Posterior approach for transfer of the spinal accessory nerve to the suprascapular nerve: an anatomic study

ObjectiveTo introduce a new surgical procedure for restoratio n of shoulder abduction in brachial plexus injury, which is transfer of the desc ending branch of spinal accessory nerve to the suprascapular nerve viaa posterio r approach.MethodsAnatomic study was carried out using 10 embal med and 4 fres h adult cadavers. Totally 28 sides of shoulder area were dissected. The courses, adjacent structures, relationships of the spinal accessory nerve and suprascapu lar nerve at the level of the scapular spine were observed. Based on the anatomi c study, spinal accessory nerve transfer to suprascapular nerve via posterior ap proach in an incision above the superior margin of the scapular spine was design ed. This method was applied clinically in 10 cases. The preliminary results were reported. ResultsAnatomical position of the suprascapular ner ve is relatively constant. 100%(28/28) of the nerves dissected were found under the suprascapular transverse ligament in the suprascapular notch. The descending branch of the sp inal accessory nerve runs beneath the trapezius muscle. At the level of the scap ular spine, it is located 10.42±4.24 mm medial to the medial border of the scap ula. The distance from the accessory nerve to the suprascapular nerve at that le vel is 4.94±1.22 cm. After dissection in an incision above the superior margin of the scapular spine, the proximal segment of accessory nerve can be easily tra nsferred and coapted to the suprascapular nerve without any tension. In 10 clini cal cases, accessory nerve transfer to the suprascapular nerve through posterior approach was successfully carried out. Direct end-to-end anastomosis was done w ithout any tension. Postoperatively, muscle strength of the upper portion trapez ius was unaffected. ConclusionIn the posterior approach, the a natomical positi on of the descending branch of the spinal accessory nerve and suprascapular nerv e is relatively constant. These two nerves are easily dissected via this approac h. This is a safe and reliable procedure for neurotization of the suprascapular nerve.