Les prothèses de hanche en biocéramique sont résistantes à l'usure mais, du fait de leur fragilité intrinsèque, sont susceptibles de se rompre. Le phénomène de décoaptation, séparation de faible amplitude de la tête et de la cupule, a été mis en évidence lors de la marche, et le choc mécanique en résultant peut fortement augmenter les risques de rupture. Un modèle par éléments-finis a été développé et les résultats ont été exploités afin de simuler l'évolution de la probabilité de rupture de cupules en zircone au cours du temps. Les résultats s'accordent bien avec l'expérience, même si des améliorations sont nécessaires afin de prendre en compte l'érosion des surfaces de contact.

This article serves to introduce the January 2004 issue of MRS Bulletin on progress toward applications of ceramic nanostructures. Conventional ceramic materials are widely used today in areas ranging from structural to biological applications, and in devices as diverse as lasers, semiconductors, sensors, and piezoelectric components. Such materials include oxides, carbides, nitrides, mixed oxides, and composites.Over the last decade, the use of ceramic nanostructures has already changed the approach to materials design in many of these applications, by seeking structural control at the atomic level and tailoring of the engineering properties. The articles in this issue review the advantages of nanoceramics, their application in various fields, and the challenges involved in their fabrication.

An improved understanding of the interactions at the nanoscale level between the bioceramics in medical implants and the hard or soft tissues in the human body could contribute significantly to the design of new-generation prostheses and postoperative patient management strategies.Overall, the benefits of advanced ceramic materials in biomedical applications have been universally accepted, specifically in terms of their strength, biocompatibility, hydrophilicity, and wear resistance in articulating joints.The continuous development of new-generation implants utilizing nanocoatings with novel nanosensors and devices is leading to better compatibility with human tissue and improved well-being and longevity for patients. This article gives a short overview of bioceramics and reexamines key issues of concern for processing and applying nanoceramics as biomaterials.