Abstract
BACKGROUND: Muscle rebalancing improves shoulder internal rotation contracture due to brachial plexus birth injury but is less effective for correcting marked glenohumeral dysplasia. For severe cases, combining glenoid anteversion osteotomy (GAO) with subscapularis lengthening and tendon transfers is an alternative to external rotation osteotomy of the humerus. We asked how the addition of glenoid osteotomy affects shoulder motion. METHODS: We defined 2 groups who underwent very similar procedures with the exception of GAO: GAO group-combined GAO, subscapularis slide, and tendon transfers for severe glenohumeral dysplasia, and non-GAO group-subscapularis slide and tendon transfers without GAO for cases of milder dysplasia. We compared active and passive rotation, Active Movement Scale (AMS) and Mallet scores. RESULTS: We compared 86 children in the GAO group with 74 children in the non-GAO group with median follow-ups of 58 (IQR1-3:22-101) and 46 (IQR1-3: 24-72) months, respectively. Preoperatively, the children in the GAO group were older (median 79 (range 14-210) months vs. 34 (range 6-204) months) and exhibited a relatively severe distribution of glenohumeral dysplasia than those in the non-GAO group, as expected. The extent of active external rotation (ER) in adduction improved postoperatively in the GAO group by 65° (p < 0.05), and in the non- GAO group by 84° (p < 0.05). Despite loss of the mean end range of internal rotation by 31° and 27°, the total arc of rotation increased by 34° and 57° in the GAO and Non-GAO groups, respectively. At final follow-up, active ER at 90° abduction (p = 0.14), passive ER (p = 0.17), total arc of rotation (p = 0.11), AMS ER (p = 0.45), Mallet global ER (p = 0.9), and Mallet composite (p = 0.9) scores were similar between the groups, irrespective of the glenoid osteotomy. CONCLUSION: The 2 approaches compared here resulted in similar functional outcomes despite different initial severities of glenohumeral dysplasia. Addition of GAO for severe cases does not obviate improved motion. LEVEL OF EVIDENCE: Level III. See Instructions for Authors for a complete description of levels of evidence.