Osteochondritis Dissecans of the Knee

William R. Beach, M.D.

Michael R. Magoline, M.D.

Orthopaedic Research of Virginia

Osteochondritis DissecansDefinition

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

Osteochondritis DissecansHistory

• 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 DissecansJoints 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 KneeEpidemiology

• 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 KneeSites 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 KneeEtiology

• 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 KneeAssociated 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 KneeClassification (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 KneeClinical Presentation

• Pain and swelling (variable)

• Locking, catching, giving way

• Loose body sensation

• Symptoms related to activity

Osteochondritis Dissecans of the KneePhysical Examination

• Crepitus– Especially noticeable

in medial compartment

• Effusion• Tenderness

– Early: poorly localized

– Late: point tenderness

• Wilson sign

Osteochondritis Dissecans of the KneeWilson 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 KneeImaging studies

• Plain films– Well circumscribed

area of sclerotic bone with surrounding lucent line

• Bone Scan• MRI

Osteochondritis Dissecans of the KneeBone 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 KneeMRI

• 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 KneeTreatment: 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