Remodeling after arthroscopic reduction of glenohumeral joint in adduction internal rotation shoulder deformity in obstetric brachial plexus palsy

Abstract

Background: Lesions of the upper trunk in obstetric brachial plexus palsy (OBPP) commonly leads to long-term shoulder dysfunction. The constant internal rotation lead to early glenohumeral (GH) joint deformity by 6 mo of age and to advanced deformity by 2 yr. Halting or reversing GH deformity and the percentage of the humeral head anterior to the midscapular line is an important surgical goal to restore shoulder function. The purpose of this study was to assess the ability of arthroscopic anterior release (with or without tendon transfers) to correct GH deformity. Methods: Twenty-one patients were included in this study. The average age was 26 mo (17 to 50 mo). Sixteen patients (76.2%) had C5 or 6 lesion, while five (23.8%) had C5, 6 or 7 lesion. Seven patients had grade II GH deformity (33.3%), ten had grade III (47.6%), and four had grade IV (19.1%). Ten children underwent isolated release and 11 underwent concomitant tendon transfers. Functional and radiographic assessments were used to assess outcome after at least 1-year follow-up. The average follow-up period was 19±7 mo (range 12-41 mo). Results: Significant improvement was noted in both the glenohumeral retroversion angle (GRV) angle and percentage of humeral head anterior to the midscapular line at 1-year follow-up The mean preoperative GRV angle was −27.8 degrees and postoperatively −11.8 degrees. The mean percentage of humeral head anterior to the midscapular line was 25% preoperatively and 43% postoperatively. Aggregate Mallet score also demonstrated statistically significant improvement. Conclusions: Arthroscopic release and reduction of GH joint with or without tendon transfer for the sequela of OBPP was associated with GH remodeling. The current study confirmed that the improvement was achieved after nearly 1-year follow-up. The clinical improvements paralleled the radiographic ones. Level of evidence: IV.