Scapular deformity in obstetric brachial plexus palsy: a new finding

Area of Science:

• Orthopedic Surgery
• Pediatric Radiology
• Developmental Biology

Background:

• Obstetric brachial plexus palsy (OBPP) often leads to residual muscle imbalances around the shoulder.
• These imbalances can result in significant bony deformities of the scapula and glenohumeral joint.
• Existing classifications may not fully capture the complex bony changes in OBPP.

Purpose of the Study:

• To describe and classify bony abnormalities in the shoulder girdle of children with OBPP.
• To introduce a novel classification system for these deformities: Scapular Hypoplasia, Elevation and Rotation (SHER).
• To evaluate the correlation between specific bony parameters and clinical presentation.

Main Methods:

• Analysis of bilateral CT scans and 3D reconstructions of the shoulder girdle in 30 OBPP patients (10 months–10.6 years).
• Measurement of multiple anatomical parameters of the scapula and glenohumeral joint.
• Correlation of measured parameters with the visible area of the scapula over the clavicle.

Main Results:

• Affected scapulae were hypoplastic (average 14%) with elongated acromions (average 19%).
• Humeral head subluxation (average 14%) and scapular downward rotation were observed.
• These parameters correlated with the scapular area visible over the clavicle, supporting the SHER classification.

Conclusions:

• The SHER classification provides a tool for diagnosing and objectively evaluating bony deformities in OBPP.
• Understanding these bony changes is crucial for managing shoulder dysfunction in OBPP patients.
• This classification aids in assessing deformity severity and guiding treatment strategies.