Ulnar nerve palsy following rotational osteotomy of congenital radioulnar synostosis.

Two successive cases of ulnar nerve palsy following rotational osteotomy through a congenital radioulnar synostosis are described. Entrapment of the ulnar nerve by the fascia connecting the two heads of the flexor carpi ulnaris was documented in one patient. Recommendations to avoid this complication include shortening of the forearm at the osteotomy site and the release of unyielding soft tissue restraints. Rotational osteotomy at the distal radial metaphysis may provide a safe, alternative approach in the surgical management of this difficult problem.