Evaluation of patients with recurrent symptoms after ulnar nerve transposition.

Focal entrapment of the ulnar nerve occurs most frequently in the region of the elbow, at the ulnar groove or beneath the humeroulnar aponeurosis. Surgical treatment commonly involves transposition of the nerve anterior to the medial epicondyle, in the antecubital fossa. Symptoms may recur after surgery, and, to assess their etiology, we studied 10 patients with recurrent ulnar symptoms after transposition. Conventional motor and sensory conduction studies were performed, as was mapping of nerve position using submaximal stimuli. In 9 of 10 patients, the ulnar nerve at the elbow was located adjacent to the medial epicondyle, rather than in the antecubital fossa. Focal slowing in the region of the elbow was noted in 8 patients, and an additional site of focal slowing was found in the forearm in 3 patients. We conclude that in patients with recurrent symptoms after ulnar nerve transposition postoperative position of the ulnar nerve may be medial, often near the medial epicondyle. This location may predispose the nerve to recurrent trauma or cause traction on the nerve at more distal locations within the forearm. The prevalence of this medial location of the ulnar nerve in asymptomatic postsurgical patients is unknown.