GlenoidsLabrum

The glenoid labrum, or glenoid labrum of the shoulder, is a fibrocartilaginous rim attached to the margin of the glenoid fossa of the scapula. It encircles the rim of the glenoid cavity to deepen the socket, contributing to the stability of the glenohumeral joint. The labrum also serves as an attachment for the joint capsule ligaments and, at its superior portion, the long head of the biceps tendon.

Anatomy and attachments: The labrum surrounds the glenoid rim and is traditionally described as consisting of regions such as superior, anterosuperior, anteroinferior, and posteroinferior. It blends with the joint capsule and is firmly anchored to the glenoid margin. The long head of the biceps tendon attaches to the superior aspect of the labrum, often referred to as the biceps-labral complex.

Function: By deepening the glenoid cavity, the labrum enhances passive stability of the shoulder, helps distribute contact forces, and provides a fixed attachment site for the capsule and ligaments. Its integrity is important for maintaining normal shoulder mechanics, particularly in overhead and throwing activities.

Clinical significance: The labrum can be injured through acute dislocations, repetitive overhead use, or degenerative processes. Common conditions include SLAP lesions, which involve the superior labrum extending from anterior to posterior; Bankart lesions, which involve avulsion of the anteroinferior labrum with dislocation. Symptoms typically include shoulder pain, instability, and limited range of motion. Diagnosis is aided by MRI or MR arthrography, with treatment ranging from conservative management to arthroscopic repair or debridement depending on injury type and patient factors.