Six to ten year results of use of the alloclassic hip prosthesis--a multicentre survival analysis]

Aim: This prospective study describes This retrospective multicenter study was undertaken to calculate mid- and long-term survival rates of the cementless Zweymuller/Alloclassi(R) total hip prosthesis. Material and Methods: The rectangular titanium stem and threaded cup have been in use since 1986. The ball head is made of alumina ceramic, the inlay of UHMW polyethylene. Five hospitals in Austria, France and Germany cooperated in the follow-up of 848 patients operated between October 1986 and September 1990 (mean age 62.2 years, 62% women, 38% men, mean patient weight 73.8 kg, body mass index 26.8). 468 patients were followed clinically, 320 patients interviewed on the phone, 29 sent a letter. No information was available concerning the remaining 31 patients. Probabilities of implant survival were estimated with the Kaplan-Meier method. Results: 98 patients (11.5%) had died at a median follow-up time of 81.1 months. The probability of survival at 81.1 months was 98.6% looking at stem and cup. There was no significant association of survival of the prosthesis and patient weight, gender or body mass index. Conclusion: Our results are in accordance with previously published data of smaller series using the Zweymuller/Alloclassic(R) total hip. The survival rate of this cementless rectangular titanium prosthesis for the reported follow-up time compares favorably with contemporary cemented hip prostheses.