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Updated: Aug 24, 2026
Development of a Neonatal Rat Model for Brachial Plexus Birth Injury
Published on: March 27, 2026
Glenohumeral deformity in children with internal rotation contractures secondary to brachial plexus birth palsy:
Darissa S Kon1, Ani B Darakjian, Michael L Pearl
1Department of Diagnostic Imaging, Kaiser Permanente Los Angeles Medical Center, Los Angeles, CA, USA. darissa@juno.com
Insights
Shoulder joint deformities are common in children with brachial plexus birth palsy. These specific glenoid shapes correlate with the severity of internal rotation contracture, aiding treatment planning.
Area of Science:
- Pediatric Orthopedics
- Pediatric Radiology
- Brachial Plexus Injury
Background:
- Brachial plexus birth palsy (BPBP) often leads to shoulder joint deformities.
- Residual paralysis in BPBP requires surgical intervention and understanding joint morphology is crucial.
Purpose of the Study:
- To evaluate glenohumeral joint morphology in children with BPBP using intraoperative arthrography.
- To correlate identified joint morphologies with the degree of passive external rotation.
Main Methods:
- Intraoperative arthrography and passive external rotation measurements were performed on 64 children under anesthesia.
- Glenohumeral joints were classified into four categories: concentric, flat, biconcave, and pseudoglenoid.
- Statistical analysis (Kruskal-Wallis test) compared external rotation with glenoid morphology.
Main Results:
- A significant association was found between glenoid deformity type and the severity of internal rotation contracture (P <.001).
- Patients with pseudoglenoid morphology had the most restricted external rotation (median -20 degrees).
- Concentric glenohumeral joints showed the least restriction in external rotation (median 0 degrees).
Conclusions:
- Consistent patterns of glenohumeral joint deformity exist in brachial plexus birth palsy.
- These deformities are significantly correlated with the severity of internal rotation contracture, informing surgical management.
Purpose:
To evaluate, with intraoperative arthrography, joint morphology in children undergoing surgical treatment of residual paralysis of the shoulder resulting in brachial plexus birth palsy and to correlate the morphology with the degree of passive external rotation.
Materials And Methods:
In 64 children (age range, 7 months to 13 years 6 months), an orthopedic surgeon performed intraoperative arthrography and measured passive external rotation while the patient received a general anesthetic. The orthopedic surgeon and three radiologists reviewed arthrograms and in consensus classified glenohumeral joints in one of four categories: concentric, with the humeral head well centered on the glenoid fossa; flat, with flattening of the posterior glenoid; biconcave, with the humeral head in articulation with the posterior of two concavities, which were in the same plane; and pseudoglenoid, with the humeral head in articulation with the more posterior of two concavities, with retroversion and in a plane different from that of the anterior concavity. Kruskal-Wallis test was used to compare preoperative external rotation with four appearances of glenoid.
Results:
Twenty-one children had concentric glenohumeral joints; seven children, flat glenohumeral joints; 19 children, biconcave glenoid; and 17 children, pseudoglenoid. Median passive external rotation was -20 degrees for patients with pseudoglenoid, -10 degrees for those with flat or biconcave glenoids, and 0 degrees for those with concentric glenoids. Presence and type of glenoid deformity were significantly associated with severity of internal rotation contracture (P <.001).
Conclusion:
Consistent patterns of glenohumeral joint deformity in brachial plexus birth palsy were identified and correlated with severity of internal rotation contracture.
