Entrapment neuropathy contributing to dysfunction after birth brachial plexus injuries

Area of Science:

• Pediatric Orthopedics
• Neurology
• Surgical Innovation

Background:

• Brachial plexus birth palsy (BPBP) often results in persistent deltoid muscle weakness, impacting shoulder abduction and elevation.
• The exact etiology of this weakness, even with good arm and hand function, remains incompletely understood and potentially multifactorial.
• Clinical findings suggest factors beyond primary nerve injury may contribute to deltoid dysfunction.

Observation:

• A retrospective study examined 10 children (9 months to 8 years) with BPBP, limited shoulder external rotation, and impaired arm elevation.
• These children exhibited position-dependent weakness, hinting at secondary nerve impingement.
• Surgical treatment focused on augmenting shoulder function in these specific cases.

Findings:

• All 10 children demonstrated increased shoulder range of motion post-surgery.
• Eight out of ten children showed significant improvement in shoulder abduction and elevation.
• Intraoperative electrophysiologic monitoring and functional testing supported the findings.

Implications:

• Secondary compression of the axillary nerve within the quadrangular space is identified as a common cause of deltoid weakness in BPBP.
• This finding suggests a distinct pathological entity contributing to persistent shoulder dysfunction.
• Early surgical intervention targeting axillary nerve decompression may be crucial for improving outcomes in affected children.