Outcomes of median nerve transfers in high ulnar nerve injuries in adults - Scoping review.

INTRODUCTION

High ulnar nerve (UN) injuries have unfavorable functional prognoses due to the limited distance for axonal regeneration. Median nerve (MN) transfer to the UN has emerged as an alternative treatment for this injury.

METHODS

Analysis of studies following the PRISMA-Sc guidelines was conducted. Studies evaluating MN transfer in the forearm or hand for high UN injuries between 2005 and 2025 were identified and then included. These studies included descriptions of intrinsic muscle function, grip strength (pincer or fist), and reported outcome measures. A descriptive literature review was performed.

RESULTS

Ten studies were included; given the scope of the evidence and its heterogeneity, they are presented in summary terms, without a specific comparison. Patients were primarily young adults, and the most frequent injury was laceration. The time for surgery ranged from 20 days to 18 months. Anterior interosseous nerve transfer showed functional improvements in M3 and M4 in 80% of cases, with a grip strength between 30 and 40kg in 40% of patients. Additionally, thumb opponent muscle branch transfer resulted in a grip strength of 57%±16% and a terminal pinch strength of 71%±24% compared to the contralateral limb.

CONCLUSIONS

Nerve transfer significantly improves pinch strength at M3 or higher in 80% of cases. There is insufficient evidence to recommend one procedure as superior to the other based on the results reported in the literature.