Orthopedic implant retrieval and failure analysis

Orthopedic devices make up a major percentage of the medical devices being implanted today. Success rates exceeding 95% have been reported. However, their longevity is compromised by fatigue, wear, corrosion, and other degradative mechanisms. Adverse biologic responses to products from these different mechanisms can lead to significant bone loss and may even compromise subsequent surgeries. It is imperative that we fully understand what mechanisms are in play and carefully evaluate strategies to minimize, if not eliminate, these degradation processes. Devices retrieved at revision surgery and at autopsy have provided us with important information regarding the performance of orthopedic implants. Surface characterization of the implant, biomechanical analyses, and histological analysis of the tissues surrounding the implant can provide us with information not available through other sources. This chapter will review the significance of retrieved implants to the long-term survival of these implants.