Using Ceramic-on-Ceramic Bearings in Total Hip Arthroplasty Necessitating 44-or46-mm Metal Shells

Ceramic-on-ceramic articulation shows the lowest wear, with a low incidence of osteolysis. A small cup limits options regarding liner thickness and femoral implant size. The purpose of this study was to evaluate the safety of a 4-mm-thick ceramic liner and the outcomes of cementless total hip arthroplasty using a 44-or 46-mm metal shell and a ceramic-on-ceramic bearing at mid-to long-term follow-up. Between May 2003 and June 2008, 80 patients (88 hips) who had hip osteoarthritis and a hypoplastic acetabulum underwent cementless total hip arthroplasty using a 44-or 46-mm metal shell and a ceramic-on-ceramic bearing. Sixty-eight of these patients (76 hips) were followed for an average of 8 years. The ceramic-related complications, clinical and radiological results, and Kaplan-Meier survivorship of these patients were evaluated. Mean Harris hip score had improved to 88 points (range, 49-100 points) at final follow-up. No ceramic fractures occurred during follow-up. All acetabular and femoral prostheses had bone ingrowth, and there was no measurable wear in any hip. In 1 patient, a radiolucent lesion occurred around the acetabular cup. Two hips underwent revision because of periprosthetic fractures. The survival rates of the acetabular cups and the femoral stems were 100% and 97.4%, respectively. The thin (4 mm) ceramic liner did not increase the risk of ceramic fracture and did not affect the mid-to long-term results and survival of cementless total hip arthroplasty using 44-or 46-mm metal shells.