In Situ Neurolysis of Ulnar Nerve for Patients With Failed Anterior Subcutaneous Transposition – A Case Series

BACKGROUND: Various surgical techniques have been attempted to treat patients with failed anterior subcutaneous transposition performed for cubital tunnel syndrome. OBJECTIVE: To analyze intraoperative findings of failed anterior subcutaneous transposition and to report the outcome of in Situ neurolysis of ulnar nerve. METHODS: Patients who, under diagnosis of failed anterior subcutaneous transposition of ulnar nerve, underwent in Situ neurolysis between 2001 and 2018 were included in this study. We excluded patients with follow-up of less than one year, records of traumatic ulnar nerve injury, and concomitant double crush syndrome such as cervical spondylosis causing radicular pain, ulnar tunnel syndrome, or thoracic outlet syndrome. Surgical outcomes were evaluated using visual analog scale (VAS) pain score and Disabilities of the Arm, Shoulder, and Hand (DASH) score, which were assessed before and after surgery. A total of 28 elbows in 27 patients whose average age was 58.5 (range, 31-76) yr were enrolled, and the duration of follow-up was 5.8 (range, 1.0-14.9) yr. RESULTS: The most common pathologic finding identified during operation was severe adhesion of the transposed nerve in all elbows, followed by incomplete decompression of deep flexor-pronator aponeurosis in 26 elbows (93%). The average VAS pain score improved from 4.9 (range, 2-7) to 1.3 (range, 0-5), and the average DASH score from 31.7 (range, 18.1-66.7) to 14.1 (range, 5.0-46.6). Of the 28 elbows, 27 (96.4%) showed improvement of preoperative symptoms. CONCLUSION: In Situ neurolysis of ulnar nerve for patients with failed anterior subcutaneous transposition resulted in satisfactory outcome.