Abstract
Aim. The aim of this study is to estimate the medium-term results with the Zweymueller metal-on-metal THA in the osteoarthritis of the hip.
Material & Methods. A total of 266 consecutive patients, received 350 third-generation Zweymueller-SL total hip arthroplasties with metal-on-metal articulation for primary or secondary osteoarthritis. The age of the patients at the time of surgery was 55+9 years, (range 25–70 years). Seven (3%) patients did not return for their last follow-up evaluation and they excluded.
Results. The mean follow-up was 67 months (range 49–102 months). The preoperative Harris hip score was 45±19 and increased to 87±4 postoperatively. The invalidity of the patients was significantly improved postoperatively (p< 0.001). In all, 97% of the patients were satisfied or very satisfied with the result of the operation. There was no aseptic loosening noted in this series. Revision was done in 6 (1.8%) hips because of septic loosening (n=5, 1.5%) or technical error (n=1, 0.3%) during implantation. Dislocation of the prosthesis occurred in the early postoperative period in 2 (0.6%) hips because of technical errors during implantation. Periarticular ossification was observed in 30% of the hips (5% Brooker grades III and IV), but without associated disability. During revision surgery, no macroscopic metalosis could be identified in the newly formed hip joint membrane; how ever microscopic evidence for metalosis (Mirra grades 1 and 2) was seen in all revised hips. The survival for Zweymueller screw socket and stem 7.6 years after implantation was 99.4% and 96.8%, respectively.
Conclusion. The reasons of the loosening of Metal-on-Metal Zweymueller THA were the infection or the technical errors during implantation of the socket and nothing about the metal-on-metal articulation.
The abstracts were prepared by Eleni Koutsoukou. Correspondence should be addressed to him at the Hellenic Association of Orthopaedic Surgery and Traumatology (HAOST), 20, A. Fleming str, 15123 Marousi, Athens, Greece.
