Hypothesis: The purpose of this study is to evaluate the outcomes of intercostal nerve transfer to the musculocutaneous motor branch for restoration of elbow flexion. Methods: Over a 10-year period, 85 patients underwent intercostal nerve transfers to the musculocutaneous nerve at a single institution. The average age at surgerywas 30.5 years (17-65), mean BMI 29, with 11 females, and were 18 smokers. All patients had brachial plexus injuries with 19 having C5-C7 avulsions while most had C5-T1 avulsions (n=66). All (n=85) patients had grade 0 biceps strength preoperatively. Patients underwent intercostal nerve (ICN) transfer involving combinations of ICN 3-7 to the musculocutaneous nerve. Fifty-five (65%) patients underwent a simultaneous free gracilis muscle transfer to augment elbow flexion (n=24) or obtain wrist/finger flexion (n=31). Eleven patients had a preexisting arterial (subclavian or axillary) injury. Results: At an average follow-up of 2.8 years (range, 1.0-9.2), 46 (54%) of patients recovered at grade III or better elbow flexion strength. 69 (81%) of patients demonstrated signs of muscle recovery on EMG at last follow-up. The mean elbow flexion was 88 degrees (range, 0-150). The patients DASH scores improved from 48.5 preoperatively to 36.5 postoperatively (P < 0.001), and VAS scores decreased from 5.9 (out of 10) to 4.8 postoperatively (P = 0.03). The number (2, 3, or 4) intercostal nerves used did not have a significant impact on any of the final outcomes. The use of a free muscle transfer improved postoperative elbow flexion strength, with 33 (total n=55, 60%) having greater than or equal to III muscle strength, compared to 12 (total n=30, 40%) of those without a free muscle transfer (P = 0.04). There also were improvements in elbow range of motion (92 vs 78) and EMG signs of recovery (85% vs 70%), but these did not reach statistical significance. Free muscle transfer did significantly improve DASH scores (33 vs 44, P = 0.03). Patients with vascular injuries (n=11) had significantly worse rates of elbow flexion recovery, including worse muscle strengths (P < 0.01), DASH scores (P < 0.01), and rates of EMG recover (P < 0.03). 45/75 (61%) of patients without vascular injuries obtained grade III elbow flexion or greater. Summary Points: * Intercostal nerve transfer in the setting of a complete or near complete brachial plexus injury leads to reasonable rates of recovery of elbow flexion. * Preexisting vascular injuries portend a poor outcome. * In these patients with very limited options, intercostal nerve transfer represents a reasonable nerve transfer option.
Wagner, E., Hundepool, C. A., Kircher, M., Spinner, R., Bishop, A., & Shin, A. Y. (2015). Intercostal Nerve Transfer to Restore Elbow Flexion. The Journal of Hand Surgery, 40(9), e12. https://doi.org/10.1016/j.jhsa.2015.06.026