title: Changes in the Chemical Quality of Bone Grafts During Clinical Preparation Detected by Raman Spectroscopy.
abstract: METHODS
  We determined the content of amide I, amide III, PO4, CO3, and CH2 in samples of fresh bone, bone frozen at -80°C thawed once, bone after two freeze-thaw cycles, and chemically cleaned bone chips. A total of 750 Raman spectra were collected per sample group and the derived quantitative values compared statistically by one-way ANOVA.
  
  
  RESULTS
  We found statistically significant differences between the investigated sample groups differing in their treatment already after one freeze-thaw cycle and as well after multiple freeze-thaw cycles, and/or chemical cleaning. Chemical cleaning decreased the content of all measured components compared to the fresh sample as detected by Raman spectroscopy. We further used the derived data to calculate the mineral to matrix ratios for each sample group.
  
  
  CONCLUSIONS
  Our data indicate that significant changes of the chemical quality and mineral to matrix ratio occur during freeze-thawing and chemical cleaning. At the same time, this study highlights the importance of sampling and testing at multiple locations for reliable predictions of the chemical composition. We think that it is very desirable to test the quality of bone graft material before transfer to a recipient; this might ultimately help define parameters to choose the best graft for the patient. It is also important to highlight that this is a preliminary study, which shows the importance of detecting changes in the chemical quality of bone grafts before transfer to the patient.
authors.affiliation: 1 Experimental Orthopedics, Medical University of Innsbruck , Innsbruck, Austria .|2 University Hospital for Orthopedics, Medical University of Innsbruck , Innsbruck, Austria .
authors.forename: Alexander
authors.initials: A
authors.lastname: Wurm
authors.affiliation: 3 Department of Neuroradiology, Medical University of Innsbruck , Innsbruck, Austria .
authors.forename: Ruth
authors.initials: R
authors.lastname: Steiger
authors.affiliation: 1 Experimental Orthopedics, Medical University of Innsbruck , Innsbruck, Austria .
authors.forename: Christoph G
authors.initials: CG
authors.lastname: Ammann
authors.affiliation: 1 Experimental Orthopedics, Medical University of Innsbruck , Innsbruck, Austria .
authors.forename: David
authors.initials: D
authors.lastname: Putzer
authors.affiliation: 2 University Hospital for Orthopedics, Medical University of Innsbruck , Innsbruck, Austria .
authors.forename: Michael C
authors.initials: MC
authors.lastname: Liebensteiner
authors.affiliation: 1 Experimental Orthopedics, Medical University of Innsbruck , Innsbruck, Austria .|2 University Hospital for Orthopedics, Medical University of Innsbruck , Innsbruck, Austria .
authors.forename: Michael
authors.initials: M
authors.lastname: Nogler
authors.affiliation: 1 Experimental Orthopedics, Medical University of Innsbruck , Innsbruck, Austria .
authors.forename: Débora C
authors.initials: DC
authors.lastname: Coraça-Huber
mesh_terms: D000577:Amides / Q000737:chemistry; D016025:Bone Transplantation; D002254:Carbonates / Q000737:chemistry; D015925:Cryopreservation / Q000379:methods*; D005030:Ethylenes / Q000737:chemistry; D005260:Female; D006801:Humans; D010710:Phosphates / Q000737:chemistry; D013059:Spectrum Analysis, Raman; D019737:Transplants / Q000737:chemistry* / Q000592:standards*
chemical_list: D000577:Amides; D002254:Carbonates; D005030:Ethylenes; D010710:Phosphates; C036216:ethylene