Between October 1986 and November 1987, 208 total hip arthroplasties were performed with use of the cementless Zweymüller stem and a threaded cup in 200 consecutive patients. Of 102 patients (108 hips) who were available for follow-up at a minimum of 180 months postoperatively, eighty-three (eighty-nine hips) had the primary joint replacement still intact. No stem had been revised because of aseptic loosening, but we found various degrees of osteolysis around sixteen (18%) of the implants. The probability of survival of the stem at fifteen years was 0.98 (95% confidence interval, 0.96 to 1.00). The probability of survival of the cup was 0.85 (95% confidence interval, 0.79 to 0.91).
Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.
1 Department of Orthopaedics, Medical University of Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria. E-mail address for A. Grübl: firstname.lastname@example.org
2 Alexandra Kaider, MSc Core Unit for Medical Statistics and Informatics, Medical University of Vienna, Spitalgasse 23, A-1090 Vienna, Austria
3 Florian Gottsauner-Wolf, MD Department of Orthopaedics, General Hospital Krems, Mitterweg 10, A-3500 Krems, Austria