The fate of stable cemented acetabular components retained during revisionof a femoral component of a total hip arthroplasty

Background: The decision as to whether to revise or retain a well fixed cem ented acetabular component during revision of a femoral component is especi ally difficult; the rate of loosening of cemented acetabular components is high, whereas that of porous-coated acetabular components inserted during r evision is low However, removal of a well fixed cemented acetabular compone nt can result in increased operative morbidity and cost and in loss of acet abular bone. Data that can be used to predict the long-term survival of ret ained well fixed cemented acetabular components are therefore needed. Methods: We studied the five to thirteen-year clinical and radiographic res ults in a group of twenty-six consecutive patients in whom a well fixed cem ented acetabular component had been retained during revision of a femoral c omponent. Typical demographic data on the patients and information about th e components were recorded, and the cemented acetabular components were gra ded as A through F, according to the system of Ranawat et al,, at the time of the femoral revision. The average duration of follow-up was 8.4 years (r ange, 5.0 to 12.7 years). No patient was lost to follow-lap. Results: Four acetabular components (15 percent) had progressive radiolucen cy (at forty-eight, forty-eight, fifty-nine, and seventy-fire months after the femoral revision) and were considered radiographically loose despite no t being associated with symptoms.;UI four components were graded as either E or F at the time that they were retained during the femoral revision; rad iographic loosening was significantly related to these two grades (p < 0.01 ), No acetabular component with a grade of A, B, Ct or D loosened. The comp onents that loosened had been in vivo for a relatively shorter, as opposed to longer, duration before the femoral revision compared with the component s that did not loosen (p < 0.05), Conclusions: Retention of the well fixed cemented acetabular components was associated with good clinical results but with a 15 percent rate of loosen ing. Revision of a cemented acetabular component solely on the basis of the duration that it was in vivo or whether a previous revision had been done does not appear to be warranted, Our findings suggest that acetabular compo nents with a grade of A, B, C, or D at the time of a femoral revision may b e retained, as these components continued to function at the time of the fi ve to thirteen-year follow-up in the current study.