Results of Reinnervation of the Biceps and Brachialis Muscles with a Double Fascicular Transfer for Elbow Flexion

PURPOSE: To report the results of a surgical technique of nerve transfer to reinnervate the brachialis muscle and the biceps muscle to restore elbow flexion after brachial plexus injury.

METHODS: Retrospective review was performed on 6 patients who had direct nerve transfer of a single expendable motor fascicle from both the ulnar and median nerves directly to the biceps and brachialis branches of the musculocutaneous nerve. Assessment included degree of recovery of elbow flexion and ulnar and median nerve function including pinch and grip strengths.

RESULTS: Clinical evidence of reinnervation was noted at a mean of 5.5 months (SD, 1 mo; range, 3.5-7 mo) after surgery and the mean follow-up period was 20.5 months (SD, 11.2 mo, range, 13-43 mo). Mean recovery of elbow flexion was Medical Research Council grade 4+. Postoperative pinch and grip strengths were unchanged or better in all patients. No motor or sensory deficits related to the ulnar or median nerves were noted and all patients maintained good hand function. No patients required additional procedures to further improve elbow flexion strength.

CONCLUSIONS: Transfer of expendable motor fascicles from the ulnar and median nerves successfully can reinnervate the biceps and brachialis muscles for strong elbow flexion. The reinnervation of the brachialis muscle, the primary elbow flexor, as well as the biceps muscle provides an additional biomechanical advantage that accounts for the excellent elbow flexion strength obtained using this technique. Direct coaptation of the nerve fascicles was performed without the need for nerve grafts and there was no functional or sensory donor morbidity.