Pathology of the bone-implant interfaces

Joint replacement surgery has a wide clinical application as a successful technique. However, the release of biomaterial in particulate form from various implant components has been implicated as a cause of two major clinical complications: 1)bone lysis with or without aseptic loosening, and 2) dissemination of wear particles to distant sites with adverse local or systemic cellular responses. This review focuses on the analysis of the clinical material obtained at the time of revision operations and its value in identifying the pathological processes taking place within the bone-implant microenvironment. Important issues discussed include the incidence of infection, characterization of wear particles, particle-cell interactions, local histopathological changes that lead to the formation of erosive inflammatory lesions next to the bone, sensitivity reactions, tumor formation, and the induction of inflammatory factors and cytokines that can influence the rate of bone resorption versus bone formation.