Degenerative joint disease, which is also referred to as osteoarthritis (OA), is a common “wear and tear” disease that occurs when the cartilage that serves as a cushion in the joints deteriorates. This condition can affect any joint but is most common in knees, hands, hips, and spine.Arthritis involves the breakdown of cartilage. Normal cartilage protects a joint and allows it to move smoothly. Cartilage also absorbs shock when pressure is placed on the joint, such as when you walk. Without the normal amount of cartilage, the bones under the cartilage become damaged and rub together. This causes swelling (inflammation), and stiffness.