New ceramics and composites for joint replacement surgery

Ceramics have been used as an alternative to metal-on- polyethylene in joint replacement surgery of arthritic hips and knees since the 1970s. In prosthetic hip and knee bearings, ceramics offer a major benefit of drastically reduced wear rates and excellent long-term biocompatibility, which can increase the longevity of prosthetic hip and knee joints. This benefit is important clinically because hip and knee replacements have become very common surgical procedures, particularly in the United States and Europe, and because these procedures are increasingly performed in younger patients who place greater demands on the prosthetic bearings. Modern ceramic bearings are safe and reliable if used with components of proven design and durability. However, catastrophic bearing failure in vivo, while rare, and the risk of 'squeaking' (audible noise) of ceramic bearings, while low, have served to diminish the enthusiasm of many patients and orthopedic surgeons for ceramic bearings in total joint replacement. Future material improvements are actively being investigated to reduce the risk of ceramic bearing failures even further, and to extend the range of ceramic bearing components available for total joint replacement. In this chapter, the properties, applications, and limitations of ceramics that have been used in orthopedic bearings are reviewed, and the new ceramics and composites that will be available for joint replacement surgery in the near future are discussed. © 2011 Woodhead Publishing Limited All rights reserved.