Osteoarthritis is a condition in which the cartilage that protects and cushions the joints breaks down over time. Eventually, the bones—formerly separated by the cartilage—rub against each other. This results in damage to the tissue and bone and causes painful joint symptoms.

Osteoarthritis, sometimes called degenerative joint disease or osteoarthrosis, is the most common form of arthritis. It most often affects the joints of the spine, fingers, thumbs, hips, knees, or toes.