In August 2010, DePuy issued a voluntary recall of our ASR™ Hip System. The DePuy ASR™ Hip Replacement devices are metal-on-metal hip replacement systems. The natural hip joint is like a ball that fits in a socket. The socket portion of the hip is called the acetabulum. The femoral head at the top of the thigh bone (femur) rotates within the curved surface of the acetabulum. According to DePuy, the recalled hip DePuy ASR™ hip implants utilize a one-piece acetabular cup, which is a metal liner that replaces the acetabulum. With the recalled DePuy ASR XL Total Hip Replacement System, there are three components: 1) The femoral stem is inserted inside the femur 2). The femoral head (or ball) connects to the stem, and 3). The stem then fits inside the acetabulum.
The ASR device does not use cement to attach the metal parts to the bone; rather it relies on bone growth to fasten the hip replacement parts to the bone. It is believed that this design is flawed and increases the likelihood of the hip replacement loosening and may cause a number of painful symptoms for the patient. The symptoms are swelling, pain and even difficulty walking. Persistent symtoms can signal a loose implant, fracture of the bone around it or dislocation of the implant’s ball and socket.