Anterior Subacromial Bursa Extension

bursa subacromialis — extensio anterior

The subacromial-subdeltoid bursa extends anteriorly to the coracoid process and the coracohumeral ligament at the rotator interval, forming the subcoracoid component of the subacromial bursal complex. This anterior extension lies between the subscapularis and the anterior coracoacromial arch, and becomes impinged in subcoracoid impingement syndrome where the coracohumeral distance is reduced to less than 6 mm.

Region: Shoulder

Clinical Relevance

Clinical Notes

The anterior subacromial bursa extension is specifically inflamed in subcoracoid impingement — the subscapularis is trapped between the coracoid and the lesser tuberosity during forward flexion and internal rotation. MRI demonstrates anterior subacromial bursal fluid extending medially toward the coracoid with associated subscapularis signal abnormality. Coracoid decompression (removing 5-8 mm of the lateral coracoid tip) at arthroscopy increases the coracohumeral distance and decompresses the anterior bursa from impingement. The anterior bursa is also specifically affected in rotator interval pathology and in adhesive capsulitis where the interval becomes fibrotic.

Pathology

Common Injuries & Conditions

Subcoracoid Impingement Inflaming the Anterior Subacromial Bursa

Reduced coracohumeral distance (less than 6 mm) from prominent coracoid process impinges the subscapularis and anterior subacromial bursa between the coracoid and the lesser tuberosity during shoulder forward flexion and internal rotation; MRI demonstrates anterior subacromial bursal thickening and subscapularis anterior tendinopathy; arthroscopic coracoplasty enlarges the space.