Glenoid

The glenoid, also called the glenoid cavity or glenoid fossa, is a cup-shaped articular surface on the lateral aspect of the scapula. It forms the socket part of the glenohumeral joint, where the humeral head articulates to allow shoulder movement. The socket is relatively shallow and is surrounded by the fibrocartilaginous glenoid labrum, which deepens the cavity and enlarges the contact area between the bones.

Anatomically, the glenoid cavity sits at the edge of the scapular surface and is reinforced by the inferior rim and the surrounding joint capsule. The glenoid labrum attaches to the rim and to the joint capsule, helping to stabilize the articulation and to resist translation of the humeral head. Stability is provided not only by these static structures but also by dynamic muscles of the rotator cuff and periscapular region.

Clinical relevance and variation: The glenoid exhibits variations in depth, orientation (version), and tilt, which influence shoulder stability. Bone loss or dysplasia of the glenoid rim can predispose to recurrent shoulder dislocations. The labrum itself is susceptible to injury, with tears such as SLAP lesions and Bankart lesions being common after shoulder trauma. Glenoid fractures can accompany dislocations and may require different management strategies.

Imaging and treatment: Evaluation typically uses X-ray, CT for detailed bone assessment, and MRI for soft tissue evaluation. Management ranges from conservative treatment for uncomplicated cases to surgical repair of the labrum or capsule, or bone augmentation procedures (for example, procedures that restore glenoid bone stock) to address instability.