Joint disease. Coloured computed tomography (CT) scan of a knee affected by arthrosis (yellow/red, also called degenerative joint disease or osteoarthrosis), viewed from the side. The femur (thigh bone) is at top, the patella (kneecap) is seen at left, and the tibia is at bottom. Arthrosis is a progressive condition causing damage to the cartilage and bones of a joint. It can affect many different joints in the body. Risk factors are obesity, aging and the menopause. Activities involving repetitive movements can also lead to arthrosis. Treatment is with anti-inflammatory drugs and, in severe cases, surgery.