Abstract
Aims: Hipsimulator tests with highly cross-linked PE shows excellent results after 20 million cycles. Since March 99 we implanted hips with the Fitmore-Cup, Durasul-Inlay and an anatomical stem. In vivo investigations with 300 hips with highly cross-linked PE are introduced. Methods:. We used three methods to test the highly cross-linked PE in vivo: With Polyware-edge-detection we measured the penetration-rate of the Durasul ball-head.
With electron scan microscopy we measured the wear rate in 5 retrierals.
Histological examination of the periprosthetic tissue in 5 retrievals were done.
Results: 1. The linear penetration rate after 1 year is 0,42 mm and after 2 years 0,096 mm.
2. Surface investigation shows no wear in the 5 retrieval cases.
3. Histological examination revealed extremely low depostion of smallest polyethylene particules.
Conclusions:Now we have 3 years clinical experience with highly cross-linked PE. 3D-penetration results are as expected: we see no significant difference between conventional-PE and highly cross-linked PE (bedding in and creep). Surface investigation confirm the plastic deformation and the wear resistence of highly cross-linked PE. Histological examination shows ultra low depostion of PE particles and confirm the excellent in vitro results with highly cross-linked PE. The clinical investigation will be continued.
Theses abstracts were prepared by Professor Dr. Frantz Langlais. Correspondence should be addressed to him at EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
