JBJI Journal of Bone and Joint Infection JBJI J. Bone Joint Infect. 2206-3552 Ivyspring Göttingen, Germany 10.7150/jbji.22382 Influence of Sonication on Bacterial Regrowth from Antibiotic Loaded PMMA Scaffolds - An <em>In-vitro</em> Study Clauss Martin 1 2 Laschkolnig Esther 3 4 Graf Susanne 1 4 Kühn Klaus-Dieter 3 Kantonsspital Baselland, Liestal, Interdisciplinary Unit for Orthopaedic Infections, Switzerland Kantonsspital Baselland, Liestal, Clinic for Orthopaedics and Traumatology, Switzerland Medical University of Graz, Austria Kantonsspital Baselland, Liestal, Department for Microbiology, Switzerland 17 11 2017 2 4 213 217 Copyright: © 2017 Martin Clauss et al. 2017 This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/ This article is available from https://jbji.copernicus.org/articles/2/213/2017/jbji-2-213-2017.html The full text article is available as a PDF file from https://jbji.copernicus.org/articles/2/213/2017/jbji-2-213-2017.pdf

<p class="p p-first" id="__p2">Periprosthetic joint infection (PJI) is one of the most challenging complications after joint replacement. However, when treated correctly, chances of recovery are good. The most important step in correct diagnosis and management of PJI is the detection of the causative germ. In the last years, the use of sonication in the diagnostic process has become more important. However, this diagnostic methodology has been controversially discussed when used in combination with antibiotic loaded bone cement (PMMA), which is frequently used in joint replacement surgeries. The aim of this study was thus to analyse in vitro bacterial growth in sonication fluid cultures obtained from antibiotic loaded PMMA which were contaminated with various bacterial biofilms.</p><p id="__p3">Sonication fluid obtained from antibiotic loaded PMMA (Copal G+V and Copal G+C) and plain Palacos R (control) contaminated either with <em>S. aureus</em>, <em>E. faecalis</em>, <em>S. sanguinis</em> or <em>P.acnes</em>, were analysed for bacterial re-growth in a standardised <em>in-vitro</em> setting.</p><p class="p p-last" id="__p4">In vitro bacterial growth was not interfered by released antibiotics from sonication of antibiotic loaded PMMA for <em>S. aureus</em>, <em>E. faecalis</em> and <em>S. sanguinis.</em> However, for <em>P. acnes</em> bacterial counts were affected by the released antibiotics as well as by the time delay between sonication and analysis. The <em>in-vitro</em> data suggest sonication to be an easy and sensitive diagnostic modality to detect easy-to-detect bacteria, however, results are alarming for the difficult-to-detect bacteria <em>P. acnes</em>, indicating that further attention and research is necessary to improve the detection of difficult-to-detect bacteria.</p>

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