Subluxation in the Arthritic Shoulder
Frederick A. Matsen, Jason E. Hsu
Abstract
»: The term "subluxation" means partial separation of the joint surfaces. In the arthritic shoulder, "arthritic glenohumeral subluxation" refers to displacement of the humeral head on the surface of the glenoid. »: The degree of arthritic glenohumeral subluxation can be measured using radiography with standardized axillary views or computed tomography (CT). »: Shoulders with a type-B1 or B2 glenoid may show more posterior subluxation on an axillary radiograph that is made with the arm in an elevated position than on a CT scan that is made with the arm at the side. »: The degree of arthritic glenohumeral subluxation is not closely related to glenoid retroversion. »: The position of the humeral head with respect to the plane of the scapula is related to glenoid retroversion and is not a measure of glenohumeral subluxation. »: Studies measuring glenohumeral subluxation before and after arthroplasty should clarify its importance to the clinical outcomes of shoulder reconstruction.