Increasing both patient mobility and prosthesis life span requires improvements in the range of motion and wear behavior of the liner. With the use of new composite alumina-zirconia ceramic materials, the same stability of the liner can be achieved at lower wall thickness than it is possible with alumina-only materials. The aim of this study was developing a method for determining the in vitro structure stiffness of ceramic acetabular liners against impact stresses. The first trials were performed with a common alumina acetabular liner type (Ceramtec; Biolox forte; diameter 28 mm; thickness 7 mm) and a new type of alumina-zirconia (Ceramtec Biolox delta; same dimensions) liner. The clinically established alumina liner was reproducibly damaged using worst case Separation/subluxation equivalent to one-fourth or half of the head diameter, and an impact load of 15 J. The liners containing the new alumina-zirconia material were not damaged in any of the trials up to an impact load of 20 J and half head diameter offset.
Copyright © 2011. Published by Elsevier Ltd.