Transfer of a Motor Fascicle From the Ulnar Nerve to the Branch of the Radial Nerve Destined to the Long Head of the Triceps for Restoration of Elbow Extension in Brachial Plexus Surgery

Abstract

BACKGROUND AND IMPORTANCE: Restoration of elbow extension has not been considered of much importance regarding functional outcomes in brachial plexus surgery; however, the flexion of the elbow joint is only fully effective if the motion can be stabilized, what can be achieved solely if the triceps brachii is coactivated. To present a novel nerve transfer of a healthy motor fascicle from the ulnar nerve to the nerve of the long head of the triceps to restore the elbow extension function in brachial plexus injuries involving the upper and middle trunks. CLINICAL PRESENTATION: Case 1 is a 32-year-old man sustaining a right brachial extended upper plexus injury in a motorcycle accident 5 months before admission. The computed tomography myelogram demonstrated avulsion of the C5 and C6 roots. Case 2 is a 24-year-old man who sustained a C5-C7 injury to the left brachial plexus in a traffic accident 4 months before admission. Computed tomography myelogram demonstrated signs of C6 and C7 root avulsion. The technique included an incision at the medial border of the biceps, in the proximal third of the involved arm, followed by identification of the ulnar nerve, the radial nerve, and the branch to the long head of the triceps. The proximal stump of a motor fascicle from the ulnar nerve was sutured directly to the distal stump of the nerve of the long head of the triceps. Techniques to restore elbow flexion and shoulder abduction were applied in both cases. Triceps strength Medical Research Council M4 grade was obtained in both cases. CONCLUSION: The attempted nerve transfer was effective for restoration of elbow extension in primary brachial plexus surgery; however, it should be selected only for cases in which other reliable donor nerves were used to restore elbow flexion.