Outcomes of shoulder function in spinal accessory nerve-to-suprascapular nerve transfer in adult patients with complete palsy due to brachial plexus injury: a comparison between the anterior and posterior approaches.

Abstract

The spinal accessory nerve (SAN) is frequently used as a donor for reinnervation of the suprascapular nerve (SSN) in the reconstruction of brachial plexus injuries (BPIs). This procedure can be performed using either the anterior or posterior approach. However, no studies have compared the postoperative outcomes between these two approaches in adult patients with complete BPI. Thus, this study aimed to compare postoperative shoulder functional outcomes following the anterior and posterior approaches. Between 2017 and 2022, 48 adult patients with complete palsy following a closed BPI underwent surgery. Inclusion criteria were surgery performed at least 9 months after injury, patient age between 16 and 60 years, and a minimum follow-up period of 2 years. A total of 38 patients met these criteria. The anterior approach was performed in 18 patients, and the posterior approach was used in 20. Shoulder function was assessed at the 2-year follow-up, including shoulder abduction strength and range of motion (ROM), and external rotation (ER) strength and ROM. The posterior approach group demonstrated significantly greater shoulder abduction strength and ER strength compared with the anterior approach group. The median shoulder abduction ROM in the posterior approach group was 53° (IQR 38°-75°), which was significantly greater than that of the anterior approach group (median 35°, IQR 10°-45°). The median shoulder ER ROM of the posterior approach group was 15° (IQR 0°-35°), which was also significantly greater than that of the anterior approach group (median 0°, IQR 0°-10°). The posterior approach in SAN-to-SSN transfer resulted in superior shoulder function outcomes compared with the anterior approach. These findings suggest that the posterior approach might be preferable for optimizing shoulder function recovery in adult patients with complete BPI.