Midterm experience with the cementless Zweymueller system. Results of a minimum five-year follow-up study

Eighty-five patients with 96 cementless press-fit hip implants were followed over a period of at least 5 years postoperatively. The average Harris score was 87.5 points. One socket had to be exchanged 4 years postoperatively because of aseptic loosening. Additionally, 5 sockets developed radiolucent lines, one of them totally around the socket, but without signs of subsidence progression. In no case was a change of the stem necessary; one stem subsided 4 mm within the first postoperative year but was stable at the last follow-up investigation. One patient was personally dissatisfied with the outcome of the operation. No implant-specific complications such as breakage of the implant, breakage or crack of the stem, or blasting of the pelvic girdle by socket-screwing were observed.