title: Coxofemoral joint kinematics using video fluoroscopic images of treadmill-walking cats: development of a technique to assess osteoarthritis-associated disability.
abstract: The objectives of this pilot study were to develop a video fluoroscopy kinematics method for the assessment of the coxofemoral joint in cats with and without osteoarthritis (OA)-associated disability. Two non-OA cats and four cats affected by coxofemoral OA were evaluated by video fluoroscopy. Video fluoroscopic images of the coxofemoral joints were captured at 120 frames/s using a customized C-arm X-ray system while cats walked freely on a treadmill at 0.4 m/s. The angle patterns over time of the coxofemoral joints were extracted using a graphic user interface following four steps: (i) correction for image distortion; (ii) image denoising and contrast enhancement; (iii) frame-to-frame anatomical marker identification; and (iv) statistical gait analysis. Reliability analysis was performed. The cats with OA presented greater intra-subject stride and gait cycle variability. Three cats with OA presented a left-right asymmetry in the range of movement of the coxofemoral joint angle in the sagittal plane (two with no overlap of the 95% confidence interval, and one with only a slight overlap) consistent with their painful OA joint, and a longer gait cycle duration. Reliability analysis revealed an absolute variation in the coxofemoral joint angle of 2º-6º, indicating that the two-dimensional video fluoroscopy technique provided reliable data. Improvement of this method is recommended: variability would likely be reduced if a larger field of view could be recorded, allowing the identification and tracking of each femoral axis, rather than the trochanter landmarks. The range of movement of the coxofemoral joint has the potential to be an objective marker of OA-associated disability.
authors.affiliation: Québec Animal Pharmacology Research Group (GREPAQ), Department of Veterinary Biomedical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Montréal, QC, Canada Osteoarthritis Research Unit, CRCHUM, Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada.
authors.forename: Martin
authors.initials: M
authors.lastname: Guillot
authors.affiliation: Department of Radiology, Faculty of Medicine, University of Montréal, Montréal, QC, Canada.
authors.forename: Pierre
authors.initials: P
authors.lastname: Gravel
authors.affiliation: Québec Animal Pharmacology Research Group (GREPAQ), Department of Veterinary Biomedical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Montréal, QC, Canada.
authors.forename: Marie-Lou
authors.initials: ML
authors.lastname: Gauthier
authors.affiliation: Central Nervous System Research Group, Department of Physiology, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada.
authors.forename: Hugues
authors.initials: H
authors.lastname: Leblond
authors.affiliation: Central Nervous System Research Group, Department of Physiology, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada.
authors.forename: Maurice
authors.initials: M
authors.lastname: Tremblay
authors.affiliation: Central Nervous System Research Group, Department of Physiology, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada.
authors.forename: Serge
authors.initials: S
authors.lastname: Rossignol
authors.affiliation: Osteoarthritis Research Unit, CRCHUM, Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada.
authors.forename: Johanne
authors.initials: J
authors.lastname: Martel-Pelletier
authors.affiliation: Osteoarthritis Research Unit, CRCHUM, Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Pelletier
authors.affiliation: Imaging and Orthopedic Research Laboratory (LIO), Research Center of the University of Montréal Hospital Centre (CRCHUM), School of Superior Technology, Université de Québec, Québec, QC, Canada.
authors.forename: Jacques A
authors.initials: JA
authors.lastname: de Guise
authors.affiliation: Québec Animal Pharmacology Research Group (GREPAQ), Department of Veterinary Biomedical Sciences, Faculty of Veterinary Medicine, Université de Montréal, Montréal, QC, Canada Osteoarthritis Research Unit, CRCHUM, Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada eric.troncy@umontreal.ca.
authors.forename: Eric
authors.initials: E
authors.lastname: Troncy
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002371:Cat Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D002415:Cats; D005471:Fluoroscopy / Q000662:veterinary; D005684:Gait / Q000502:physiology*; D006621:Hip Joint; D007700:Kinetics; D010003:Osteoarthritis / Q000000981:diagnostic imaging / Q000662:veterinary*; D010865:Pilot Projects; D015203:Reproducibility of Results; D014741:Video Recording / Q000379:methods*; D016138:Walking