Characterization of endotoxins on orthopaedic fixation screws, using physicochemical surface analyses.
The objective of this study was to determine if surface analysis techniques could be used to detect endotoxin on stainless steel malleolus screws. New malleolus screws were compared to ones that had been coated in purified lipopolysaccharide (LPS) or Artificial Test Soil (ATS) containing lipopolysaccharide. X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and time-of flight secondary ion mass spectrometry (TOF-SIMS) were used to assess the fixation screws surface. Organic material was visualized on the LPS and ATS-LPS inoculated screws but not on the new unsoiled screws. This was further supported by the peaks observed at masses between 40 and 100 D in TOF-SIMS spectra of the LPS and ATS-LPS inoculated screws. After deconvolution of N1s high resolution XPS spectra, the LPS inoculated screws showed amide groups whereas the ATS-LPS inoculated screws showed predominantly nitroso groups (C-NO). Our data demonstrate that surface analysis can be used to detect organic residuals present on fixation screws. The XPS data confirmed that LPS reacted predominantly with positively charged surface metallic ions (Fe and Cr), whereas proteins reacted with the surface oxide layer of fixation screws, forming C-NO groups. The application of these surface analysis techniques will be helpful in determining if the reprocessing of such items results in an accumulation of organic material that might lead to aseptic loosening, when implanted. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:240-247, 2017.
Dental Biomaterials Research Laboratory, Faculty of Health Sciences, Department of Restorative Dentistry, University of Manitoba, 780 Bannatyne Avenue, Winnipeg, Manitoba R3E 0W2, Canada.|Laboratoire d'Innovation et d'Analyse de Bioperformance, École Polytechnique de Montréal, C.P. 5079, Succursale Centre-ville, Montréal, Québec H3C 3A7, Canada.
Rodrigo
R
França
St-Boniface Hospital Research Center, 351 Tache Avenue, Winnipeg, Manitoba R2H 2A6, Canada.|Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba R3E 0l9, Canada.
Michelle
M
Alfa
St-Boniface Hospital Research Center, 351 Tache Avenue, Winnipeg, Manitoba R2H 2A6, Canada.
Nancy
N
Olson
Laboratoire d'Innovation et d'Analyse de Bioperformance, École Polytechnique de Montréal, C.P. 5079, Succursale Centre-ville, Montréal, Québec H3C 3A7, Canada.
L'Hocine
L
Yahia
Regroupement Québecois de Matériaux de Pointe and Département de Génie Physique, École Polytechnique de Montréal, C.P. 6079, Succursale Centre-ville, Montréal, Québec H3C 3A7, Canada.
Edward
E
Sacher
D001863:Bone Screws; D004731:Endotoxins / Q000032:analysis*; D004866:Equipment Contamination; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D008070:Lipopolysaccharides; D008855:Microscopy, Electron, Scanning; D056951:Photoelectron Spectroscopy; D018629:Spectrometry, Mass, Secondary Ion
D004731:Endotoxins; D008070:Lipopolysaccharides
aseptic loosening; endotoxins; sterilization reprocessing; surface analyses