S ixty-five thousand patients undergo total hip arthroplasty (THA) each year in the United States.' The hip is the first joint for which total replacement was attempted, glass mold cup arthroplasty of the femoral head was introduced by Smith-Petersen in 1923. Although initial efforts failed, the development and use of various prosthetic and fixation materials continued. In the 1950s, Charnley developed a low-friction, weight-bearing acetabular component with acrylic cement for fixation. Because studies indicated that the cement was the site of prosthetic loosening, P.A. Ring, in 1968, initiated the use of a prosthesis that did not require cement fixation. However, the high coefficient of friction of the metal on metal components of the Ring implant contributed to loosening.* Research and development through the 1960s and 1970s led to the ceramic implant-a ceramic ball femoral head with metal stem and ceramic acetabular component (Mittelmeier prosthesis). The significant characteristics of ceramic material include tissue compatibility, electrostatic inactivity, and resistance to acid, alkali, and corrosion. In addition, anchoring techniques supportive of bone tissue growth provide high stability. Implant placement may be with or without bone cemenc however, the implant material must have a precise finish and la cement.^ In ceramic hip arthroplasty one or both of the articulating surfaces of the hip joint are replaced. Both the acetabular cup and femoral head of the prosthesis are composed of aluminum oxide ceramic; the femoral stem is a cobalt-chrome alloy (Fig 1). Fixation is achieved through fit, without the use of cement.