title: Comparison of the elution properties of commercially available gentamicin and bone cement containing vancomycin with 'home-made' preparations.
abstract: OBJECTIVE
  Vancomycin is commonly added to acrylic bone cement during revision arthroplasty surgery. Proprietary cement preparations containing vancomycin are available, but are significantly more expensive. We investigated whether the elution of antibiotic from 'home-made' cement containing vancomycin was comparable with more expensive commercially available vancomycin impregnated cement.
  
  
  METHODS
  A total of 18 cement discs containing either proprietary CopalG+V; or 'home-made' CopalR+G with vancomycin added by hand, were made. Each disc contained the same amount of antibiotic (0.5 g gentamycin, 2 g vancomycin) and was immersed in ammonium acetate buffer in a sealed container. Fluid from each container was sampled at eight time points over a two-week period. The concentrations of gentamicin and vancomycin in the fluid were analysed using high performance liquid chromatography mass spectrometry.
  
  
  RESULTS
  The highest peak concentrations of antibiotic were observed from the 'home-made' cements containing vancomycin, added as in the operating theatre. The overall elution of antibiotic was, fivefold (vancomycin) and twofold (gentamicin) greater from the 'home-made' mix compared with the commercially mixed cement. The use of a vacuum during mixing had no significant effect on antibiotic elution in any of the samples.
  
  
  CONCLUSIONS
  These findings suggest that the addition of 2 g vancomycin powder to gentamicin-impregnated bone cement by hand significantly increases the elution of both antibiotics compared with commercially prepared cements containing vancomycin. We found no significant advantages of using expensive commercially produced vancomycin-impregnated cement and recommend the addition of vancomycin powder by hand in the operating theatre. Cite this article: Bone Joint J 2017;99-B:73-7.
authors.affiliation: Sheffield Teaching Hospitals NHS Foundation Trust, Herries Road, Sheffield, S5 7AU, UK.
authors.forename: N M
authors.initials: NM
authors.lastname: Frew
authors.affiliation: Sheffield Teaching Hospitals NHS Foundation Trust, Herries Road, Sheffield, S5 7AU, UK.
authors.forename: T
authors.initials: T
authors.lastname: Cannon
authors.affiliation: Sheffield Hallam University, City Campus, Howard Street, Sheffield, S1 1WB, UK.
authors.forename: T
authors.initials: T
authors.lastname: Nichol
authors.affiliation: Sheffield Hallam University, City Campus, Howard Street, Sheffield, S1 1WB, UK.
authors.forename: T J
authors.initials: TJ
authors.lastname: Smith
authors.affiliation: Sheffield Teaching Hospitals NHS Foundation Trust, Herries Road, Sheffield, S5 7AU, UK.
authors.forename: I
authors.initials: I
authors.lastname: Stockley
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry*; D019643:Arthroplasty, Replacement / Q000379:methods; D001843:Bone Cements / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D004338:Drug Combinations; D005839:Gentamicins / Q000737:chemistry*; D013058:Mass Spectrometry; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D014618:Vacuum; D014640:Vancomycin / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D001843:Bone Cements; D004338:Drug Combinations; D005839:Gentamicins; D014640:Vancomycin; D019904:Polymethyl Methacrylate
keywords: Antibiotic elution; Antibiotic impregnated bone cement; Periprosthetic joint infection; Revision arthroplasty; Vancomycin