Osteochondritis Dissecans of the Talus
synonyms: Talus OCD, Osteochondral lesion, transchondral fracture, osteochondral fracture, osteochondral defect
Talar OCD ICD-9
- 732.7 (Osteochondritis dissecans)
Talar OCD Etiology / Epidemiology / Natural History
- Osteochondritis dissecans is a localized injury or condition affecting an articular surface that involves separation of a segment of cartilage and subchondral bone. Schenck RC Jr, JBJS 1996;78A:439
- Posteromedial lesions: often asymptomatic, with no history of trauma. Less risk of osteoarthritis.
- Anteriolateral lesions: usually symptomatic, associated with trauma.
- Anterolateral talar lesions maybe caused by impaction of the talus on the fibula in inversion with the ankle positioned in dorsiflexion. Posteromedial lesions may be caused by inversion with the ankle plantar flexed. (Berndt, JBJS 1959;41:988)
- 98% of lateral lesions and 70% of medial lesions are associated with trauma (Flick Foot Ankle 1985;5:165)
Talar OCD Anatomy
- Lesions are located either posteromedial or anterolateral on the talus.
- The majority of the talus is covered by articular cartilage, limiting its vascular supply and reparative capacity. (Mulfinger GL, JBJS 1970; 52Br:160)
- see also Ankle Anatomy.
Talar OCD Clinical Evaluation
- ankle pain usually localized to side of the talar lesion
- intermittent swelling
- may c/o catching or grinding, instability, frequent giving way
- History of ankle sprain is common.
- May have crepitus with ROM.
- Joint effusion common.
- Tender along tibiotalar joint line either anterolaterally or posteromedially depending on lesion location.
- Talar OCD Note
Talar OCD Xray / Diagnositc Tests
- A/P, Lateral and Mortise views of the ankle. Lesions appear as a well circumscribed area of sclerotic subchondral bone separated fromt he remainder of the epiphysis by a radiolucent line. Often not seen on x-ray
- MRI should be performed on pts suspected on having talar OCD. MRI allows determination of location of lesion as well as integritiy of articular cartilage.
- CT provides best definition of bone fragments seen on plain xray, but not as helpful at detecting suttle lesions.
- Bone scan can identify lesions, but is not helpful in determining integrity of articular cartilage.
- if not traumatic history consider x-ray of contralateral ankle. Contralateral lesions found 10-25% of the time
- stress radiographs indicated if instability detected on exam.
Talar OCD Classification / Treatment
- Berndt, JBJS 1959;41:988
- Stage I=small area of compression of subchondral bone. Treatment = an initial period of no weight bearing with cast immobilization, followed by progressive weight bearing and mobilization to full ambulation by 12 to 16 weeks.
- Stage II=partially detached osteochondral fragment (a flap). Treatment = an initial period of no weight bearing with cast immobilization, followed by progressive weight bearing and mobilization to full ambulation by 12 to 16 weeks.
- Stage III=the most commona completely detached fragment that remains in the underlying crater bed. Posteromedial lesions treated with immobilization and non-weight-bearing for 3-6 months. Lateral lesions treated with arthroscopy. (Pritsch, M, JBJS 1986;68-A: 862)
- Stage IV=completely detached fragment with complete displacement from the crater (a loose body). Treatment = arthroscopy. (Pritsch, M, JBJS 1986;68-A: 862)
- TALAR OCD SURGICAL TECHNIQUE
- Large-Volume Cystic Talar OCD: consider fresh osteochondral allograft (Raikin SM, JBJS 2009;91:2818).
Talar OCD Associated Injuries / Differential Diagnosis
Talar OCD Complications
- Ankle arthritis
- Chronic pain
Talar OCD Follow-up Care
Talar OCD Review References
- Cam-walker x 6 weeks
- Start AROM, PROM at 1wk post-op.
- NWB for 4-8wks or until healing evident on xray.
- Talus Rehab Protocol.
- Ankle/Foot Outcome measures.
- Arthroscopic debridement / drilling: 65-90% Good to excellent results (intermediate f/u)