[Changes in shape of the McKee-Farrar hip endoprosthesis]

The still unsolved problem of aseptic loosening in total hip arthroplasties with identification of polyethylene wear particles as one of its major causes, has led to reintroduction of metal-to-metal articulations, as indicated by a few good clinical long-term results with all-metal McKee-Farrar arthroplasties. In this paper, data on 145 patients from a population of more than 1400, all with implanted McKee-Farrars, who underwent revision surgery for aseptic loosening, are collected and analysed for dependence of duration to brands of the implants and position of the cups. The surface of each of 55 revised implants was measured using a 3-D device. The results showed no interdependence between time of loosening, brand inclination of the cup and deviation in shape of ball and cup. Additionally, the deviations in shape were slight.