Wear Testing of Total Hip Joints According to Iso and Development of a New Hip Joint Simulator According to Iso

INTRODUCTION The development of new, highly sophisticated materials for the articulating surfaces of total hip endoprostheses has led to an increasing demand for testing and verification. This includes tests and research regarding bio-compatibility, static load bearing capacity of the prostheses as well as tribological investigations. Since it has been found that wear debris play a dominant role in the osteolytic loosening of implants, wear testing becomes especially important with new materials being developed to prolong the service life of an endoprostheses. The wear resistance of materials utilized for endoprostheses has been tested by the use of wear simulators for decades at laboratories throughout the world [1]. As a consequence of widely diverging test methods being in use, the technical committee TC150 'Implants for Surgery' of the ISO (International Organization for Standardization) has aimed to develop an International Standard, ISO/FDIS 14242: Implants for surgery wear of total hip joint prostheses on the basis of kinematics and kinetic data from gait-analysis and a method of assessment of wear. This new standard will constitute a base for the comparability of scientific data resulting from tribological testing of total hip endoprostheses. The first experiences with the newly developed hip simulator E-SIM using common material pairings in total hip arthoplasty give promising results both in the characteristics of wear and the amount of removed material. A inter-laboratory validation of wear simulation with the E-SIM Hip Simulator is currently performed.