Glenoid

The glenoid (or glenoid cavity) is a part of the scapula (shoulder blade) that forms the socket of the glenohumeral joint, commonly known as the shoulder joint. This shallow, articular surface is crucial for the wide range of motion of the shoulder.

Anatomy

The glenoid cavity is located on the lateral angle of the scapula. It is a shallow, pyriform articular surface, which is directed laterally and forward. The cavity is broader below than above and its vertical diameter is the longest.

The glenoid cavity is covered with articular cartilage, which is thicker at the periphery than at the center. This cartilage helps in the smooth movement of the humerus head within the joint.

Function

The primary function of the glenoid is to serve as the socket for the head of the humerus, forming the glenohumeral joint. This joint is a ball-and-socket type, allowing for a wide range of movements including abduction, adduction, flexion, extension, internal rotation, and external rotation.

Clinical significance

The glenoid cavity can be involved in various shoulder pathologies. One common condition is a glenoid labrum tear, which can lead to shoulder instability and pain. The glenoid labrum is a fibrocartilaginous rim attached around the margin of the glenoid cavity, which deepens the cavity and provides stability to the shoulder joint.

Another condition is glenoid dysplasia, a developmental anomaly that can affect the shape and depth of the glenoid cavity, potentially leading to shoulder instability.

Surgical considerations

In cases of severe shoulder instability or arthritis, surgical interventions such as glenoid resurfacing or total shoulder arthroplasty may be considered. These procedures aim to restore the function and stability of the shoulder joint.

See also

• Glenohumeral joint
• Scapula
• Humerus
• Shoulder joint

External links

• Scapula on WikiMD
• Shoulder on WikiMD