MRSA infection in a large animal model: direct re-nailing with local antibiotics in a hydrogel (MRSingle)

Completed

AO Trauma

W Boot, S. Zeiter, D Eglin, F Moriarty

Background

Both one and two stage revision of fracture related infection (FRI) have a high reinfection rate, especially for infections caused by bacteria resistant to antibiotics. We have previously shown that a vancomycin and gentamicin-containing hydrogel (THH) was shown to treat MRSA-infected sheep in a two-stage exchange of an IM nail.

 

media-149220
Left: schematic image of THH (blue) applied around an IM nail in the sheep model. Right: quantitative bacteriological evaluation showing successful clearance of the infection from the IM canal and from the implant

 

Goal

The goal of this study was to determine if the locally applied antibiotic may be effective in a one-stage procedure when compared with current gold standard, antibiotic loaded bone cement.

 

Results

All sheep that completed treatment were cured of deep implant related osteomyelitis as demonstrated in the figure below. Two sheep receiving the THH and one sheep receiving PMMA had low levels of MRSA isolated in the soft tissue and/or bone at the inoculation site, indicative of superficial infection. 

Foster AL, Boot W, Stenger V, D'Este M, Jaiprakash A, Eglin D, Zeiter S, Richards RG, Moriarty TF. Single-stage revision of MRSA orthopedic device-related infection in sheep with an antibiotic-loaded hydrogel. J Orthop Res. 2020;epub Dec 11. https://doi.org/10.1002/jor.24949

Richards RG, Moriarty TF, D'Este M. Novel antimicrobial approaches to prevent orthopedic device related infection. 2021 EORS (oral)