Long-term results of cementless hip arthroplasties (Zweymuller)

Aim of the study: The purpose of the study is the evaluation of subjective, clinical and radiological long-term results of cementless total hip replac ements with "Zweymuller" stems and Various cups. Method: 113 of 165 consecu tively implanted "Zweymuller" stems have been examined clinically and radio logically as well as assessed for subjective satisfaction by questionnaire, 26 additional patients were analysed by questionnaire only. Thus, the foll ow-up rate is 85.5% with a mean follow-up period of 8.9 years (range 5-12.2 years) as far as evaluation of subjective information including data on fa ilures is concerned. The follow-up results were rated by the scores of Merl e d'Aubigne and Harris and radiolucent lines on the X-rays were analysed. R esults: 96% of the analized patients stated subjective satisfaction. 101 hi ps caused no or only little pain. The average Harris Hip Score rose from 47 .1 preoperative to 86.8 postoperative, the functional value of Merle d'Aubi gne rose from 4.9 to 10.1 (maximum 12 points). The survival rate of the ste ms after 10 years is 96%, the complication rate is very low. 81% of the ste ms showed a proximal radiolucent line. 3 different kinds of cups were used, 79% of the polyethylene cups and 8% of the titanium cups, respectively, we re loosened or had been explanted at the time of examination. Conclusions: During an observation period of 12 years, the implantation of the "Zweymull er" stem has very successful results. The proximal radiolucent lines should nevertheless cause concerns about the predominantly distal anchoring of th e stem. The long-term survival of the stems is much better than that of the titanium cups.