[Septic loosing of hip and knee prosthesis].

Loosening of an artificial joint is a common complication in orthopedic surgery. It is estimated that bacteriological implant contamination is responsible for its loosening in 2-5 percent of cases, and in most cases aseptic loosening takes place. Despite low percentage of positive microbiological studies, histopathological examinations and modern laboratory techniques, including PCR (Polymerase Chain Reaction) allow to diagnose the bacterial contamination of the loose implant to ca 70 percent. Those observations point out to the high coincidence of bacterial contamination with implant loosening strongly suggesting its influence on activation of the inflammatory process destabilizing an implant. But the question, why in those cases bacterial contamination does not lead to clinically obvious suppuration, remains unknown. The possibility to activate the immune system by the subcellular elements of the bacterial cells leading to persistent inflammation with granulation tissue formation is likely. Presented paper discusses the process of orthopedic prosthesis loosening, the role of bacterial contamination in it. and the newest techniques for their examination.