Shoulder Reconstruction for Brachial Plexus Birth Injuries: An In-Depth Review and Case-Based Update.

Brachial plexus birth injuries can result in significant shoulder dysfunction with limitations in range of motion, decreased strength, and risk of glenohumeral joint deformity. This comprehensive review examines current approaches for management of the shoulder including surgical reconstruction following these injuries. Serial clinical exams and selective imaging are critical to determine optimal timing of surgery based on recovery potential and joint pathology. Biceps recovery is monitored monthly from birth and, if absent by 5-6 months, serves as an indication for nerve reconstruction with nerve grafting, transfers, or both. Glenohumeral contracture, deformity, and dislocation commonly occur in infancy and are assessed by exam, ultrasound, and MRI scan. Procedural intervention is indicated when there is loss of passive external rotation, active motor weakness, and/or glenohumeral deformity/dislocation is present. Contracture release and joint reduction to center the humeral head on the glenoid is performed early when there are limitations in passive external rotation not resolved with therapy. Glenoid remodeling can occur when reduction is performed early (6 months to 2-3 years). Surgical options include (1) extraarticular contracture releases (e.g., botox, subscapularis slide) and closed reduction, (2) intraarticular arthroscopic/open release and reduction, and (3) contracture release/joint reduction combined with tendon transfers (latissimus-teres major most common). The lower trapezius transfer is increasingly used for active external rotation as it spares internal rotation strength and has an excellent line of pull reproducing that of the infraspinatus. For advanced joint deformity, humeral/ glenoid osteotomies are utilized. A nuanced, individualized approach is required considering the child's deficits, pathoanatomy, and age in a case-based manner. Open communication between providers and families is imperative to optimize care. This review provides a comprehensive analysis of current shoulder reconstruction approaches following brachial plexus birth injuries. •Failure of biceps recovery by 5-6 months for extraforaminal injuries (C5-C6; C5-C6-C7) indicates nerve surgery intervention between 5-9 months using nerve grafting, transfers, or a combination to restore function in the shoulder (and as for indicated elbow, forearm, and wrist).•Glenohumeral joint complications such as contracture, deformity, and dislocation often emerge during early infancy to the first 2-3 years due to incomplete recovery. Physical exams focus on the progressive limitations of external rotation (ER), and advanced imaging (ultrasound or MRI) is needed when passive ER falls below 30 degrees and/or there's posterior humeral head prominence.•In cases of glenohumeral deformity and dislocation, it's crucial to center and stabilize the humeral head on the glenoid during reduction. Early intervention (6 months to 2-3 years) can result in glenoid remodeling.•Surgical options range from extraarticular contracture releases, such as botox and subscapularis slide, to intraarticular arthroscopic or open release and reduction. Depending on patient age and deformity severity, reduction surgeries can be standalone or combined with tendon transfers. It's vital to adopt a patient-tailored, stepwise approach during surgery.•The latissimus dorsi-teres major transfer restores active external rotation, while the lower trapezius offers an alternative for active ER that preserves internal rotation strength. In situations with pronounced deformities in older patients, glenoid and humeral osteotomies can be performed.