Papers by Author: Claudia Ortmann

Abstract: In the present investigation, three ceramic-ceramic-couplings (alumina - alumina) were examined for possible reasons of the squeaking noise which occurred after surgery. Under certain conditions like, for example, a suboptimal position of the implant and corresponding soft tissue relations, a subluxation or microseparation of the ceramic head from the ceramic liner may occur; this, in turn, may lead to a squeaking noise of the joint. Apart from the psychological stress for the patient due to the awkward noise and the resulting feeling of instability, the squeaking noise is a sign for damages on the implant in most cases.

Abstract: Abstract. A new ceramic material for orthopaedic applications was investigated. Therefore a gradient ceramic was prepared with a zirconia gradient within an alumina matrix by an infiltration process. This material was characterized regarding its microstructure, stress distribution inside the ceramic, zirconia phase analysis and strength. It could be shown that the flexural strength of the new ceramic is twice as high as of pure alumina ceramic. By this and the low monoclinic zirconia content this material offers a potential for its use in high load bearing implants like hip heads for joint endoprostheses.