Osteochondritis dissecans of the ankle
Osteochondritis dissecans (OCD) of the ankle is the end result of the aseptic separation of an osteochondral fragment of the talar dome with the gradual fragmentation of the articular surface. See the main osteochondritis dissecans article for a general discussion on this condition, which mostly affects the knees.
The definition of OCD says that these lesions occur in an immature growing skeleton, however, the symptoms usually have their onset in the adulthood.\
May be asymptomatic for a long period. A common complaint is an intermittent weight-bearing pain. When there is a loose body within the joint, symptoms may be more severe and include intense pain, swelling, instability during walking, and locking.
See the main osteochondritis dissecans article for a general discussion on this condition pathology.
Radiographs are more sensitive if dedicated projections are obtained, such as dorsiflexion and plantarflexion AP of the ankle or with 15° of internal rotation. OCD is predominantly located in the superomedial corner of the talus:
- subchondral halo outlining the osteochondral fragment
- focal concavity of the articular surface
- intra-articular bone fragment may be seen