Retained hand function following transection of the ulnar nerve.

Generally, complete transection of a peripheral nerve results in cessation of function of the muscles innervated by such a nerve. We report a case of a child with a traumatically transected ulnar nerve who retained complete hand function. The authors believe this retention of hand function was due to a Martin-Grüber anastomosis, which is an interneural communication between the ulnar and median nerve in the forearm. Such neural variations should be considered when evaluating injuries to the nerves of the upper extremity (Fig. 2, Ref. 5).