Anterior transposition of the ulnar nerve

Twenty-four patients with 26 ulnar neuropathies in the elbow region were treated by anterior transposition of the ulnar nerve. The dominant arm was involved in 14 of these patients. Improvement of paresthesia was found in 17 out of 21 (75 per cent) in this series of patients; 10 out of 18 (55 per cent) had improvement of sensation; 7 out of 14 (50 per cent) had less pain; 10 out of 14 (71 per cent) showed an increase in motor power, but only 2 out of 12 patients (16 per cent) with long-standing muscle atrophy showed any improvement in their condition. Electromyographic studies (EMG) were carried out before and after operation. The postoperative studies revealed increased motor conduction velocity within the elbow segment of the ulnar nerve in 15 patients. Slowing in ulnar nerve conduction velocity was found in 3 patients, and in 8 the EMG remained unchanged. Our EMG series indicated that patients with a conduction velocity of less than 40 m/s will certainly benefit more from anterior transposition of the ulnar nerve than will patients whose measurements are within the normal range.