Experimental models in the investigation of device-related infections.

There has been an increasing concern with the problem of device-related infections, ever since foreign materials such as metal or plastic began to be used in implant surgery. The prophylaxis and treatment of such infections is difficult to evaluate in clinical studies, because placebo-controlled prophylaxis trials are thought to be unethical, and no single centre has enough patients for comparative treatment studies. For this reason different experimental models have been developed to study aspects of device-related infections. In this review, these infection models are presented. Different applications of the tissue-cage guinea pig model are summarized. This model allows the study of pathogenesis, natural course, prophylaxis, and treatment of device-related infection. In addition, by using this infection model, novel microbiological in-vitro tests could be developed, and questions of biocompatibility analysed.