Pathology of the bone-implant interfaces

Joint replacement surgery has a wide clinical application as a successful t echnique. However, the release of biomaterial in particulate form from vari ous implant components has been implicated as a cause of two major clinical complications: 1)bone lysis with or without aseptic loosening, and 2) diss emination of wear particles to distant sites with adverse local or systemic cellular responses. This review focuses on the analysis of the clinical ma terial obtained at the time of revision operations and its value in identif ying the pathological processes taking place within the bone-implant microe nvironment. Important issues discussed include the incidence of infection, characterization of wear particles, particle-cell interactions, local histo pathological changes that lead to the formation of erosive inflammatory les ions next to the bone, sensitivity reactions, tumor formation, and the indu ction of inflammatory factors and cytokines that can influence the rate of bone resorption versus bone formation.