Osteoarthritis of the Shoulder
Shoulder OA is more common and debilitating than you may think.
Your shoulder has three bones that come together to create two separate joints. The acromioclavicular (AC) joint is formed where your collarbone (clavicle) meets the bony tip of your shoulder blade (acromion). The glenohumeral joint forms where the head of your upper arm bone (humerus) fits into your shoulder blade (scapula).
In shoulder osteoarthritis (OA) – also called degenerative joint disease – your cartilage and other joint tissues gradually break down. Friction in the joint increases, pain increases, and you slowly lose mobility and function. Shoulder OA is not as common as OA of the hip or knee, but it is estimated that nearly 1 in 3 people over the age of 60 have shoulder OA to some degree. OA is more common in the AC joint than the glenohumeral joint.
Causes of Shoulder OA
Shoulder osteoarthritis can be either primary or secondary.
Primary OA has no specific cause but is related to age, genes and sex. Primary OA is usually seen in people over the age of 50, and women are affected more often than men.
Secondary OA has a known cause or influencing factor, such as previous injury, history of shoulder dislocations, infection, or rotator cuff tears. Having certain occupations -- such as heavy construction – or participating in overhead sports can also put you at higher risk of developing shoulder OA.
Symptoms of Shoulder OA
Pain is the most common symptom of shoulder arthritis. Pain is aggravated by activity and gets worse over time. As the disease progresses, the pain will continue when you are at rest and will begin to interfere with sleep.
- If the glenohumeral shoulder joint is affected, the pain will be felt at the back of the shoulder and may feel like a deep ache.
- If the AC joint is affected, pain will be focused on the top of the shoulder. This pain may radiate up the side of the neck.
Limited motion and stiffness are other common symptoms. You may lose range of motion so that you can’t lift your arm to wash your hair or get something down off a shelf.
Crepitus is when you hear and feel grinding and clicking noises as you move your shoulder.
Diagnosing Shoulder OA
To diagnose shoulder OA, your doctor will ask about your symptoms and medical history. During the exam she will look for:
- Muscle strength
- Tenderness to the touch
- Mobility – both active and passive range of motion
- Signs of new or old injuries
- Other joints with signs of arthritis
- Crepitus (a grating sensation inside the joint) with movement
- Pain in certain positions
- Swelling or joint enlargement
After the physical exam, your doctor will likely order X-rays. If you have OA, they will show joint-space narrowing, changes in the bone, and the formation of bone spurs (osteophytes).
Treatments for Shoulder OA
Osteoarthritis is a chronic disease. There is no cure, but treatments can help manage your symptoms and keep you active.
If you have shoulder OA, start with the basics of self-care to manage your symptoms.
- Change your activities. You may need to alter the way you move your arm to avoid pain.
- Do physical therapy and rehab exercises. Stretch and strengthen the muscles that support your shoulder to reduce stress on the joint. These exercises may also improve your range of motion.
- Try heat or cold. Apply an ice pack for 20 minutes two or three times a day to reduce inflammation and ease pain. Or wrap your shoulder in a warm, wet towel or a heating pad to soothe your joint and improve mobility.
- Seek complementary treatments. Acupuncture, massage, or yoga may help improve mobility and pain.
Medicines to ease OA symptoms are available as pills, syrups, creams or lotions, or they are injected into a joint. They include:
- Pain relievers like acetaminophen and anti-inflammatories like nonsteroidal anti-inflammatory drugs (NSAIDs) can be used to ease pain.
- Topical analgesics such as NSAID gels, capsaicin or counterirritants can be rubbed into the shoulder to reduce pain.
- Corticosteroids are powerful anti-inflammatory medicines that can be injected into the shoulder joint. An injection can dramatically reduce inflammation and pain, but only helps temporarily.
You and your doctor may consider surgery if your pain and mobility are not improved with physical therapy and medicine.
Arthroscopy can be used to clean out the inside of the joint, removing bone spurs and loose pieces of cartilage. Arthroscopy provides pain relief, but it will not eliminate your arthritis.
Joint replacement (arthroplasty) can be done if you have advanced arthritis in your glenohumeral joint. In this, the head of the humerus is replaced with an artificial “ball” and the glenoid cup is replaced with a synthetic part. In hemiarthroplasty, just the head of the humerus is replaced, but the cup is left alone.
Resection arthroplasty is used to treat advanced OA of the acromioclavicular (AC) joint. In this procedure, a small piece of bone from the end of the collarbone is removed. That space will gradually fill with scar tissue.