Transfer of fascicles from the ulnar nerve to the nerve to the biceps in the treatment of upper brachial plexus palsy

Background: The transfer of one or more ulnar nerve fascicles to the nerve to the biceps can restore elbow flexion in patients with upper brachial plexus palsy. The purposes of the present retrospective study were to evaluate the results of this procedure, to measure the delay in reinnervation of the biceps muscle, and to define the indications for a secondary Steindler flexorplasty. Methods: Thirty-two patients with an upper nerve-root brachial plexus injury were reviewed at an average of thirty-one months after the nerve fascicle transfer. The average age of the patients was twenty-eight years. The average time between the injury and the operation was nine months. Patients were evaluated with regard to reinnervation of the biceps, ulnar nerve function, elbow flexion strength, and grip strength. Results: The average time required for reinnervation of the biceps after nerve fascicle transfer was five months. No motor or sensory deficits related to the ulnar nerve were noted clinically. The average grip strength at the time of the last follow-up was 25 kg (an improvement of 9 kg compared with the preoperative value). After the nerve transfer, twenty-four patients achieved grade-3 elbow flexion strength or better according to the grading system of the Medical Research Council. A Steindler flexorplasty was performed as a secondary procedure in ten patients with persistent grade-3 flexor strength or worse. In eight of these cases, elbow flexion strength improved after nerve transfer and flexorplasty. Overall, thirty of the thirty-two patients achieved a good result (grade-4 strength) or a fair result (grade-3 strength). Conclusions: We recommend this procedure for brachial plexus injuries involving the C5-C6 or C5-C6-C7 nerve roots. This procedure spares the C5 nerve root and other nerves for grafting or transfer elsewhere. A secondary Steindler flexorplasty is indicated for patients who have persistent grade-3 elbow flexion strength or worse for at least twelve months after nerve fascicle transfer. Level of Evidence: Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.