title: The release of gentamicin from acrylic bone cements in a simulated prosthesis-related interfacial gap.
abstract: Gentamicin is added to polymethylmethacrylate bone cements in orthopedics as a measure against infection in total joint arthroplasties. Numerous studies have been published on gentamicin release from bone cements, but none have been able to estimate the local concentrations in the prosthesis-related interfacial gap, present after implantation. The aim of this study was to develop a method allowing determination of antibiotic release in such a gap. Two-hundred-micrometer-wide gaps with a volume of 6 microl and a surface area of 0.6 cm2 were created by inserting stainless-steel strips in gentamicin-loaded bone cement plugs prior to polymerization. After hardening, the gap surface was exposed to 6 microl or 10 ml of phosphate-buffered saline. Within 2 h, gentamicin concentrations in the gaps reached around 4000 microg/ml for 4 different CMW and Palamed cements and 2500 microg/ml for Palacos R. Concentrations measured in the larger volume were several hundred times lower than in the gaps. This simulated prosthesis-related interfacial gap model offers new insights in the clinical efficacy of antibiotic-loaded bone cements. It is demonstrated that concentrations up to 1000-fold the antibiotic resistance levels for most bacterial strains causing implant infection can be achieved in a realistic in vitro model.
authors.affiliation: Department of Biomedical Engineering, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands.
authors.forename: Johannes G E
authors.initials: JG
authors.lastname: Hendriks
authors.forename: Daniëlle
authors.initials: D
authors.lastname: Neut
authors.forename: Jim R
authors.initials: JR
authors.lastname: van Horn
authors.forename: Henny C
authors.initials: HC
authors.lastname: van der Mei
authors.forename: Henk J
authors.initials: HJ
authors.lastname: Busscher
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism*; D005839:Gentamicins / Q000378:metabolism*; D019904:Polymethyl Methacrylate / Q000378:metabolism*; D019736:Prostheses and Implants
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins; D019904:Polymethyl Methacrylate