Deformities of the forearm in patients who have multiple cartilaginous exostosis.

Thirty-five patients who had multiple cartilaginous exostosis and deformities of the wrist and forearm were evaluated to determine the natural history and prognostic factors for the deformities. Radial and ulnar shortening were correlated linearly (r2 = 0.86), showing that both bones of the forearm were symmetrically involved. The angular growth abnormality of the distal aspect of the radius was correlated with radial shortening (r2 = 0.53) and ulnar shortening (r2 = 0.61), but it had no correlation with negative variance of the ulnar (r2 = 0.30). Carpal slip was an independent factor, with no correlation with any of the factors studied. The ulnar tether theory for deformities of the wrist in patients who have multiple cartilaginous exostosis was not substantiated by this study.