Lengthening the ulna in patients with hereditary multiple exostoses.

Deformity of the forearm is common in patients with hereditary multiple exostoses, producing cosmetic and functional impairment in which shortening of the ulna is a significant factor. The results of ulnar lengthening in 10 forearms of eight patients are reported. Lengthening was performed by osteotomy of the shaft followed immediately by a bone graft and internal fixation, or by gradual distraction with an external fixator. In all patients the appearance was improved and the range of radial deviation at the wrist was increased. In most patients forearm movement and radial head stability were improved. Partial recurrence of the deformity was seen during the follow-up of skeletally immature patients, but in general ulnar lengthening was found to be a useful operation.