Postoperative radial nerve paralysis caused by fracture callus.

This is a case of late-onset (6 weeks) radial nerve paralysis following open reduction and internal fixation of a comminuted distal humerus fracture. A transected radial nerve within the callus was found at reoperation. The mechanism of transection was thought to be repetitive motion of the nerve across an edge of new bone. The nerve was repaired and tendon transfers done subsequently with less than full functional recovery at 16 months. No such case has been previously reported.