Glenohumeral Dysplasia Following Neonatal Brachial Plexus Palsy: Presentation and Predictive Features During Infancy.

PURPOSE: To evaluate the presence and degree of glenohumeral dysplasia (GHD) in infants undergoing surgical exploration for neonatal brachial plexus palsy (NBPP) and to identify potential predictive factors of early maladaptive shoulder morphology.

METHODS: We included all consecutive patients with NBPP who underwent surgical exploration of their brachial plexus and who had a preoperative magnetic resonance imaging scan at our institution over a 3-year period. Demographic, therapy, and surgical data were collected. Imaging was reviewed for glenoid morphology, glenoid version, percent humeral head anterior to the scapula, and alpha angle.

RESULTS: Of 116 infants who presented to our institution during this 3-year period, 19 (16%) underwent surgical exploration and were included in the study. Median age at the time of the scan was 16 weeks (interquartile range, 14-46 weeks). Fourteen of 19 (74%) had GHD of Waters class 2 or increased malformation. Babies who had more severe palsies underwent earlier surgery and had less severe GHD at the time of surgery than did those with less severe palsies who had surgery later. Less severe GHD was associated with more severe palsies, as indicated by Narakas classification and number of root avulsions. Active external rotation was almost universally absent whereas other shoulder movements were present to varying degrees. More severe GHD was associated with greater total shoulder active range of motion and greater pectoralis major muscle mass.

CONCLUSIONS: Glenohumeral dysplasia occurs often and early in NBPP and may occur in the absence of restricted range of motion. Predictors include increasing age and factors related to muscular imbalance. As such, GHD likely affects the functional outcome that may be achieved with reinnervation, and early screening may improve outcomes.

TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.