Outcomes of Spinal Accessory to Suprascapular Nerve Transfers for Brachial Plexus Birth Injury

PURPOSE: The results of a spinal accessory nerve to suprascapular nerve transfer (SAN-SSN) for Brachial Plexus Birth Injuries (BPBI) were thus far presented in limited case series. Our study evaluates the recovery of shoulder function of patients who undergone an SAN-SSN for BPBI as a solitary procedure or as part of a multi-nervous reconstruction (MNR) surgery.

METHODS: We retrospectively reviewed the medical records of patients at a single institute who had undergone a SAN-SSN after BPBI. Inclusion criteria were patients with BPBI who undergone SAN-SSN and who had both preoperative and minimum 12 months postoperative Active Movement Scale (AMS) scores. Patients for whom the primary surgery involved tendon transfers were excluded. The primary outcome measures were the AMS scores for shoulder abduction, forward flexion and external rotation and secondary outcomes included the need for further shoulder surgery to improve function.

RESULTS: Of 133 patients who underwent the procedure, 69 met inclusion criteria. 43 (62.3%) patients obtained functional shoulder motion (AMS≥6) following surgery, with 13 (18.8%) patient achieving full recovery of shoulder function against gravity (AMS≥7). 56 (81.2%) patients did not proceed to further tendon transfers or corrective osteotomies to augment shoulder function. MNR procedures were performed in 44 (63.77%) patients, of whom 47.7% have gained functional recovery. In 25 patients for whom SAN-SSN nerve transfer was conducted in isolation 88% have gained functional shoulder motions. Isolated SAN-SSN were conducted at a later age than MNR procedures (12.22 vs 7 months, p=0.001) and had higher preoperative AMS scores (p<0.0001). The anterior and posterior approaches were both found effective when used for SAN-SSN in BPBI.

CONCLUSIONS: SAN-SSN was able to recover functional shoulder motion in BPBI and prevent tendon transfers and corrective osteotomies. Outcomes continue to improve throughout the first three postoperative years, and this time-point should be used as a benchmark for analyzing the results of this procedure.