title: Use of vitamin B12 in joint lavage for determination of dilution factors of canine synovial fluid.
abstract: OBJECTIVE
  To test a modified saline (0.9% NaCl) solution joint washing (lavage) technique that includes the use of vitamin B12 as an internal marker for the evaluation of synovial fluid dilution in lavage samples from canine joints.
  
  
  METHODS
  9 plasma samples obtained from blood samples of 9 healthy dogs and 9 synovial fluid samples aspirated from stifle joints of 9 cadaveric dogs.
  
  
  METHODS
  Photometric absorbances of 25% vitamin B12 solution, canine synovial fluid, and canine plasma were measured in a spectrophotometer to establish an optimal wavelength for analysis. Canine synovial fluid and plasma samples were mixed with the 25% vitamin B12 solution to obtain 1%, 3%, 5%, 10%, 20%, and 50% solutions of synovial fluid or plasma. Diluted synovial fluid and plasma samples were used to simulate joint lavage samples and to examine the possible interference of these substances (synovial fluid or plasma) with the absorbance of the 25% vitamin B12 solution in photometric analysis.
  
  
  RESULTS
  The optimal wavelength was found to be at 550 nm. Canine synovial fluid and plasma samples did not interfere with the absorbance measurements of the 25% vitamin B12 solution up to a 50% dilution of plasma or synovial fluid.
  
  
  CONCLUSIONS
  The modified saline solution joint lavage method with the use of a 25% vitamin B12 solution as an internal standard provides an accurate and reliable technique for the evaluation of synovial fluid dilution in lavage samples from canine joints.
authors.affiliation: Department of Diagnostic Imaging of Domestic Animals, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Tanya
authors.initials: T
authors.lastname: de Bruin
authors.forename: Hilde
authors.initials: H
authors.lastname: de Rooster
authors.forename: Henri
authors.initials: H
authors.lastname: van Bree
authors.forename: Eric
authors.initials: E
authors.lastname: Cox
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000097:blood / Q000378:metabolism*; D004285:Dogs; D007592:Joint Diseases / Q000097:blood / Q000378:metabolism / Q000662:veterinary*; D012016:Reference Values; D013056:Spectrophotometry, Ultraviolet; D018709:Statistics, Nonparametric; D013264:Stifle; D013582:Synovial Fluid / Q000737:chemistry*; D007507:Therapeutic Irrigation / Q000379:methods / Q000662:veterinary*; D014805:Vitamin B 12 / Q000032:analysis* / Q000378:metabolism
chemical_list: D014805:Vitamin B 12