Evaluation of the compatibility of ceramic ball head and femoral stem taper on the new type THR

摘要

Purpose: of this paper was follow up of compatibility of femoral component taper from TiAl6V4 ELI acc.ISO5832-3 and ceramic head of the new type of total hip join replacement THR - ZRM.in vitro.Design/methodology/approach: from december 2006 to august 2007 we have tested THR taper component and ball ceramic head. On the base of our patents ( SK, CZ, EU, USA) from 1999 to 2006 we have designed and developed the new type of cementlesss THR - ZRM.. These total hip replacements were tested in our prospective study. We have evaluated compatibility and loading resistance of taper of THR ZRM.made from TiAl6V4alloy ELI and ceramic ball head Biolox.forte (28-12/14L) by tests of burst strength, pull out, rotational stability, fatigue and post-fatigue. Tests were monitored independent observer.Findings: in the burst test were tested 7 parts and average loading was 54 kN. The reached values comply with the requirements according to CeramTec procedure VA 02 04 4129 and the FDA Guidance document for the preparation of premarket notifications for ceramic ball hip systems. In the fatigue test all specimens test at a maximum load of 14 kN reached 10 million cycles without mechanical failure. The post fatigue test was performed with load of 46 kN and no failure of head and taper system was observed. The pull-off tests were made with pull out strength of 1439 N has been used on 5 parts and no pullout of ceramic ball head of taper femoral component was observed. Last was the test of rotational stability, where ball head was rotational stable under strength of 1254 Ncm.Research limitations/implications: this study was performed on the small group of spices but enough relevant according FDA and international ISO prescriptions.Originality/value: this study is original by publishing first results of the new cementless THR- ZRM.tests of compatibility and fatigue of metal taper and ceramic ball head. Value of this paper is in vitro testing and prepares ZRM.cementless THR for clinical use in human