Composite Metal/Ceramic Bearings for THA Implants

DESCRIPTION (Provided by Applicant): The implications of developing materials
with enhanced fracture toughness, damage resistance, reliability and ultra low
wear is of significant interest to the orthopedic community, since it directly
addresses a vital clinical concern- eliminating wear debris mediated THA
implant failures. In Phase I we made a significant step towards addressing this
central issue by successfully demonstrating a novel ceramic material with
superior mechanical properties. An enhancement of 50 percent in fracture
toughness, 50 percent in weibull modulus and significant damage resistance over
conventional ceramics was demonstrated. Thus, we have been able to establish
materials which, from a safety and design aspect, will have significantly lower
risk of brittle failure in vivo. Furthermore, we have been able to adpat the
ceramics for articulation with CoCr. From a bio-compatibility aspect, no
adverse effects are expected in-vivo. Early wear performance results of
head/cup components made from these ceramics also clearly show the ultra low
wear characteristics, with wear volumes 2-3 orders of magnitude lower than
present CoCr-PE. In Phase II, we propose to extend these promising results by
optimizing the component design tolerances using a rigorous statistically valid
approach, characterizing the static and fatigue strength of THA implant
components, and performing a comprehensive in-vitro and invivo
bio-compatibility evaluation. We also propose to extend the wear tests (n=6) to
10 million cycles in a hip simulator to confirm the functionality of the
optimized components. Major orthopedic implant manufacturers have expressed
interest in collaborating on the evaluation and optimization of the novel
ceramic designs.

PROPOSED COMMERCIAL APPLICATION:
The combination of safety (mechanical and biological) and function (ultra-low wear) and compatibility with CoCr offers a new bearing materail set that promises to eliminate the central issue plaguing THA - wear debris mediated osteolysis and implant failures. A comprehanesive program to establish the safety and function of the materials will help speed the commercialization of these implants in Phase III.