Polyethylene wear in total hip arthroplasty in patient-matched groups. A comparison of stainless steel, cobalt chrome, and titanium-bearing surfaces.

Osteolysis and component loosening secondary to polyethylene (PE) debris are of paramount concern to today's joint replacement surgeon. This retrospective clinical study measures linear wear in 568 implanted total hip prostheses in which three different metals were used as bearing surfaces (307 stainless steel T-28 [Zimmer, Warsaw, IN], 162 cobalt chrome Tr-28 [Zimmer], and 99 nonion implanted titanium Miami Orthopedic Surgical Consultants [Biomet, Warsaw, IN] prostheses) implanted by a single surgeon over an 8-year period. The acetabular component in all cases was nonmetal-backed compression-molded PE, and all components were cemented. Linear wear was measured using the radiographic technique described by Livermore et al. (The effect of femoral head size on wear of the polyethylene acetabular component. J Bone Joint Surg 72A:518, 1990) in which change in acetabular component thickness is determined from serial radiographs. A separate evaluation of this technique confirmed accuracy to within 0.18 mm. Radiographs were also evaluated for femoral and acetabular radiolucencies, femoral subsidence, and osteolysis. Patients were matched for sex, age, weight, and length of follow-up period to eliminate these retrospective variables for comparison of wear. The patient-matched groups consisted of 77 patients from each group (43 women, 34 men) with the following demographics: age, 66 years; weight, 158.9 lbs.; follow-up period, 7.9 years. Results revealed linear wear rates of 0.06 stainless steel, 0.05 cobalt chrome, and 0.08 titanium in the patient-matched groups.(ABSTRACT TRUNCATED AT 250 WORDS)