Incidence of brachydactyly and hand exostosis in hereditary multiple exostosis.

Forty-two radiographs and charts of twenty-two patients with a diagnosis of hereditary multiple exostosis and hand involvement were examined to determine the incidence of hand exostoses and association with brachydactyly. An average of 11.6 exostoses were found per hand. The proximal phalanges and metacarpals are affected in the majority of patients and the thumb and distal phalanges are rarely involved. Most exostoses were located in the juxtaepiphyseal region (61.8%) and typically involved less than 50% of the bone diameter. Brachydactyly can be seen in patients with hereditary multiple exostosis when no exostoses is present; however, the presence of an exostosis results in even more shortening. The location and size of the exostosis had no relationship to increased bone shortening. Operative treatment was required in four of twenty-two patients for debulking and impingement.