Arthritis is a complex family of musculoskeletal disorders consisting of more than 100 different diseases or conditions that can affect people of all ages, races and genders. Arthritis is not just a disease of old age. Two-thirds of people with arthritis are under the age of 65, including 300,000 children.
Osteoarthritis (OA), the most common form of arthritis, is a progressive degenerative joint disease characterized by the breakdown of joint cartilage associated with risk factors such as obesity, joint injury, overuse of the joint, weak thigh muscles, genetics and age.
OA is a chronic condition in which the material that cushions the joints, called cartilage, breaks down. This causes the bones to rub against each other, causing stiffness, pain and loss of joint movement. The cause is not fully understood. Osteoarthritis gradually worsens with time, and no cure exists. But osteoarthritis treatments can slow the progression of the disease, relieve pain and improve joint function.