Double Fascicular Nerve Transfer From the Ulnar and Median Nerves to the Musculocutaneous Nerve for Restoration of Elbow Flexion: Surgical Technique and Preliminary Results

Traumatic C5-C6 brachial plexus palsies result in complete loss of elbow flexion, and restoring this function is the top priority in upper plexus reconstruction.Double fascicular nerve transfer at the brachial canal, combining an ulnar nerve fascicle transferred to the biceps branch and a median nerve fascicle transferred to the brachialis branch of the musculocutaneous nerve, is an established technique for this indication.We report a retrospective series of five consecutive patients with post-traumatic C5-C6 palsy who underwent double fascicular nerve transfer at the Department of Traumatology and Orthopedics A, Mohammed VI University Hospital, Marrakech, between January 2019 and December 2022.Of the seven patients with traumatic C5-C6 palsy assessed during this period, one declined surgery, and one was lost to follow-up before surgery; all five operated patients were included, with no postoperative loss to follow-up.All patients were operated on within three to six months of injury, and outcomes were assessed using the Medical Research Council grading scale over a mean follow-up of 20 months (range 17-23).The mean age was 35 years (range 29-43), with a male predominance (4/5), and all patients had been involved in motorcycle road traffic accidents.The mean time to clinical reinnervation (M1) was 4.0 months, and the mean time to M3 strength was 7.6 months (n = 3 patients with a recorded date); the only patient who reached M4 did so at 13.2 months.At the last follow-up, one patient had reached M4, three had reached M3, and one had reached M2: four of five patients (80%) achieved M3 or better, and one of five (20%) achieved M4 or better.Ulnar donorsite deficits, assessed clinically, were observed in two patients and persisted at final follow-up (one with persistent paresthesia and improving key pinch weakness, one with persistently reduced ulnar deviation strength), with no reported median donor-site morbidity or surgical complications.In this small preliminary series, double fascicular nerve transfer using ulnar and median nerve fascicles to the musculocutaneous nerve was feasible in our setting, with a rate of useful antigravity elbow flexion comparable to those reported in published series but a markedly lower rate of recovery to M4 strength and persistent ulnar donor-site deficits in two of five patients.Larger prospective studies are needed to confirm these findings.