MIDDLE-TERM RESULTS OF THREADED ACETABULAR CUPS - HIGH FAILURE RATES 5 YEARS AFTER SURGERY

We report our results using three different threaded acetabular compon ents (Mecring A, Mecring B and Weill) in 715 hips with a follow-up of between one and ten years (median: 99.1, 56.5, 38.3 months, respective ly), All cups were implanted with one type of cementless stem. The cli nical results were good or acceptable in about 70% of the hips, but si gns of loosening with radiolucency and/or migration were found in 10.1 %. Radiological evidence of loosening did not correlate significantly with the clinical outcome, Pain was not a reliable indicator of loosen ing and its sometimes allowed severe osteolysis to Twenty-five hips we re revised (3.5%) for aseptic loosening of the acetabular component, K aplan-Meier estimates of the cumulative rate of failure showed a rapid increase five years after the initial operation, but no significant c orrelation with gender, age or weight. The high rate of failure indica tes that further use of these acetabular components cannot be recommen ded, Annual radiographs are required to assess osteolysis even if the patients are free from pain.