Article ID Journal Published Year Pages File Type
2780193 Bone 2011 8 Pages PDF
Abstract

There is no adequate animal model to mimic the difficult clinical situation of infected non-union of the tibia after intramedullary stabilization. The purpose was to establish an animal model of implant-related infected non-unions of the tibia in rats. Furthermore, it was evaluated if detection of bacteria by fluorescent in situ hybridisation (FISH) technique is possible in bone infection.17 rats were used in which osteotomy of the midshaft tibia was performed and stabilized with an intramedullary device. Two groups were tested: group 1: contamination of the osteotomy site with 104 colony forming units (CFUs) of Staphylococcus aureus (11 animals), group 2: no bacterial contamination (6 animals). The animals were sacrificed after 42 days and bone healing and infection were assessed clinically, by X-ray, micro-CT, and microbiological methods including FISH technique using EUB and STAPHY probes. Histology and scanning electron microscopy (SEM) for biofilm formation were performed.All animals of the control group showed uneventful bone healing after 6 weeks without any signs of local infections. 10 of 11 (90.9%) animals of group 1 with bacterial contamination exhibited infected non-union formation with positive clinical, radiological and microbiological infection signs of the tibia but without any systemic infection signs. FISH technique was able to identify bacteria in the infected bone. All intramedullary implants from the infected animals showed positive biofilm formation in SEM.This work presents the first animal model for the induction of intramedullary device-related infected non-union in the tibia and detection of bacteria by FISH technique in infected bone.

Research highlights► The model mimics infected non-unions after tibia nailing. ► Induction of infected non-union after intramedullary nailing is possible in rats. ► Detection of bacteria in bone by fluorescent in situ hybridisation is possible. ► The model is of interest for prevention, treatment and diagnosis of bone infection.

Related Topics
Life Sciences Biochemistry, Genetics and Molecular Biology Developmental Biology
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