The treatment of hereditary multiple exostosis of the upper extremity.

Thirty of 50 patients with hereditary multiple exostosis developed significant deformities of the arm in one extremity. The degree of deformity is dependent on the location of the osteochondroma. If the osteochondroma is on the radius, deformity will usually be only minimal. If the osteochondroma is at the distal end of the ulna, the epiphysis usually stops growing. We believe that the ulnar collateral ligament then acts as a tether, very similar to that seen in the ulnar clubhand. The radius then has to either bow or dislocate at the elbow, and the wrist displaces ulnarly. We performed operations on 10 patients that consisted of cutting the ulnar collateral ligament, lengthening the ulna, osteotomizing the radius, and removing any osteochondromas. In the young, growing child, staples are placed across the lateral side of the distal radial epiphysis. The cosmetic results of the surgery were very gratifying. Nine patients also had osteochondromas removed from the hands and the forearms.