Osteoarthritis (OA) is the most common form of arthritis. It is also known as degenerative joint disease (DJD).

Normally, cartilage covers the ends of each bone where they form a joint, helping the joint to move smoothly. In OA, cartilage breaks down. This breakdown can cause pain, stiffness, and swelling of the joint. OA can affect any joint, but is most common in knees, hips, the lower back, neck, small joints of the fingers and the bases of the thumb and big toe.

By age 85, nearly 50% of people may develop painful knee OA and nearly 25% of people may develop painful hip arthritis. Osteoarthritis is more common in women than men, especially after age 50. Men have 45% lower risk of knee OA and 36% reduced risk of hip OA than women.

OA is a chronic (long-term) disease. While there isn’t a cure, several treatment options are available to help manage symptoms.