title: New method for determining in vitro structure stiffness of ceramic acetabular liners under different impact conditions.
abstract: 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.
authors.affiliation: Department of Orthopaedic Surgery, Klinikum Rechts der Isar, Technical University Munich, Munich, Germany. eichhorn@tum.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Eichhorn
authors.forename: Erwin
authors.initials: E
authors.lastname: Steinhauser
authors.forename: Reiner
authors.initials: R
authors.lastname: Gradinger
authors.forename: Rainer
authors.initials: R
authors.lastname: Burgkart
mesh_terms: D000077:Acetabulum; D000537:Aluminum Oxide / Q000737:chemistry; D002516:Ceramics / Q000737:chemistry; D006622:Hip Prosthesis; D006801:Humans; D008422:Materials Testing / Q000295:instrumentation / Q000379:methods*; D013314:Stress, Mechanical; D015040:Zirconium / Q000737:chemistry
chemical_list: D015040:Zirconium; D000537:Aluminum Oxide; C028541:zirconium oxide