Distal Anterior Interosseous Nerve Transfer to the Deep Motor Branch of the Ulnar Nerve for Reconstruction of High Ulnar Nerve Injuries

TLDR

Proximal ulnar nerve injuries can cause loss of intrinsic hand muscle function, and distal nerve transfers offer a way to coapt nerves near the target muscles. The study retrospectively evaluated outcomes after transferring the anterior interosseous nerve to the deep motor branch of the ulnar nerve in patients with high ulnar nerve injuries. Eight patients (3 women, 5 men) with a mean age of 38 years underwent the transfer, with a mean interval of 3 months from injury to surgery and an average 18‑month postoperative follow‑up. All patients showed reinnervation of intrinsic hand muscles with improved pinch and grip strength, no pronation deficits, and only one required a secondary tendon transfer, indicating good functional recovery.

Abstract

Proximal ulnar nerve injuries can result in loss of intrinsic muscle function of the hand, and distal nerve transfers provide nerve coaptation close to the target muscle. This retrospective chart review evaluated patient outcome following a distal nerve transfer of the anterior interosseous nerve (AIN) to the deep motor branch of the ulnar nerve. There were eight patient charts reviewed, three women, and five men. The mean patient age was 38 years (standard deviation: 22 years). The mean time from injury to surgery was 3 months (standard deviation: 3 months), and mean postoperative follow-up time was 18 months (standard deviation: 11 months). All patients had reinnervation of the ulnar nerve intrinsic hand muscles with improved postoperative lateral pinch and grip strength. One patient had a secondary tendon transfer. No functional deficit in performing tasks in pronation was reported. The distal nerve transfer of the AIN to the deep motor branch of the ulnar nerve provides good reinnervation of the ulnar-nerve-innervated intrinsic muscles of the hand.