Related Experiment Video
Updated: Oct 5, 2025

Reverse Total Shoulder Arthroplasty
Published on: July 5, 2011
Subluxation in the Arthritic Shoulder
Frederick A Matsen1, Jason E Hsu
1Department of Orthopaedics and Sports Medicine, University of Washington, Seattle, Washington.
»:
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.
Related Concept Videos
Muscles of the Shoulder
Anterior Thoracic Muscles
The anterior thoracic muscles include the serratus anterior, subclavius, and...
Muscles that Move the Arm
The pectoralis major has two origins. Its clavicular head originates on the medial half of the clavicle. In contrast, the sternocostal head originates on the costal cartilages of ribs 1-6, the sternum, and the aponeurosis of the external oblique of the...
Bones of the Upper Limb: Humerus
Functional Classification of Joints
The functional classification of joints is determined by the amount of mobility between the adjacent bones. Joints are functionally classified as a synarthrosis or immobile joint, an amphiarthrosis or slightly moveable joint, or as a diarthrosis, a freely moveable joint. Fibrous and cartilaginous joints can be functionally classified as either synarthroses or amphiarthroses, whereas all synovial joints are classified as diarthroses.
Synarthrosis
An...
Knee Joint
A total of seven ligaments support the knee joint. The patellar ligament, which is also attached to the quadriceps femoris...
Structural Joints: Synovial Joints

