Glenohumeral dysplasia secondary to brachial plexus birth palsy
Presentation
Left brachial plexus birth palsy.
Patient Data
Severe deformity of the glenoid and humeral head. The glenoid appears convex towards the humeral head with loss of its posterior margin most likely the result the pressure from the humeral head. The humeral head appears dysplastic relatively flattened, displaced posteriorly.
The glenoid version can be measured using the method described by Friedman et al 1. The angle formed by the line drawn between the anterior and posterior aspect of the glenoid margins and the line crossing the previous line at the midpoint of the glenoid. The angle between those two lines is measured in the posteromedial quadrant, followed by subtraction of 90° from its value. A negative value of that angle indicates a glenoid retroversion, while a positive value indicates an anteversion.
In our case, the gleno-scapular angle measured at the posteromedial quadrant was at 60°. The glenoid version is 60°-90° = -30° (a negative value of the angle as in this case indicates a glenoid retroversion).
The entire humeral head appears posterior to the scapular line which it was classified as total luxation of the humeral head.
Case Discussion
Case of severe humeral head and glenoid dysplasia with complete posterior dislocation of the humeral head.
The main bone deformities secondary to brachial plexus birth palsy include progressive glenoid retroversion; flattening or absence of the glenoid cavity; thinning with loss of the posterior glenoid margin; hypoplasia of the humeral head with posterior subluxation or luxation. Others less common bone anomalies include hypoplasia of the scapula; inferior deviation of the acromion and shortening of the clavicle.
Additional contributor: R. Bouguelaa MD