Osteochondritis Dissecans of the Knee William R. Beach, M.D. Michael R. Magoline, M.D. Orthopaedic Research of Virginia

Osteochondritis Dissecans Definition Localized condition affecting the articular surface of a joint with separation of a segment of cartilage and subchondral bone

Osteochondritis Dissecans History Pare (1840) described removal of loose bodies from the knee Paget (1870) described a “quiet necrosis” Konig (1888) coined “osteochondritis dissecans” from latin “dissec”, to separate

Osteochondritis Dissecans Joints involved Knee by far the most common joint involved (75% of all OCD lesions) with the ankle, elbow, wrist and other joints accounting for the remaining 25%

Osteochondritis Dissecans of the Knee Epidemiology Two forms Juvenile (open physes, better prognosis) Adult (closed physes, poorer prognosis) Males affected 2-3 times as often as females Rarely occurs in patients <10 or >50 years of age Typically seen in young athletic males

Osteochondritis Dissecans of the Knee Sites of involvement Most common: Lateral aspect of medial femoral condyle Weightbearing surfaces of medial and lateral femoral condyles also affected Patella > 1% Patella >1%

Osteochondritis Dissecans of the Knee Etiology Trauma/Ischemia Impingement of tibial spine on femur Repetitive stress injury to subchondral bone leading to vascular compromise Abnormal ossification Genetic Rule out multiple epiphyseal dysplasia

Osteochondritis Dissecans of the Knee Associated Conditions Endocrinopathies Ligamentous laxity Genu valgum Carpal tunnel syndrome Patellar malalignment Sinding-Larsen-Johanssen disease Osgood-Schlatter disease Sports participation starting at a young age

Osteochondritis Dissecans of the Knee Classification (Clanton and DeLee) Grade I: Depressed osteochondral fracture Grade II: Partially detached fragment Grade III: Detached fragment, nondisplaced Grade IV: Loose body

Osteochondritis Dissecans of the Knee Clinical Presentation Pain and swelling (variable) Locking, catching, giving way Loose body sensation Symptoms related to activity

Osteochondritis Dissecans of the Knee Physical Examination Crepitus Especially noticeable in medial compartment Effusion Tenderness Early: poorly localized Late: point tenderness Wilson sign

Osteochondritis Dissecans of the Knee Wilson sign Extend knee from 90 degrees of flexion with tibia internally rotated Positive: pain at 30 degrees of flexion relieved by external rotation of tibia Pain is due to impingement of tibial spine against OCD lesion

Osteochondritis Dissecans of the Knee Imaging studies Plain films Well circumscribed area of sclerotic bone with surrounding lucent line Bone Scan MRI

Osteochondritis Dissecans of the Knee Bone Scan Sensitive for osteoblastic activity Determines potential for repair Stages (Cahill & Berg) I: x-ray +, bone scan – II: x-ray +, bone scan + III: bone scan + with increased uptake of entire femoral condyle IV: increased uptake in ipsilateral tibial plateau (suggests increase stress transfer across joint)

Osteochondritis Dissecans of the Knee MRI Visualizes loose bodies, degree of displacement of lesion More sensitive than plain films Better correlation with arthroscopic findings Distinguishes grade II vs. grade III lesions

Osteochondritis Dissecans of the Knee Treatment: Juvenile Form (open growth plates) Goal: To obtain healing of the lesion before physeal closure Nondisplaced lesions generally heal with conservative management Protected weightbearing to an activity level where knee is asymptomatic Cessation of sports activities Casting/bracing usually not necessary

Osteochondritis Dissecans of the Knee Treatment: Juvenile Form (open growth plates) Displaced lesions generally require surgical intervention Occurred in 34% of lesions in one series (Cahill) Excise fragment if in nonweightbearing zone Reduce and fix lesion if large and in weightbearing zone Goal: Restore congruity of joint surface

Osteochondritis Dissecans of the Knee Treatment: Adult Form (Closed growth plates) Lesions rarely heal with nonoperative treatment Progression may lead to secondary degenerative arthritis Surgical Goals Restore congruity of joint surface Enhance blood supply to fragment Rigidly fix unstable fragments Early motion with protected weightbearing

Osteochondritis Dissecans of the Knee Treatment: Adult Form (Closed growth plates) Surgical Options Drilling Arthroscopic or open reduction and fixation (+/- bone graft) Reconstruction with allograft or ACI

Osteochondritis Dissecans of the Knee Surgical Treatment: Adult Form Articular surface intact (nondisplaced lesion) Retrograde drilling under arthroscopic guidance Stimulates vascular response/promotes healing Articular surface disrupted (displaced fragment) Drill/curettage base of lesion Replace fragment in crater Fix fragment as anatomic as possible Add bone graft if necessary to restore articular congruity

Osteochondritis Dissecans of the Knee Surgical Treatment: Adult Form Excision of fragment Reserved for smaller fragments or lesions that cannot be reconstructed Newer techniques of reconstruction Osteochondral allografts Autogenous osteochondral grafts Autologous cartilage implantation (Carticel)

Osteochondritis Dissecans of the Knee Video Case Presentation

Osteochondritis Dissecans of the Knee Summary Juvenile and adult OCD lesions are frequently encountered by orthopaedic surgeons Knee most common site involved Lesion is most commonly encountered in an athletically active young male Pathology is thought to be due to repetitive stress injury to subchondral bone 50% of juvenile OCD cases will respond to conservative management Goals of surgical management are to restore normal joint congruity and promote healing of the lesion