Hip joint osteoarthritis. Coloured Xray of the pelvis of a 72yearold woman showing areas of osteoarthritis of the hip joints (red). The ball andsocket joints of the two femurs (upper leg bones, lower left and right) are usually smooth in appearance and the ball of the femur is separated from its socket in the pelvis by frictionreducing cartilage. Here, osteoarthritis has caused the cartilage to wear away, causing the joint space to become narrowed in places with erosion of the bone. The joints stiffen and get painful. Osteo arthritis is common in people over the age of 60 with more women than men suffering. Symptoms can be relieved with antiinflammatory drugs, although hip replacement surgery may eventually be necessary.