Poor results of the Freeman uncemented metal-backed acetabular component. Five-to-nine-year results

We reviewed 120 consecutive primary total hip replacements in 109 patients in whom a Freeman uncemented metal-backed component had been used. Acetabular components were used with a Freeman neck-retaining stem in one of three configurations: cemented smooth stem, uncemented smooth stem or uncemented ridged stem. After a mean follow up of 72 months (62 to 113) there were nine cases of aseptic loosening; a survivorship at eight years of 83%. In addition, more than one-third of the remaining surviving cups showed loosening radiologically. The Freeman acetabular component demonstrated a characteristic pattern of loosening on radiographs. The high incidence of aseptic loosening can be explained by poor design and material failure.