Ulnar nerve compression following flexor digitorum superficialis tendon transfers around the ulnar border of the forearm to restore digital extension: case report.

This case report describes a complication that occurred following long and ring finger flexor digitorum superficialis tendon transfers routed around the ulnar border of the forearm to restore digital extension. An ulnar mononeuropathy developed in the early postoperative period that was characterized by decreased ring and small finger sensation and interosseous muscle weakness. Operative exploration demonstrated extrinsic compression of the ulnar nerve by the long and ring finger flexor digitorum superficialis tendons. When superficialis tendon transfers are chosen to restore digital extension, passage around the radial side of the forearm or through the interosseous space are recommended to avoid this potential complication.