Selected Examples of Pathologic Processes Associated with Human Polymeric Implants

Abstract

Continuing advances in the design of prostheses and techniques for their implantation have produced impressive results in the length and quality of survival in patients who receive these polymeric prostheses or devices. With the ever increasing number of implants over the past two decades, basic and clinical scientists have used a wide and varied number of techniques to appreciate or determine the suitability of a given polymer for a given implant application. These techniques, aimed at determining the implant/host interaction, have generally been included under the term “biocompatibility”. Investigators commonly deal with biocompatibility in terms of whether the implant material or its degradation products, if any, initiate adverse tissue responses in the host or conversely whether deleterious changes in the chemical, physical and/or mechanical properties of the implant material are caused by the host environment. The vast majority of fundamental studies of biocompatibility involve animal models. The ultimate test for biocompatibility of a polymer, device or prosthesis, is human implantation. With this in mind, we have sought to examine implants and tissue obtained by surgical removal from humans or at autopsy. The simultaneous examination of polymeric implants and tissues removed from humans offers an opportunity to directly appreciate the various aspects of the implant/host interaction.