Technical considerations of cemented acetabular components - A 30-year evaluation

The effect of porosity reduction cementing techniques with respect to radio lucent lines in Zone 1 and failure in acetabular components was studied in 2237 consecutive cemented acetabular components done between 1970 and 1998. The minimum followup was 2 years. Radiolucencies in Zone 1 on initial radi ographs obtained postoperatively were tabulated for five groups of patients based on cementing techniques. The percentage of loose or revised cups was calculated far six groups based on type of prosthesis used. The lowest per centage of Zone 1 radiolucencies was in a group in which bowl mixing was us ed. The lowest failure rate was in the group that received Charnley prosthe ses in which simple first generation cement techniques were used. Porosity reduction techniques did not reduce the incidence of Zone 1 radiolucencies. For the acetabular side of a total hip replacement, the biology of the bon e and the techniques of cement insertion that include a dry cancellous bone bed, perforation and removal of peripheral sclerotic areas, pressurization of the entire cement mantle in the socket at one time, and complete buryin g of the acetabular component within the boundary of the bony acetabulum ar e the essential factors, not porosity reduction in the cement.