Glenoid fossa

The glenoid fossa of the scapula, also known as the glenoid cavity, is a shallow, pear-shaped (pyriform) articular surface situated on the lateral angle of the scapula. It is oriented laterally and slightly forward, where it articulates with the head of the humerus to form the glenohumeral joint, a key component of shoulder mobility.

The fossa is broader at its inferior aspect than at its superior aspect, with its vertical diameter being the longest dimension. In its fresh state, the surface of the glenoid fossa is covered with cartilage, providing a smooth interface for articulation with the humeral head.

The margins of the fossa are slightly raised and serve as the attachment site for the glenoid labrum, a fibrocartilaginous structure that deepens the cavity and enhances joint stability.

At the superior aspect of the glenoid fossa lies the supraglenoid tubercle, a small elevation that serves as the attachment point for the tendon of the long head of the biceps brachii muscle. Similarly, at the inferior aspect, the infraglenoid tubercle provides an attachment site for the tendon of the long head of the triceps brachii muscle.