Guillot Martin, Gravel Pierre, Gauthier Marie-Lou, Leblond Hugues, Tremblay Maurice, Rossignol Serge, Martel-Pelletier Johanne, Pelletier Jean-Pierre, de Guise Jacques A, Troncy Eric
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.
Department of Radiology, Faculty of Medicine, University of Montréal, Montréal, QC, Canada.
J Feline Med Surg. 2015 Feb;17(2):134-43. doi: 10.1177/1098612X14537261. Epub 2014 Jun 6.
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.
本初步研究的目的是开发一种视频荧光透视运动学方法，用于评估有无骨关节炎（OA）相关残疾的猫的股关节。通过视频荧光透视对两只非OA猫和四只患有股关节OA的猫进行了评估。使用定制的C形臂X射线系统，以120帧/秒的速度采集股关节的视频荧光透视图像，同时猫在跑步机上以0.4米/秒的速度自由行走。使用图形用户界面，通过以下四个步骤提取股关节随时间的角度模式：（i）图像失真校正；（ii）图像去噪和对比度增强；（iii）逐帧解剖标记识别；（iv）统计步态分析。进行了可靠性分析。患有OA的猫表现出更大的个体内步幅和步态周期变异性。三只患有OA的猫在矢状面股关节角度运动范围内呈现左右不对称（两只猫的95%置信区间无重叠，一只猫只有轻微重叠），这与它们疼痛的OA关节一致，且步态周期持续时间更长。可靠性分析显示股关节角度的绝对变化为2°-6°，表明二维视频荧光透视技术提供了可靠的数据。建议改进此方法：如果能够记录更大的视野，从而识别和跟踪每个股骨干轴而非转子标志，则变异性可能会降低。股关节的运动范围有可能成为OA相关残疾的客观标志物。
