Osteoarthritis (OA) is the most common type of arthritis, also known as degenerative joint disease, for which there is no cure. It is a common, chronic, progressive musculoskeletal disorder.
In an osteoarthritic joint, the surface layer of cartilage gradually breaks down and wears away. The bones in the joint that are now exposed and rubbing against each other, causing pain, swelling, and loss of motion. Over time, the joint may lose its normal shape. In addition, small deposits of bone, called bone spurs, may grow on the edges of the joint. These can break off and float inside the joint space, causing even more pain and damage.