Nerve grafts bridging the thenar branch of the median nerve to the ulnar nerve to enhance nerve recovery: a report of three cases.

We report a nerve graft procedure bridging the thenar branch of the median nerve to the ulnar nerve in three patients with ulnar nerve transection and defect at the mid-forearm. Ulnar nerve function was evaluated with electroneurography and quantitative sensory-motor testing before and after surgery, and at a 6-year follow-up. After surgery all patients showed electroneurographic evidence of median nerve innervation of the intrinsic muscles normally innervated by the ulnar nerve. The average strength was Grade 4 in the intrinsic muscles originally supplied by the ulnar nerve at the final follow-up. Our results indicate that the thenar branch of the median nerve may support ulnar nerve regeneration and so help prevent intrinsic muscles from irreversible atrophy, but our report is preliminary. This procedure should be validated by future clinical data, especially those with complete ulnar nerve transection at or above the elbow. LEVEL OF EVIDENCE: IV.