Glenoid labrum

a rim of fibrocartilaginous tissue attached to the edge of the glenoid cavity, which functions to add depth and greater stability to the glenohumeral joint. Also see glenoid labrum.

2. Pathology

Assessment of this structure is important in patients with shoulder instability. Arthroscopy provides accurate results but is invasive; consequently, conventional and computed arthrotomography are preferred. Using the latter methods, the Bankart lesion, Hill Sachs lesion, intra-articular osteocartilaginous bodies, and subluxation or dislocation of the bicipital tendon can be identified. MR imaging, however, is the current imaging method of choice in assessing the glenoid labrum in patients with instability (Fig.1). MR arthrography may also be employed.

Other lesions involving the labrum are tears, ALPSA lesion (anterior labroligamentous periosteal sleeve avulsion), glenoid labrum ovoid mass GLOM , HAGL lesion (humeral avulsion of the glenohumeral ligament), BHAGL lesion (HAGL with humeral avulsion fracture), and SLAP lesion (superior labral anterior and posterior lesion).

In recurrent shoulder dislocations, disruption of the integrity of the glenoid labrum is the most frequent abnormality. In addition, with age the superior portion may become partially detached from the glenoid process. In some cases, however, air or contrast material may track between structures in this region and may be mistaken for partial detachment of the labrum.

The glenoid labrum may undergo degeneration and calcification in osteoarthritis or calcium pyrophosphate dihydrate crystal deposition disease.

DR/RB