Functioning Free Muscle Transfer for Brachial Plexus Injury: A Systematic Review and Pooled Analysis Comparing Functional Outcomes of Intercostal Nerve and Spinal Accessory Nerve Grafts

Background The aim of this study was to compare postoperative elbow flexion outcomes in patients receiving functioning free muscle transplantation (FFMT) innervated by either intercostal nerve (ICN) or spinal accessory nerve (SAN) grafts. Methods A comprehensive systematic review on FFMT for brachial plexus reconstruction was conducted utilizing Medline/PubMed database. Analysis was designed to compare functional outcomes between (1) nerve graft type (ICN vs. SAN) and (2) different free muscle graft types to biceps tendon (gracilis vs. rectus femoris vs. latissimus dorsi). Results A total of 312 FFMTs innervated by ICNs (169) or the SAN (143) are featured in 10 case series. The mean patient age was 28 years. Patients had a mean injury to surgery time of 31.5 months and an average follow-up time of 39.1 months with 18 patients lost to follow-up. Muscles utilized included the gracilis (275), rectus femoris (28), and latissimus dorsi (8). After excluding those lost to follow-up or failures due to vascular compromise, the mean success rates of FFMTs innervated by ICNs and SAN were 64.1 and 65.4%, respectively. Conclusion This analysis did not identify any difference in outcomes between FFMTs via ICN grafts and those innervated by SAN grafts in restoring elbow flexion in traumatic brachial plexus injury patients.