[Hemimelic epiphyseal dysplasia. Apropos of a case].

Dysplasia epiphysealis hemimelica (tarsomegaly, Trevor's disease) is a rare osteochondrodystrophy producing cartilaginous epiphysial hypertrophy of hemimelic type involving mainly the lower limb. Lesions are generally medialy located (medial condyle of the femur, medial malleolus, talus, tarsal scaphoid and first metatarsal bone) and clinical signs are not specific; therefore radiological diagnosis is very important. The disease gives rise to a massive ossification of the hypertrophic cartilaginous areas and fast degenerative changes (arthrosis) of the involved joints. Surgery is often unsuccessful.