Fascicular selection for nerve transfers: the role of the nerve stimulator when restoring elbow flexion in brachial plexus injuries.

PURPOSE

Restoration of elbow flexion is an important goal in brachial plexus injuries. Double nerve transfers using fascicles from ulnar and median nerves have consistently produced good results without causing functional compromise to the donor nerve. According to conventional practice, these double nerve transfers are dependent on the careful isolation of ulnar and median nerve fascicles, which are responsible for wrist flexion, using a handheld nerve stimulator. Here we suggest that fascicular selection by nerve stimulation might not be a necessity when executing double nerve transfers for restoration of elbow flexion in brachial plexus injuries.

METHODS

This is a retrospective case control study in 26 patients with C5, C6 brachial plexus injuries that were managed with double nerve transfers between March 2005 and January 2008. Our technique consisted of transferring 2 fascicles, one each from the ulnar and the median nerve, directly onto the biceps and brachialis motor branches. Contrary to the standard practice, the ulnar or median nerve fascicles were selected without using a handheld nerve stimulator. Results were compared to 21 cases (control group) in which a nerve stimulator was used for fascicular selection. The denervation period ranged from 3 to 9 months.

RESULTS

Twenty-four patients of the study group experienced full restoration of elbow flexion, and 2 had an antigravity flexion of 120° and 110°. The EMG revealed the first sign of reinnervation of biceps and brachialis muscle at 9 ± 2 weeks and 11 ± 2 weeks, as compared to 9 ± 2 weeks and 12 ± 4 weeks in the control group. After surgery, the appearance of initial evidence of elbow flexion, the range and mean of elbow flexion strength, and the difference between preoperative and postoperative grip and pinch strengths were comparable in both groups. At 24 to 28 months follow-up, 19 patients of the study group had M4 power and 7 had M3, compared to 18 and 3 cases, respectively, in the control group. The P values for Medical Research Council grade, strength of elbow flexion, and range of elbow flexion between the 2 groups did not reveal any significant statistical difference.

CONCLUSIONS

Double nerve transfer is a reliable technique for restoring elbow flexion in brachial plexus injuries. There is no advantage of using a nerve stimulator in selecting fascicles before performing the nerve transfer.