Osteoarthritis, also called degenerative arthritis, is a gradual breakdown of cartilage in the joints. Cartilage is a tough, flexible connective tissue that protects the ends of bones in the joints. Osteoarthritis of the shoulder can severely impact a person's lifestyle.
Osteoarthritis commonly develops as a result of the wear and tear of aging. It also frequently results from traumatic injury to the joint. Osteoarthritis of the shoulder is more common in older people, in women, and in people who have occupations that place increased stress on the shoulder. People who have certain diseases, bone deformities or a genetic predisposition are also at a higher risk.
In a healthy shoulder, the head of the humerus is covered by a layer of cartilage. Healthy cartilage allows the bone to glide smoothly within the joint. But in a shoulder with osteoarthritis, this cartilage begins to deteriorate and wear away. Repetitive motion or injury may speed this deterioration. Eventually, the bone of the humerus may rub directly against the bone of the shoulder socket.
This rubbing can cause the gradual growth of bony bumps along the edge of the joint. These bumps, called bone spurs (or osteophytes), can cause joint pain.
Symptoms of osteoarthritis of the shoulder may include pain in the shoulder and arm. Movement may increase this pain. The shoulder may feel tender when pressure is applied. The person may experience a grating sensation when moving the arm. The shoulder may feel stiff, and this stiffness may interfere with the arm's range of motion.
Treatment options depend on the severity of the arthritis. In the early stages, the shoulder may be treated with non-steroidal anti-inflammatory medications, corticosteroid injections, and physical therapy. If these methods are not helpful and if the shoulder continues to deteriorate, surgery may be needed to repair or replace the joint.