We carried out 71 primary total hip arthroplasties using porous-coated, hemispherical press-fit Duraloc ‘100 Series’ cups in 68 consecutive patients; 61 were combined with the cementless Spotorno stem and ten with the cemented Lubinus SP II stem. Under-reaming of 2 mm achieved a press-fit. Of the 71 hips, 69 (97.1%) were followed up after a mean of 2.4 years. Migration analysis was performed by the Ein Bild Röntgen Analyse method, with an accuracy of 1 mm.

The mean total migration after 24 months was 1.13 mm. Using the definition of loosening as a total migration of 1 mm, it follows that 30 out of 63 cups (48%) were loose at 24 months.

We performed revision surgery for infected arthroplasty in 98 hips (96 patients). In 28 hips infection persisted. Of the remaining 70 hips, 61 (87%) were reviewed after a mean interval of 5.9 years (1 to 17). Infection occurred in 10% of these after three years and in 26% after ten years. The infection rate after initially successful revision for septic arthroplasty is higher than after revision for aseptic loosening and the risk of developing infection continues for many years.