Survivorship Analysis of Cemented High Modulus Total Hip Arthroplasty

Abstract

Ninety-four high-modulus total hip arthroplasties (THAs) were performed from 1977 to 1982 using the Computer Assist Design (CAD) and HD-2 prostheses. Eighty-six hips were followed for an average of 6.7 years. The cement gun was used throughout the study period, and distal bone or cement plug use was begun in 1979. The results of these arthroplasties were evaluated retrospectively using both survivorship analysis and observed success rates. Using a standard hip rating system, 19 hips were rated as excellent, 44 as good, 15 as fair, and 11 as poor. Failure was defined as definitely visible radiographic migration of either component, or reoperation for revision of one or both components. There was no significant difference between the HD-2 and CAD prostheses. There were five hips revised for aseptic loosening and revision was advised in an additional three hips. One hip with late sepsis required removal of both components. The five- and ten-year survivorships of the acetabular components were 97% +/- 3 and 58% +/- 17, respectively. Those of the femoral components were 93% +/- 5 and 78% +/- 13, respectively. For the components combined, the survivorship at five years was 91% +/- 6 but only 50% +/- 17 at ten years. Survivorship analysis provided a different and more realistic appraisal of the long-term results of the arthroplasties in this series than did the observed success rates. The contemporary cement techniques of the late 1970s and early 1980s may not be sufficient for the long-term survival of high-modulus THAs. Additional techniques may be necessary for improved long-term survival.