelvis 6 Lower Limb 6.1 Hip 6.2 Proximal Femur 6.3 Knee 6.4 Ankle and Foot References The Aging Athlete 1 Introduction 2 Impact of Osteoarthritis in Sport Activities: Risk and Consequences 3 Long-Term Joint Injuries 3.1 Lower Extremity: Knee 3.1.1 Knee: ACL 3.1.2 Knee: PCL 3.1.3 Knee: Meniscus Tears 3.1.4 Articular Cartilage/Subchondral Bone Injury 3.2 Lower Extremity: Hip 3.3 Lower Extremity: Ankle 3.4 Upper Extremity: Shoulder 3.5 Upper Extremity: Elbow 3.6 Upper Extremity: Wrist and Hands 4 Muscle, Ligament, Tendon 5 Bone Health 6 Sports After Total Joint Replacement 7 Sarcopenia 7.1 Epidemiology 7.2 Histology 7.3 Imaging Techniques 7.3.1 Muscle Mass 7.3.2 Muscle Quality 8 Conclusions References Part III: Monitoring of Sports Injury Repair Natural History and Monitoring of Fractures and Microfractures 1 Introduction 2 Fractures 2.1 Osseous Fractures 2.1.1 Natural History 2.1.2 Monitoring 2.2 Avulsion Fractures 2.2.1 Natural History 2.2.2 Monitoring 2.3 Osteochondral Lesions and Focal Osseous Indentations 2.3.1 Natural History 2.3.2 Monitoring 3 Microfractures 3.1 Stress Reactions and Fractures 3.1.1 Natural History and Monitoring 3.2 Acute Subchondral Injury: Bone Bruise 3.2.1 Natural History and Monitoring 3.3 Acute Occult Fractures 3.3.1 Natural History and Monitoring 3.4 Physeal Microfractures 3.4.1 Natural History 3.4.2 Monitoring 4 Deep Learning 5 Conclusions References Monitoring of Muscle and Tendon Repair 1 Introduction 2 Healing Process of Muscle and Tendon Injury 3 What the Radiologist Needs to Know 3.1 MR Protocol 3.2 What to Look for at Follow-Up 3.3 Advanced MR Techniques 3.3.1 T2 Mapping 3.3.2 Diffusion-Weighted/Diffusion Tensor Imaging 3.3.3 Spectroscopy 3.3.4 Ultrahigh-Field MRI 4 Conclusion: Outlook for the Future 5 Imaging Boxes References Part IV: Addenda Imaging-Guided Intervention of Sports Injuries 1 Basic Clinical Information 2 Contraindications, Complications, and Informed Consent 3 Patient Positioning 4 Antisepsis 5 Probe Selection 6 Interventional Equipment 7 Basic Principles of Ultrasound Guidance 8 Ultrasound-Guided Treatment of Traumatic Sports Injuries 8.1 Hematomas 8.2 Muscle Strain Injuries 8.2.1 Platelet-Rich Plasma (PRP) 9 Ultrasound-Guided Treatment of Nontraumatic Sports Injuries 9.1 Cysts and Articular Ganglia Drainage 9.2 Tendinopathies 9.2.1 Scarification of the Tendons (Dry Needling) 9.2.2 Regenerative Treatments 9.2.3 High-Volume Injection 9.2.4 Tendon Synovial Sheath Injection References Postoperative Imaging of Joints in the Sportive Patient 1 Postoperative Shoulder 1.1 Impingement and Rotator Cuff 1.1.1 Objective of Surgery 1.1.2 Surgical Procedure of Subacromial Decompression 1.1.3 Normal Postoperative Imaging Findings 1.1.4 Abnormal Postoperative Imaging Findings 1.1.5 Surgical Procedure of Rotator Cuff Repair 1.1.6 Normal Postoperative Findings 1.1.7 Abnormal Postoperative Imaging Findings 1.2 Shoulder Instability 1.2.1 Objective of Surgery 1.2.2 Surgical Procedure 1.2.3 Normal Imaging Findings 1.2.4 Abnormal Postoperative Imaging Findings 1.3 Long Head of the Biceps Tendon and SLAP Lesion 1.3.1 Objective of Surgery 1.3.2 Surgical Procedure 1.3.3 Normal Postoperative Findings 1.3.4 Abnormal Postoperative Findings 2 Postoperative Hip 2.1 Femoroacetabular Impingement Surgery 2.1.1 Objective of Surgery 2.1.2 Surgical Procedures 2.1.3 Normal Postoperative Findings 2.1.4 Abnormal Postoperative Findings Undercorrection Overcorrection Osteoarthritis Adhesions Avascular Necrosis of the Femoral Head, Heterotopic Ossification, and Iatrogenic Intra-articular Injuries 3 Postoperative Knee 3.1 Anterior Cruciate Ligament Reconstruction 3.1.1 Objective of Surgery 3.1.2 Surgical Procedures 3.1.3 Normal Postoperative Findings 3.1.4 Abnormal Postoperative Findings 3.2 Meniscus Repair 3.2.1 Objective of Surgery 3.2.2 Surgical Procedure of Meniscus Repair 3.2.3 Normal Postoperative Findings 3.2.4 Abnormal Postoperative Findings 3.3 Cartilage Repair 3.3.1 Objectives of Surgery 3.3.2 Surgical Procedure 3.3.3 Normal and Abnormal Imaging Findings References Imaging of Sports Lesions in Soccer Players 1 Introduction 2 Groin Injuries 2.1 Adductor-Related Groin Pain 2.2 Iliopsoas-Related Groin Pain 2.3 Inguinal-Related 2.4 Pubic-Related 3 Pelvis and Hip-Related Groin Pain 3.1 Femoroacetabular Impingement 3.2 Labral Tears 3.3 Stress Fractures 3.4 Ischiofemoral Impingement 3.5 Subspine Impingement 3.6 Snapping Hip 3.7 Apophysitis or Avulsion Fractures 3.7.1 Acute Avulsion Injuries 3.7.2 Chronic Traction Injuries/Apophysitis 4 Knee Injuries 4.1 Patellar Tendinopathy/Jumper’s Knee 4.2 Osgood-Schlatter Disease 4.3 Anterior Cruciate Ligament Tear 4.4 Meniscus Injury 4.5 Medial Collateral Ligament 5 Ankle Injuries 5.1 Ligament Injuries 5.2 Osteochondral Lesions 5.3 Impingement Syndromes 5.4 Calcaneal Apophysitis 5.5 Achilles Tendinopathy and Rupture 5.6 Turf Toe 6 Muscle Injuries References