Follow-up Study on the Effects of Tendon Transfers and Open Reduction on Moderate Glenohumeral Joint Deformity in Brachial Plexus Birth Injury

Background: Soft-tissue contractures about the shoulder in patients with brachial plexus birth injury are common and can lead to progressive shoulder displacement and glenohumeral dysplasia. Open or arthroscopic reduction with musculotendinous lengthening and tendon transfers have become the standard of care. The clinical function and radiographic joint remodeling beyond the first 2 years after surgery are not well understood. Methods: We performed a follow-up study of 20 patients with preexisting mild to moderate glenohumeral joint deformity who had undergone open glenohumeral joint reduction with latissimus dorsi and teres major tendon transfers and concomitant musculotendinous lengthening of the pectoralis major and/or subscapularis. Prospective collection of Modified Mallet and Active Movement Scale (AMS) scores and radiographic analysis of cross-sectional imaging for glenoid version, humeral head subluxation, and glenohumeral joint deformity classification were analyzed for changes over time. Results: The average duration of radiographic follow-up was 4.2 years (range, 2 to 6 years). The mean glenoid version improved from -31.8 degrees to -15.4 degrees (p < 0.0001). The mean percentage of the humeral head anterior to the middle of the glenoid (PHHA) improved from 9.6% to 30.4% (p < 0.0001). The mean glenohumeral joint deformity score improved from 3.7 to 2.1 (p < 0.0001). Conclusions: All parameters showed the greatest magnitude of improvement between preoperative measurements and 1 year of follow-up. There were no significant changes beyond the 1-year time point in the Mallet scores, AMS scores, or radiographic outcome measures, possibly because of insufficient power, although trends of improvement were noted for some outcomes. No decline in outcome measures was found during the study period.