Arthroscopic release of shoulder contracture secondary to obstetric brachial plexus palsy: retrospective study of 18 children with an average follow-up of 4.5 years.

INTRODUCTION

Children affected by obstetric brachial plexus palsy have an internal rotation contracture of the shoulder and a deformed glenohumeral joint. In 2003, Pearl proposed doing an arthroscopic release of the shoulder to restore external rotation and allow the glenohumeral joint to remodel. The goal of the current study was to evaluate the active and passive shoulder external rotation range of motion and glenohumeral joint remodelling in children treated with arthroscopic-directed release.

MATERIALS AND METHODS

Between 2004 and 2010, 18 children with passive external rotation under 10° were treated with shoulder arthroscopy to release the anterior capsule and ligaments and perform a subscapularis tenotomy; no tendon transfer was performed. The average age was 4 years, 2 months. Nine children had an injury at C5C6, four had an injury at C5C6C7 and five had a complete injury. The average follow-up was 4.5 years. The clinical evaluation consisted of active and passive external rotation (ER) with elbow at the side, active internal rotation, and the modified Mallet score. One child who required an external rotation osteotomy of the proximal humerus was excluded from the clinical outcomes. An MRI was performed on both shoulders to assess glenoid retroversion, glenoid type, degree of posterior subluxation (measured by the percentage of humeral head anterior to the middle glenoid fossa) and humeral head hypoplasia.

RESULTS

At the latest follow-up, passive ER was 58° on average and active ER was 42°. Eleven children had regained more than 30° of active ER. The average internal rotation had decreased after the release. The MRI assessment showed that the glenohumeral joint had remodelled in 66% of cases; the glenoid type had improved, the glenoid retroversion had diminished and the humeral head was recentred. Humeral head hypoplasia was found in 28% of cases.

DISCUSSION AND CONCLUSION

Arthroscopic release of the shoulder results in more external rotation and allows for glenohumeral joint remodelling. Tendon transfer is not always necessary to restore active external rotation.

LEVEL OF EVIDENCE

Level IV - Retrospective study.