Comparison of spinal accessory nerve transfer and grafting from C5 to reinnervate suprascapular nerve in brachial plexus birth injury.

Abstract

Nerve roots of upper trunk are usually affected in brachial plexus birth injury. Suprascapular nerve originates from upper trunk and innervates infraspinatus muscle, which is the most important external rotator of shoulder. The two common options for reinnervating suprascapular nerve: from C5 with interposition nerve graft, or directly from spinal accessory nerve. The aim of our study was to compare improvement in shoulder external rotation following brachial plexus reconstruction in patients with suprascapular nerve grafted from C5 or with spinal accessory nerve transfer. We retrospectively evaluated improvement of shoulder function in 16 patients following brachial plexus grafting with suprascapular nerve grafted from C5, and in 15 patients with concurrent spinal accessory nerve to suprascapular nerve transfer. In addition, results of secondary suprascapular nerve reinnervations with spinal accessory nerve after failured nerve grafting (n=7) were compared with the procedure performed at the primary surgery. Mean improvement in external rotation was better in the nerve transfer group (mean 94 degrees, SD 61) compared to the nerve graft group mean 44 degrees (SD 54) (p=0.023). Nerve graft group had a bigger risk for secondary operations to improve active external rotation (p=0.002), but not for anterior release surgeries (p=0.419). Furthermore, outcome of spinal accessory nerve transfer does not worsen after primary grafting of suprascapular nerve from C5 (mean 90 degrees, SD 37) (p=0.875). Spinal accessory nerve transfer results in better active shoulder external rotation when compared with grafting of suprascapular nerve from C5 and reduces the risk for secondary surgery.