Peri-implant pathology--relation to implant failure and tumor formation.
Despite the clinical effectiveness ofjoint replacement arthroplasty, a number of complications, most of which present clinically with signs and symptoms related to implant loosening, are associated with this procedure. Histological changes that occur in soft tissue and bone around an implant provide diagnostic information on the causes of implant loosening and give clues as to the nature of the pathological processes that lead to this and other complications of implant-related joint disease. These pathological processes include the biologically nonspecific body macrophage response to wear particles (aseptic loosening), a specific hypersensitivity immune reaction to implant-derived wear particles, infection (septic loosening), primary joint-related pathology in revision arthroplasty tissues, and tumor formation in peri-implant tissues. This review outlines pathological changes that reflect pathogenetic mechanisms contributing to implant loosening and other complications in peri-implant tissues.