What is the difference between osteoarthritis and rheumatoid arthritis?

These two conditions are quite different.

Rheumatoid arthritis is an autoimmune condition, meaning that the affected person’s overactive or misguided immune system appears to be responsible for the disease. Immune cells attack the joints and other parts of the body, causing joint damage and bodywide inflammation. It’s much more common in women and most commonly begins during middle age. Multiple joints are affected, especially those in the hands, wrists, knees and feet. Of note, the joints linking the fingers to the hand (called the metacarpal-phalangeal, or MCP, joints) are characteristically affected. Prolonged morning stiffness is common, often lasting more than 30 to 60 minutes. The affected joints may be warm, swollen and have limited motion. Autoantibodies, called rheumatoid factor and anti-cyclic citrullinated protein, are found in the blood of most people. X-rays demonstrate a particular type of damage (called “erosions”) at the edges of the joint with reduced bone thickness. Treatment generally requires anti-inflammatory and immunosuppressive medications.

 

By contrast, osteoarthritis is considered a degenerative joint disease due to age-related “wear-and-tear.” Women develop osteoarthritis more often than men but the difference is much smaller than with rheumatoid arthritis. Osteoarthritis is not autoimmune in origin and it is not a cause of bodywide inflammation. It usually affects the finger joints (but not the MCPs), hips, knees, feet, upper and lower spine. The joints have far less inflammation by examination and bony enlargement is apparent, especially in the fingers. Morning stiffness is usually quite brief (less than 30 minutes) and there are no arthritis-related autoantibodies in the blood. X-rays may demonstrate narrowing of the affected joints with extra bone formation at the edges. Medication treatment focuses on pain control rather than suppressing the immune system.

 

While they are quite different, there are some similarities: the loss of joint mobility may lead to loss of function and difficulty with everyday activities. Physical therapy and exercise are recommended in both conditions. Joint replacement surgery may be necessary in either condition if the joint damage is sufficiently severe.