Background: Closed reduction and chemo-denervation of the internal rotators is commonly used to treat glenohumeral dysplasia in infants with brachial plexus birth injury; however, outcomes are variable, and predictors of failure remain poorly defined. The primary research questions were: (1) what is the failure rate following closed reduction and chemo-denervation, and what factors predict failure? and (2) do radiographic measures of glenohumeral dysplasia correlate with functional shoulder outcomes? Methods: A retrospective cohort study was performed of infants with unilateral brachial plexus birth injury who underwent closed reduction, chemo-denervation of the internal rotators, and shoulder spica casting at a single institution between 2012 and 2024. Patients required a minimum of 1 year of follow-up with preoperative and postoperative ultrasound or magnetic resonance imaging. Failure was defined as a recommendation for additional shoulder surgery within 1 year. Active Movement Scale shoulder scores and radiographic parameters, including alpha angle, percentage of humeral head displacement, and glenoid version, were analyzed. Group comparisons and correlation analyses were performed using nonparametric statistics. Results: Thirty-seven patients met the inclusion criteria. The failure rate was 35.1% (13/37). Instrumentation during delivery was associated with higher failure rates ( P =0.014). Lower birth weight was associated with failure ( P =0.001), whereas preoperative weight was not. Increased shoulder abduction at initial presentation was also associated with failure ( P =0.0003). Among patients without failure, significant improvements were observed in Active Movement Scale scores for shoulder abduction, flexion, and external rotation (all P ≤0.004). Radiographic parameters demonstrated significant remodeling, including improvements in alpha angle and humeral head alignment ( P ≤0.001). The correlation between radiographic measures and functional outcomes was weak overall. Conclusions: Closed reduction and chemo-denervation result in meaningful functional improvement and radiographic remodeling in many infants with brachial plexus birth injury; however, approximately one-third require additional intervention within 1 year. Lower birth weight, delivery instrumentation, and greater initial shoulder abduction were associated with failure. Radiographic improvement correlated poorly with functional recovery, emphasizing the need for combined clinical and imaging assessment. Level of Evidence: Level IV, case series.
Choy et al. (Mon,) studied this question.