Proximal subscapularis release for the treatment of adduction–internal rotation shoulder contracture in obstetric brachial plexus palsy

INTRODUCTION The purpose of this paper was to evaluate the results on shoulder function following isolated proximal subscapularis release in children with Erb's palsy. METHODS A retrospective study was conducted on 64 consecutive children with Erb's palsy who underwent a Carlioz proximal subscapularis release between 2001 and 2012. Fifty children with complete records and a minimum follow-up of 2 years were included for evaluation. Age at surgery ranged from 1.3 to 4.5 years (average 2.6 years). Preoperative active shoulder abduction/anterior elevation, active external and internal rotations as well as the Mallet score were compared with those found at 6 and 24 months postoperatively using the Student paired t test, with a confidence interval of 95 %. The results were compared between children <3 years of age at surgery and those older, and between children who had an isolated C5-C6 and those with greater involvement. p < 0.05 was considered statistically significant. RESULTS Active abduction improved 21° at 6 months and 31° (total) at 2 years (p < 0.01) with an overall Mallet abduction score improvement of 0.58 at 6 months and 0.6 (overall) at 2 years (p < 0.01). Active external rotation improved 52° at 6 months and 35° (total) at 2 years (p < 0.01) with an overall Mallet external rotation score improvement of 1.3 at 6 months (p < 0.01) and 0.52 (overall) at 2 years (p = 0.013). There was no statistically significant change in internal rotation (p = 0.37). We found no correlation between the child's age or the severity of involvement at surgery and the end result. CONCLUSION Proximal subscapularis release according to Carlioz is simple and effective in improving overall shoulder function in children with obstetric brachial plexus palsy, mainly abduction and external rotation. Improvement tends to reach a plateau around 6-12 months postoperatively.