Anatomical study of vulnerable sensory and expendable motor nerves for targeted muscle reinnervation in the upper extremity.

Purpose: Targeted muscle reinnervation (TMR) is a new technique for treating symptomatic neuroma, in which a sensory nerve after resection of a painful neuroma is coapted to an expendable motor nerve. There has been little information about optimal motor nerves for TMR of the vulnerable sensory nerves in the upper extremity.

Methods: Fourteen upper extremities of fresh-frozen cadavers were dissected to describe the anatomical course of the vulnerable sensory nerves, which included the superficial radial nerve, the dorsal branch of the ulnar nerve, and the medial and lateral antebrachial cutaneous nerves. The bifurcation, diameter, and entry points in muscles of expendable motor nerves suitable for TMR of the sensory nerves were investigated.

Results: The distal anterior interosseus nerve was available as a donor for TMR of the superficial radial nerve and the dorsal branch of the ulnar nerve in the distal third of the forearm. The motor branch to the pronator teres muscle was suitable for TMR of the medial antebrachial cutaneous nerve. It was possible to transfer the lateral antebrachial cutaneous nerve to the motor branch of the brachioradialis or extensor carpi radialis longus muscles.

Conclusions: The results of this anatomical study provide useful information when TMR is applied for neuromas of the sensory nerves in the upper extremity.