Dysplasia epiphysealis hemimelica of the ankle in children.

© 2005 Canadian Medical Association D epiphysealis hemimelica (DEH), also known as Trevor’s disease, is a rare developmental disorder affecting the epiphyses; in young children, it usually involves the knee and ankle joints. DEH was first reported by Mouchet and Belot in 1926, who named it tarso megalia. In 1950, Trevor used the term tarso-epiphyseal aclasis. Fairbank in 1956 coined the term dysplasia epiphyseal hemimelica, the term that remains the common usage name for this unusual condition. The etiology of DEH is unknown. Some authors have theorized that the defect is in the regulation of cartilage proliferation or that the disorder may be due to a localized disturbance of the pre– postaxial part of the apical cap of the limb bud in early fetal development. It does not appear to be genetically transmitted, and no case of malignant transformation has been reported. The incidence of DEH has been estimated at 1 in 1 000 000. It is more common in males (3:1) and white Caucasians, and usually presents in childhood or early adolescence. The most common sites affected are around the knee, usually on the medial side of the tibial or femoral epiphysis, and the ankle, particularly the talus and the medial aspect of the fibular and tibial physis (Fig. 1). The natural history of DEH is that of continual growth of the lesion until skeletal maturity, at which time further enlargement ceases. The aim of this study was to examine the effects of DEH on ankle function and development and to recommend a treatment regime for this unusual but disabling condition.