Radiographic demarcation of the acetabular bone-cement interface. The effect of femoral head size.

Abstract

Between 1983 and 1988, 182 total hip arthroplasties were inserted using modern cement techniques including metal-backed acetabular components. Femoral head size was 32 mm in 84, 22 mm in 98. Radiographic analysis revealed three-zone demarcation of acetabular bone-cement interface in 56% of the 32 mm group as compared to 5% of the 22 mm group at 19 and 24 months mean follow-up period, respectively. When a subgroup of women under 60 years of age was created to control variables, the high-grade demarcation rates were 67% and 18%, respectively. Although Charnley hip scores remain similar between the two groups, these results emphasize the adverse effects of large femoral head prostheses on cement-bone interface and underline the need for alternative methods of fixation.