Opponensplasty Using Distal Nerve Transfer in High Median Nerve Injuries: a Case Series

Abstract

Abstract Purpose High median nerve injury leads to absence of thumb opposition and irreversible thenar atrophy. Currently, distal nerve transfer is a new option for opponensplasty. The superiority of nerve transfer over traditional tendon transfer is that in nerve transfer, all thenar muscles may be reinnervated and so thumb functions are fully achieved while in tendon transfer, the goal is to reanimate the function of abductor pollicis brevis. This study aims to describe the results of opponensplasty using distal nerve transfer. Methods This article analyses the results of opponensplasty using transfer of abductor digiti minimi branch of the ulnar nerve to recurrent branch of the median nerve. Clinical outcomes were assessed by objective evaluation of abductor pollicis brevis (APB) strength, degree of thumb opposition, and thenar muscle bulk. APB strength and degree of thumb opposition measured by Medical Research Council (MRC) and Kapandji scoring systems, respectively. Results From 2016 to 2019 six patients of mean age of 29.5 years (five males and one female) with high median nerve injury were considered for opponensplasty using nerve transfer. Clinical improvement including regaining APB strength and thumb opposition was achieved in all patients. Moreover, recovery of thenar atrophy was observed in five patients. Conclusions In high median-nerve injury, early reconstructive intervention can prevent the thenar muscle atrophy and leads to prompt reinnervation and complete restoration of thenar function. Abductor digiti minimi branch of the ulnar nerve is a superior donor for this purpose.