Congenital deficiency of the ulna.

Twenty-three patients with ulnar ray deficiency were studied and the deformities described by combining Kummel's and Swanson's classifications. An individualized, functionally oriented management program is recommended with early resection of the fibrocartilaginous remnant to prevent shortening, radial bowing, and possible malrotation. Rotational deformity can be corrected by wedge osteotomy, rotation osteotomy, or proximal radial ulnar synostosis. Improved motion at the elbow can be obtained by release of contractures or resection of the radial head. Wrist deformity may require resection of the ulnar remnant and a wedge osteotomy of the radius.