glenoidflaten

Glenoidflaten, or glenoid flattening, refers to a morphological change of the glenoid fossa of the scapula in which the normal concave contour of the socket becomes flatter. The glenoid fossa is the shallow articular surface that forms the socket for the humeral head, commonly augmented by the glenoid labrum to deepen the joint.

Anatomy and function: The glenoid fossa is part of the shoulder glemnohumeral joint, a ball-and-socket articulation that relies on a balance of cartilage, labral depth, and surrounding soft tissues to maintain stability while allowing a wide range of motion. Flattening of the glenoid reduces the depth of the socket, potentially altering contact patterns and increasing translation of the humeral head.

Causes and pathophysiology: Glenoid flattening can occur as part of osteoarthritis, post-traumatic chondral injury, chronic instability with repetitive dislocations, labral degeneration, or inflammatory arthritides. Progressive cartilage loss and subchondral bone remodeling erode the concavity, and bone remodeling at the glenoid rim may further diminish socket depth. The resulting changes can contribute to pain, reduced function, and a tendency toward instability or altered shoulder mechanics.

Diagnosis: Imaging typically shows a diminished glenoid concavity on radiographs, with CT or MRI providing better assessment of bone loss, version, and associated soft-tissue pathology such as labral damage. Clinically, patients may report shoulder pain, limited range of motion, and mechanical symptoms, with a history of prior injuries or instability.

Management: Nonoperative approaches include physical therapy to strengthen the rotator cuff and periscapular muscles, activity modification, and pain control. In advanced cases, surgical options may involve glenoid resurfacing or arthroplasty, bone grafting or glenoid reconstruction, and, for instability with bone loss, procedures such as Latarjet or other augmentations tailored to the extent of damage. Prognosis depends on the underlying cause and severity of the flattening.

See also: Glenoid cavity, shoulder osteoarthritis, glenoid labrum.