Osteoarthritis (also known as OA, degenerative arthritis, degenerative joint disease, osteoarthrosis) is a joint disease caused by
cartilage loss in a joint. Osteoarthritis is the most common form of arthritis, especially in older people. Osteoarthritis causes joint stiffness and pain due to the wearing down of the cartilage on bones that allows the bones to rub on each other. As time passes, the joint loses shape and may even develop bone spurs which causes even more pain.