Fatigue fracture and wear have been identified as some of the major problem
s associated with implant failure of medical devices. The actual in vivo me
chanisms are complex and involve the hostile body environment. The response
of the host tissue to wear debris is a real issue. Fatigue-wear corrosion
and environmental stress cracking are common. Although fatigue fracture and
wear are frequently reported in orthopaedic applications such as hip joint
prostheses, they can be fatal in mechanical heart valves. While it is not
possible to avoid failure, recent work has focused on predictive tools to e
nable more accurate prediction so as to avoid catastrophic failure in vivo.
This paper presents an overview of fatigue fracture problems in metallic,
polymeric and ceramic implant materials, looks at some recent techniques of
testing and discusses the future development of fracture and wear resistan
t biomaterials. (C) 2000 Elsevier Science Ltd. All rights reserved.