Subtalar and intertarsal joint involvement in hemophilia and juvenile chronic arthritis: frequency and diagnostic significance of radiographic abnormalities.

Because radiological distinction between hemophilia and juvenile chronic arthritis can be difficult, the ankle and foot radiographs of patients affected by these two disorders were evaluated to compare the frequency and pattern of joint involvement. No statistical difference was noted between the frequency of posterior subtalar joint involvement in the two disorders, but, in the juvenile chronic arthritis group, more than 90% of the abnormal posterior subtalar joints were associated with intertarsal involvement. This association was never found in patients with hemophilia. Isolated tibiotalar joint involvement without subtalar abnormalities was significantly more frequent in hemophilia than in juvenile chronic arthritis. Although clinical differentiation between the two disorders is easily made, intertarsal joint involvement could be a useful feature in the radiological distinction of hemophilia and juvenile chronic arthritis.