Radial sensory nerve to anterior interosseous nerve transfer for symptomatic neuromas- clinical outcomes and a transfer classification system

Abstract

Background

Radial sensory nerve (RSN) injuries occur during common surgical procedures or injuries to the wrist and often result in the formation of painful neuromas. Management strategies of primary repair or secondary reconstruction are limited by poor patient satisfaction. We present a targeted muscle reinnervation (TMR) technique, its clinical outcomes, and a novel classification system for the treatment of recalcitrant RSN neuromas with transfer of the RSN to the anterior interosseous nerve (AIN).

Methods

Cadaveric specimens were used to devise a classification system for the transfer. RSN to AIN transfer was performed after simulated injury at three levels: proximal, at, and distal to the bifurcation. The transfer was performed in five patients with symptomatic recalcitrant RSN neuromas. Clinical and patient-reported outcomes were prospectively collected for one year.

Results

A cadaveric classification system was devised to guide nerve transfer. Five patients underwent RSN to AIN transfer for symptomatic recalcitrant RSN neuromas. There was one Zone 1 injury, two Zone 2 injuries, and three Zone 3 injuries. The mean visual analog scale (VAS) pain score significantly improved by 6 ± 2 points. The mean Quick Disabilities of Arm, Shoulder, & Hand (DASH) scores significantly improved by 37 ± 11 points (p < 0.05). The wrist flexion/extension arc significantly improved by 30 ± 14°, and the radial/ulnar deviation arc significantly improved by 10 ± 3° (p < 0.05).

Conclusions

Our classification system can guide intraoperative decision-making for RSN to AIN transfer based on the zone of RSN injury. RSN to AIN transfer resulted in significant improvement in QuickDASH and VAS Pain scores that exceeded the established thresholds for substantial clinical benefit.