Dysplasia epiphysealis hemimelica of the ankle joint: a case report.

Dysplasia epiphysealis hemimelica is a rare non-hereditary epiphyseal disease that mimics synovial chondromatosis of the joints. The disease mainly targets long bones of the lower extremities and tarsal bones. We report one such case manifesting in the lateral tibia of a 13-year-old boy. He presented with a 7-month history of pain and a bony mass (3x4 cm) at the right ankle. The mass restricted ankle dorsiflexion over the lateral malleolar area. It was ossific with a lobulated appearance and reached the marrow with the underlying epiphysis and adjacent bones. The mass was excised completely from the epiphysis. The detached syndesmos was sutured anatomically.