Anterior intramuscular transposition of the ulnar nerve.

The surgical management of cubital tunnel syndrome is well documented in the literature. Anterior intramuscular transposition of the ulnar nerve is indicated for chronic cubital tunnel syndrome with symptoms refractory to conservative therapy. Prompt diagnosis is essential to yield excellent results. Extreme care must be exercised in the performance of anterior intramuscular transposition. The surgeon must know the details of medial epicondylar anatomy and pathophysiology, as well as all possible sites of potential nerve compression. The placement of the transposed nerve in an intramuscular bed requires that all fibrous septae are resected from the shallow trough created for the nerve to avoid scar formation. Postoperatively, the arm is immobilized for 3 weeks, after which range-of-motion exercises are begun. By the eighth postoperative week, most patients are able to resume their regular activities, including manual labor. Recurrence or persistence of symptoms postoperatively typically is traced to an inadequate decompression of the nerve. Common sites of persistent ulnar nerve compression include (1) the medial intermuscular septum, (2) the arcade of Struthers, (3) fibrous bands immediately proximal or distal to the cubital tunnel, (4) persistence or kinking at the arcuate ligament of Osborne, (5) Spinner's ligament or other fascial slings, and (6) incomplete anterior transposition. Anterior intramuscular transposition of the ulnar nerve is attractive for its relative ease of dissection, simplicity, reliability, and low morbidity. Transposition of the nerve into a shallow muscular trough deep only to the flexor-pronator fascia is a logical, effective, and consistently reliable method of treating cubital tunnel syndrome refractory to conservative management.