Shoulder: Glenohumeral Instability

The glenohumeral joint is a classic ball and socket type joint which allows a broad range of movement but whose shallow glenoid component compromises the inherent stability of the joint. Only 25–30% of the humeral head contacts the glenoid surface [1]. The joint is fortified by both intrinsic and extrinsic components. Compromise of any of the intrinsic or extrinsic stabilizers of the joint can lead to joint laxity and result in either unidirectional or multidirectional glenohumeral instability.Imaging, specifically MRI and MR arthrography, provides a reliable means of identifying structural features contributing-to or associated with glenohumeral instability, which may be critical factors in determining optimal management of patients with instability of the glenohumeral joint.