External rotation humeral osteotomy for brachial plexus birth palsy

In patients with brachial plexus birth palsy, persistent muscular imbalance across the developing shoulder results in progressive glenohumeral dysplasia, characterized by increased glenoid retroversion, humeral head flattening, and posterior subluxation of the humeral head. Soft-tissue procedures-such as tendon transfers and musculotendinous lengthenings--will provide limited functional improvements in the setting of advanced glenohumeral deformity. For patients with internal rotation contracture and external rotation weakness associated with severe glenohumeral dysplasia, external rotation osteotomy of the humerus may be used to improve global shoulder function. The purpose of this article is to review the history, indications, and surgical technique of external rotation humeral osteotomy for patients with brachial plexus birth palsy.