title: Use of infrared spectroscopy for diagnosis of traumatic arthritis in horses.
abstract: OBJECTIVE
  To evaluate use of infrared spectroscopy for diagnosis of traumatic arthritis in horses.
  
  
  METHODS
  48 horses with traumatic arthritis and 5 clinically and radiographically normal horses.
  
  
  METHODS
  Synovial fluid samples were collected from 77 joints in 48 horses with traumatic arthritis. Paired samples (affected and control joints) from 29 horses and independent samples from an affected (n = 12) or control (7) joint from 19 horses were collected for model calibration. A second set of 20 normal validation samples was collected from 5 clinically and radiographically normal horses. Fourier transform infrared spectra of synovial fluids were acquired and manipulated, and data from affected joints were compared with controls to identify spectroscopic features that differed significantly between groups. A classification model that used linear discriminant analysis was developed. Performance of the model was determined by use of the 2 validation datasets.
  
  
  RESULTS
  A classification model based on 3 infrared regions classified spectra from the calibration dataset with overall accuracy of 97% (sensitivity, 93%; specificity, 100%). The model, with cost-adjusted prior probabilities of 0.60:0.40, yielded overall accuracy of 89% (sensitivity, 83%; specificity, 100%) for the first validation sample dataset and 100% correct classification of the second set of independent normal control joints.
  
  
  CONCLUSIONS
  The infrared spectroscopic patterns of fluid from joints with traumatic arthritis differed significantly from the corresponding patterns for controls. These alterations in absorption patterns may be used via an appropriate classification algorithm to differentiate the spectra of affected joints from those of controls.
authors.affiliation: Department of Health Management, University of Prince Edward Island, PE C0A 1T0, Canada.
authors.forename: Monchanok
authors.initials: M
authors.lastname: Vijarnsorn
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Riley
authors.forename: R Anthony
authors.initials: RA
authors.lastname: Shaw
authors.forename: C Wayne
authors.initials: CW
authors.lastname: McIlwraith
authors.forename: Daniel A J
authors.initials: DA
authors.lastname: Ryan
authors.forename: Patricia L
authors.initials: PL
authors.lastname: Rose
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Spangler
mesh_terms: D000818:Animals; D001168:Arthritis / Q000175:diagnosis / Q000662:veterinary*; D005260:Female; D006734:Horse Diseases / Q000175:diagnosis*; D006736:Horses; D008297:Male; D013055:Spectrophotometry, Infrared / Q000379:methods / Q000662:veterinary*; D013582:Synovial Fluid / Q000737:chemistry; D014947:Wounds and Injuries / Q000175:diagnosis / Q000662:veterinary*