Restoration of shoulder abduction by transfer of the spinal accessory nerve to suprascapular nerve through dorsal approach: a clinical study.

BACKGROUND: In recent years, transfer of the spinal accessory nerve to suprascapular nerve has become a routine procedure for restoration of shoulder abduction. However, the operation via the traditional supraclavicular anterior approach often leads to partial denervation of the trapezius muscle. The purpose of the study was to introduce transfer of the spinal accessory nerve through dorsal approach, using distal branch of the spinal accessory nerve, to repair the suprascapular nerve for restoration of shoulder abduction, and to observe its therapeutic effect.

METHODS: From January to October 2003, a total of 11 patients with a brachial plexus injury and an intact or nearly intact spinal accessory nerve were treated by transferring the spinal accessory nerve to the suprascapular nerve through dorsal approach. The patients were followed up for 18 to 26 months [mean (23.5 +/- 5.2) months] to evaluate their shoulder abduction and function of the trapezius muscle. The outcomes were compared with those of 26 patients treated with traditional anterior approach. And the data were analyzed by Student's t test using SPSS 10.5.

RESULTS: In the 11 patients, the spinal accessory nerves were transferred to the suprascapular nerve through the dorsal approach successfully. Intact function of the upper trapezius was achieved in all of them. In the patients, the location of the two nerves was relatively stable at the level of superior margin of the scapula, the mean distance between them was (4.2 +/- 1.4) cm, both the nerves could be easily dissected and end-to-end anastomosed without any tension. During the follow-up, the first electrophysiological sign of recovery of the infraspinatus appeared at (6.8 +/- 2.7) months and the first sign of restoration of the shoulder abduction at (7.6 +/- 2.9) months after the operation, which were earlier than that after the traditional operation [(8.7 +/- 2.4) months and (9.9 +/- 2.8) months, respectively; P < 0.05]. The postoperative shoulder abduction was 62.8 degrees +/- 12.6 degrees after transfer of the spinal accessory nerve, better than that after the traditional (51.6 degrees +/- 15.7 degrees). All the 11 patients could extend and externally rotate the shoulder almost normally.

CONCLUSIONS: The accessory nerve transfer through dorsal approach is a safe and reliable procedure for the treatment of brachial plexus injury. Its postoperative effect is confirmed, which is better than that of the traditional operation.