Abstract

A 2-year follow-up study was conducted on 46 patients to assess Harris Hip Scores (HHS) and early distal migration of the femoral stem after total hip arthroplasty using a fully cemented femoral stem. The mean age was 73.4 years . The Fullfix stem (Mathys A.G., Bettlach, Switzerland) is characterised by a mat polished surface and a flange aimed to compress the cement during the insertion process. Early distal migration was determined in 36 patients using the computer assisted EBRA-FCA method (Einzel-Bild-Roentgen-Analyse femoral component analysis). At 2 years, subsidence reached a mean value of 0.44 mm (95%CI : 0.19, 0.70), whereafter the stem appeared stable, i.e. distal migration reached a plateau. Females showed significantly higher migration than males (p < 0.01). EBRA-FCA proved to be an accurate method to measure early migration, with a standard deviation below 1 mm (0.56 mm in the interval 1-2 years). Harris Hip Scores (HHS) at 2 years follow-up averaged 89.6 (95%CI : 79.5, 99.8). As expected considering the small extent of migration, there was no correlation between subsidence and HHS (p = 0.5).