Rheumatoid arthritis most commonly affects the small joints of the hands and feet; in fact, misshapen fingers that make many everyday tasks nearly impossible are one telltale sign of advanced rheumatoid arthritis. But this chronic inflammatory disease can also strike the joints in the neck, shoulders, elbows, hips, knees, and ankles. It usually affects both sides of the body in a symmetrical fashion. Affected joints often swell, feel warm and tender, and may be especially stiff and painful when you wake up or after you rest. Rheumatoid arthritis is much less common than osteoarthritis, affecting about 1.5 million Americans, about 70% of them women.
The disease is widely considered to be an autoimmune disorder, meaning the body's immune system goes awry and mistakenly attacks its own organs or tissues. There's some evidence that certain genes may make people more likely to have the disease, which can run in families. Some researchers believe that rheumatoid arthritis may be triggered by an infection. While there is no proof of this, it's possible that for some susceptible people, exposure to a common infection may spur an abnormal immune reaction.
In rheumatoid arthritis, the immune system attacks the synovium, which then releases enzymes that destroy nearby cartilage. This causes redness, pain, and swelling. Eventually, the joints become enlarged, which hinders normal movement. Your fingers may swell and appear sausage-shaped, and you may develop a soft, lumpy mass over the back of your hand. You may hear a creaking sound (called crepitus) when you move your fingers.
Over time, the ligaments and tendons that hold bones in place stretch and weaken, causing your bones to become misaligned. The MCP joints are often affected. Your fingers may shift away from the thumb, a problem known as ulnar drift. The pain and deformity can be quite debilitating. You may find it hard to hold a cup, tool, or eating utensil. Other daily tasks such as combing your hair and buttoning your shirt can be challenging. (See "Getting a grip: Handy gadgets and advice" for tips on coping with these limitations.)
Inflammation from rheumatoid arthritis can cause the tendons to swell and rupture, resulting in permanent bending of the fingers. One condition is called a boutonniere deformity, from the French word for buttonhole, so named because it involves a small tendon tear that resembles a buttonhole. Another is a swan-neck deformity, in which the middle joint of the finger (the PIP joint) hyperextends.
Because DMARDs have proven so successful in keeping rheumatoid arthritis at bay, hand surgeons have seen a decline in the number of patients who need surgery. But for those whose symptoms become debilitating despite medical therapies, surgery is an option. Surgery for rheumatoid arthritis strives to reduce pain and improve function, and can also improve the appearance of your hands. Soft tissue removal (synovectomy, tenosynovectomy) involves removing diseased tissue from the tendons and joints. The surgeon may also reposition some tendons and release others to stop the fingers from drifting toward the little finger. Although synovectomy can decrease pain and swelling and slow joint destruction, the condition often recurs. Increasingly, surgeons are replacing wrist joints (and in some cases, MCP and PIP joints) destroyed by rheumatoid arthritis.