Shoulder Arthritis

Osteoarthritis destroys the smooth covering (articular cartilage) at the ends of the shoulder bones. As the cartilage is destroyed, the space between the bones narrows, and eventually, the bones rub together, causing pain, stiffness, and reduced mobility in the shoulder.

Shoulder osteoarthritis affects the glenohumeral joint, a ball-and-socket joint formed between the head of the humerus (upper arm bone) and the glenoid (socket on the shoulder blade or scapula). This joint allows for a wide range of arm motion but is also susceptible to wear and tear, leading to osteoarthritis in some individuals.

Evidence suggests the most common risk factors for developing shoulder osteoarthritis include previous shoulder injury or overuse. Risks include:

• Osteoarthritis typically affects older adults (over age 50), though it can also occur in younger people as a consequence of injury (post-traumatic osteoarthritis).
• Glenohumeral arthritis is more common in women.
• Post-menopausal women are at increased risk.
• Repeated overuse of the shoulder joint, often seen in certain occupations or sports, can lead to osteoarthritis by accelerating the wear and tear of cartilage.
• A previous shoulder joint injury, including fractures and dislocations, can result in post-traumatic arthritis.
• A large rotator cuff tear alters bone alignment and can cause arthritis in the joint.
• Genetics: if a family member has osteoarthritis, you may be more prone to developing osteoarthritis.
• Obesity is associated with systemic inflammation, which can contribute to shoulder arthritis.
• In contrast to osteoarthritis, there are other types of shoulder arthritis, including rheumatoid arthritis, autoimmune arthritis, and gout.

Common symptoms of shoulder arthritis include:

• Persistent pain in the shoulder joint
• Swelling and inflammation
• Stiffness, or reduced range of motion
• A feeling of grinding or catching in the joint during movement

Your UCSF Women’s Sports Medicine Clinic physician will review your medical history, including a history of shoulder injuries, surgeries, and other medical conditions that could impact the shoulder. They will assess your symptoms and their duration, the progression of symptoms, your occupation, the sports you enjoy, and whether there is a family history of osteoarthritis. They will also perform a physical examination to evaluate your pain, tenderness, and range of motion. Muscle strength and joint stability will also be evaluated.

They will order X-rays to evaluate for joint space narrowing and associated bony changes. An MRI may be useful to assess the surrounding structures, such as the rotator cuff. A CT scan may be necessary to evaluate the shape and alignment of the shoulder bones, and it is often used for pre-surgical planning. Blood tests may also be ordered to rule out other types of shoulder arthritis, such as inflammatory or rheumatoid arthritis.

Treatment for shoulder arthritis aims to reduce pain and improve joint function. The approach can vary based on the severity of the condition and the individual’s needs:

Non-surgical Treatments:

• Physical Therapy involves exercises to strengthen shoulder muscles and improve flexibility. These are more useful during earlier stages of arthritis.
• Medications: Pain relievers and anti-inflammatory drugs to manage pain and reduce inflammation. Corticosteroid injections are sometimes used to reduce pain and inflammation, and their effect can last for several months.
• Lifestyle Modifications: Adjustments in daily activities to avoid actions that aggravate pain.

Surgical Treatments:

• Shoulder Replacement (Arthroplasty): In severe cases, shoulder replacement will replace the damaged parts of the shoulder with artificial plastic and metal components. This includes total shoulder replacement (which treats shoulder arthritis) and reverses total shoulder replacement (which treats shoulder arthritis and is useful in specific situations, such as when the rotator cuff is also torn and not reparable).

The choice of treatment depends on various factors, including the patient’s age, activity level, the severity of arthritis, and the condition of the surrounding structures, such as the rotator cuff. Early diagnosis and a tailored treatment plan can help manage the symptoms of shoulder arthritis effectively.