Zirconia: the second generation of ceramics for total hip replacement.

Alumina ceramic was successfully introduced into orthopaedic surgery for total hip replacement 20 years ago. Its mechanical properties are currently optimized, and there is a need to develop new ceramics having higher mechanical properties, mainly in tension. Yttrium-oxide partially stabilized zirconia is one of the new ceramics that exhibits much more toughness than alumina. This article reviews the processing as well as the mechanical and biological properties of this new class of materials which are already in clinical use in Europe.