Fibrodysplasia ossificans progressiva.

Three hundred fifty-three previously reported cases of fibrodysplasia ossificans progressiva were reviewed and six new cases were analyzed radiologically. Characteristic findings of fibrodysplasia ossificans progressiva were confirmed and radiographic signs of the disease were demonstrated, including medial cortical thickening of the proximal tibia, narrow lumbar spinal canal, accessory epiphysis of the second phalanx of the fifth finger, and decreased humeral/epicondylar angle.