"Redefining the Incidence of Infantile Glenohumeral Dysplasia Following Brachial Plexus Birth Injury".

Abstract

Background: Glenohumeral dysplasia (GHD) is a well-documented sequelae following brachial plexus birth injury (BPBI). Despite its morbidity, the precise incidence of infantile GHD varies widely in the literature.

Methods: This prospective cohort study included consecutive patients diagnosed with a non-transient BPBI between November 2021-November 2023. Patients were enrolled into the study from a specialized, high-volume brachial plexus clinic. A diagnosis of GHD was made by an alpha angle measurement on ultrasonography greater than 30° in the setting of abnormal shoulder function, as indicated by Active Movement Scale (AMS) scores for shoulder abduction, shoulder flexion, and external rotation.

Results: Forty-two infants with a diagnosis of non-transient BPBI were initially seen at a mean age of 1.6 months. During continuous follow-up, 50% (n=21) of patients were diagnosed with GHD with a mean alpha angle of 35° (SD 8) and at a mean age of 3.2 (SD 1.4) months. At the time of diagnosis, infants had a median AMS score of 4 (interquartile [IQR] 3, 5) for shoulder abduction, 5 (IQR 3, 5) for shoulder flexion, and 4 (IQR 2, 5) for external rotation. The presence of upper extremity fracture was significant when comparing BPBI patients with GHD and those without, though the relative risk was not significant.

Conclusions: This study demonstrates a high incidence of GHD in a prospective evaluation of infants with BPBI using serial ultrasonography. Those caring for BPBIs should be aware of such a common sequela and initiate early screening and management protocols to prevent and treat the deformity.