Osteoarthritis. X-ray of the hip joint of a 65- year-old woman with osteoarthritis. The head of the femur (centre) is almost indistinguishable from the pelvis. A normal joint would have a clear space between the ball of the femur and the socket of the pelvis. Osteoarthritis causes the cartilage between bones to break down, resulting in bones rubbing together. It is a common but painful joint disease that affects most people over the age of 60, although more women than men are affected. There is no cure, although symptoms can be relieved with painkilling & anti-inflammatory drugs, sever cases may require hip replacement surgery.