Early Electrophysiological Study of CC7 Transfer to Median Nerve and Deep Branch of Ulnar Nerve by Medial Antebrachial Cutaneous Nerve.

Background: Due to the possibility of intrinsic muscle recovery, we modified the traditional contralateral cervical seventh (CC7) nerve transfer to repair both the median nerve and deep branch of the ulnar nerve (DBUN) for patients with total brachial plexus avulsion (TBPA).

Methods: A retrospective comparative study of different CC7 transfers for patients with TBPA was carried out. The modified group (20 patients) had CC7 transfer to the median nerve and DBUN by ulnar nerve with vascular pedicle and medial antebrachial cutaneous nerve. The control group (20 patients) had traditional CC7 transfer to median nerve by ulnar nerve with vascular pedicle.

Results: Motor unit potentials (MUPs) could be recorded in the abductor digiti minimi (ADM) and dorsal interosseous muscle in 5 and 2 patients, respectively, in the modified group, whereas nobody had MUP in the ADM or dorsal interosseous muscle in the control group. There was significant difference between the 2 groups in the recovery of MUPs in ADM. As for median nerve recovery, there were no statistical differences in the positive rates of MUPs in abductor pollicis brevis. No significant differences of compound motor action potential existed in flexor digitorum profundus of index finger or flexor carpi radialis between the 2 groups.

Conclusions: From the perspective of electrophysiology, it was possible to regenerate intrinsic muscles using CC7 transfer to the median nerve and DBUN by pedicled ulnar nerve and medial antebrachial cutaneous nerve in patients with TBPA while not affecting the recovery of the median nerve.