1 Knee Injuries/1 Robert H. Miller III, Frederick M. Azar 2 Shoulder and Elbow Injuries/ 177 Robert H. Miller III, Frederick M. Azar, Thomas W. Throckmorton 3 Recurrent Dislocations /229 Barry B. Phillips 4 Traumatic Disorders/ 282 ANATOMY/ 2 Osseous structures /2 Extraarticular tendinous structures /2 Extraarticular ligamentous structures/ 4 Medial side anatomy/ 5 Posteromedial corner/ 5 Lateral side anatomy /7 Intraarticular structures /12 MECHANICS/ 13 MENISCI/ 14 Function and anatomy /14 Meniscal healing and repair /17 Mechanism of tear /18 Classification of meniscal tears/ 18 Diagnosis/ 19 Diagnostic tests /20 Imaging studies/ 21 Arthroscopy/ 21 Nonoperative management /21 Operative management/ 22 Other conditions of menisci /28 Cysts of menisci /28 Discoid meniscus /30 ACUTE TRAUMATIC LESIONS OF LIGAMENTS/ 31 General considerations/ 31 Etiology /31 Mechanism /31 Ligament healing /32 Classification /32 Diagnosis/ 32 History and physical examination /32 Radiographic examination /41 Classification of knee instability/42 One-plane instability/ 43 Rotary instability/ 44 Combined instabilities /44 Treatment considerations/ 44 Nonoperative treatment /44 Operative treatment /46 Medial compartment (collateral) disruptions/ 47 Repair/ 47 Reconstruction /55 Reconstruction with allograft tendons /61 Lateral compartment (collateral) disruptions/ 62 Reconstruction of lateral compartment /70 Posterolateral rotary instability /70 Posterolateral Instability with varus knee /82 Anterolateral rotary instability/ 85 ANTERIOR CRUCIATE LIGAMENT INJURIES/ 85 Incidence /85 Anatomy/ 85 Biomechanics /86 History and physical examination /86 Natural History/ 87 Treatment/ 89 Reconstruction for anterior cruciate ligament insufficiency /91 Rehabilitation after anterior cruciateligament reconstruction/ 108 Results of anterior cruciate ligament reconstruction /109 Complications of anterior cruciate ligament surgery /111 Revision anterior cruciate ligament surgery/ 112 Graft selection /113 Technical considerations/ 114 POSTERIOR CRUCIATE LIGAMENT /115 Anatomy /115 Biomechanics /116 Physical examination /116 Natural history/ 116 Treatment /117 Nonoperative treatment/ 117 Operative treatment /118 Arthroscopically aided posterior cruciate ligament reconstruction /130 Complications of posterior cruciate ligament reconstruction 131 TRAUMATIC DISLOCATIONS 131 Classification 131 Examination and radiographic evaluation 132 Vascular and nerve injuries /133 Vascular injuries /133 Nerve damage /134 Other associated injuries/ 134 treatment /134 Outcome of operative treatment of knee dislocations/ 137 SYNOVIAL PLICAE /138 ARTICULAR CARTILAGE INJURIES /139 Treatment /140 Arthroscopic debridement /140 Abrasion chondroplasty, microfracture/ 140 Osteochondral autograft transplant, osteochondral allografting, autologous chondrocyte implantation /141 Autologous chondrocyte implantation /142 Emerging technologies/ 146 OSTEOCHONDRITISDISSECANS/ 146 Etiology/ 147 Clinical and radiographic findings/ 147 treatment /148 Excision of loose bodies /149 Outcomes of treatment ofosteochondritis dissecansof the knee /150 Complications/ 150 DISORDERS OF THEPATELLA/ 150 Osteochondritis dissecansof the patella /150 Dorsal defect of the patella/ 150 Bipartite patella/ 151 Chondromalacia of the patella/ 152 Classification and etiology /153 Clinical findings/ 153 Treatment/ 154 Extraarticular ankylosis of the knee /156 Extraarticular ankylosis in extension /156 Extraarticular ankylosis in flexion /159 OPEN WOUNDS OF THE KNEE JOINT /160