[Analysis on the effect of subfascial anterior transposition of the ulnar nerve with vascularized fascial flap combined with intraoperative neurophysiological monitoring in the treatment of moderate to severe cubital tunnel syndrome].

To investigate the effect of vascularized pedicled fascial subcutaneous ulnar nerve transposition surgery combined with intraoperative neurophysiological monitoring (IONM) in the treatment of moderate to severe cubital tunnel syndrome (CuTS). A retrospective analysis was conducted on clinical data of CuTS patients who underwent vascularized pedicled fascial subcutaneous ulnar nerve transposition surgery at Affiliated Hospital of Zunyi Medical University between January 2021 and December 2024. IONM was combined to assess nerve conduction function, comparing changes in compound muscle action potential (CMAP) parameters before and after ulnar nerve decompression. The patients were followed up until February 15, 2025. A total of 42 patients were included, consisting of 31 males and 11 females, with a mean age of (47±8) years and a median disease duration of 18 (2-86) months. There were 28 moderate cases and 14 severe cases. Intraoperative electrophysiological monitoring revealed that 28 patients successfully generated waveforms under compression. The conduction velocity [(36.52±8.66) vs (29.25±10.42) m/s] and amplitude [(4.12±0.44) vs (2.52±0.40) mV] of ulnar nerve after release were higher than those before release, and the latency period [(4.22±0.62) vs (5.45±0.66) ms] was shorter than that before release (all P<0.001). Among the 14 cases with no detectable waveforms preoperatively, 10 cases (71.42%) showed detectable waveforms intraoperatively. The median follow-up time was 22 (3-48) months, during which alleviation of nerve symptoms was observed in the short term (3-6 months), and the excellent rate of elbow tunnel syndrome functional score was 95.3% in the long term (>1 year), with no postoperative recurrence of nerve compression or iatrogenic injury. Vascularized pedicled fascial subcutaneous ulnar nerve transposition surgery combined with intraoperative IONM has a favorable effect for moderate to severe CuTS.