What is Shoulder Arthritis?

Although most people think of the shoulder as several joints, there are really two joints in the area of the shoulder. The shoulder complex is a ball and socket joint and is comprised of 4 main muscles, several bones, and several soft tissue structures. The scapula (shoulder blade), clavicle (collar bone), and humerus (upper arm bone) make up the bony components. The upper portion of your shoulder creates a joint between the clavicle and scapula called your AC joint – acromioclavicular. Your glenohumeral joint is created from the ball (head of the humerus) and socket (glenoid fossa). Covering of each bone consists of articular cartilage (white protective covering) that breaks down within this condition. When osteoarthritis the protective lining of the bone decreases it produces the bones to compress and rub.