[Implant-associated post-traumatic osteomyelitis. Bacterial biofilms and the immune defence as protagonists of the local inflammatory process]

Abstract

Background: Formation of bacterial biofilms on implants is a severe complication following orthopaedic surgery. In the present study we addressed the role of the immune response, particularly with regard to the pathogenesis of the disease.

Methods: In a prospective study comprising 74 patients with implant-associated post-traumatic osteomyelitis, peripheral blood cells as well as cells recovered from the infected site during surgery were characterised phenotypically and functionally.

Results: We found massive infiltration of polymorphonuclear neutrophils (PMN), which were highly activated, particularly regarding their bactericidal potential, such as increased production of superoxides and upregulation of activation-associated surface receptors.

Conclusion: PMN are activated in response to the implant-associated osteomyelitis; they also infiltrate the infected tissue, but cannot control the infection. By release of their cytotoxic entities they could contribute to tissue destruction and eventually to osteolysis.