cup arthroplasty of the hip joint [L, cupa, cask; Gk, arthron, joint, plassein, to mold] , the surgical replacement of the head of the femur by a metal or plastic mold to relieve pain and increase motion in arthritis or to correct a deformity. The damaged or diseased bone is removed, and the acetabulum and the head of the femur are reshaped. A cup is inserted between the two and becomes the articulating surface of the femur. After surgery the patient’s legs are placed between an abduction pillow to hold them in a position of abduction extension and internal rotation to keep the cup in place in the acetabulum. Continued abduction may be necessary for 6 weeks. Possible complications include infection, thrombophlebitis, pulmonary embolism, and fat embolism. The patient receives extensive physical therapy. A walker or crutches are necessary to prevent full weight-bearing for 6 months, and an exercise program must be followed for several years. Compare hip replacement. See also arthroplasty, knee replacement, osteoarthritis, plastic surgery.
