Objective assessment of lameness in cattle after foot surgery

Assessment of lameness in cattle after foot surgery is important to monitor the recovery period, to improve the long-term success and the cows` welfare. This longitudinal multicenter retrospective study was carried out to evaluate the usefulness of automated tools of weight bearing and gait analysis following foot surgery to support the clinician to monitor lameness in cattle. For this purpose, the effect of involvement of different anatomical structures and the use of different surgery methods on gait parameters of post-operative recovery was assessed. The study consisted of 2 experiments and included cattle with unilateral foot pathologies located in the digital region which needed 1 (experiment 1; n = 30) or 2 (experiment 2; n = 4) surgical interventions. The surgical techniques were debridement, joint lavage, partial resection of bones, tendons or synovial structures, total resection of the sesamoid bone and digit amputation. Two accelerometers (400 Hz; kinematic outcome = stance phase duration; kinetic outcome = foot load and toe-off), a 4-scale weighing platform (difference of mean weight distribution across the limbs; Δweight) and a subjective locomotion score were used to evaluate gait parameters every 3 to 4 days after surgery. A repeated measures ANOVA was used in experiment 1 and a receiver operator characteristic analysis was used to determine the optimal cutoff values in experiment 2. Results showed that the differences across limbs for the pedogram variables of stance phases and peaks of foot load and toe-off, Δweight and the locomotion score were highest if joints or sesamoid bones were involved, suggesting that these cattle were more severely lame compared to cattle with more superficial foot pathologies. There was a significantly lower degree of lameness after surgical debridement and after digit amputation compared to partial and total resection of anatomical structures of the foot. The use of accelerometers and a 4-scale weighing platform represent promising objective tools for post-operative monitoring of lameness and can support the clinician in gait assessment to improve the long-term success of surgical interventions in the area of the foot.

牛足部手术后跛行（lameness）的评估，对于监测术后恢复进程、提升手术长期效果以及改善牛只福利均具有重要意义。本项多中心（multicenter）纵向（longitudinal）回顾性（retrospective）研究旨在评估足部手术后负重（weight bearing）与步态分析（gait analysis）自动化工具的应用价值，以辅助临床兽医监测牛只跛行。为此，本研究评估了不同解剖结构（anatomical structures）受累情况及不同手术方式对术后恢复阶段步态参数的影响。本研究包含两项实验，纳入了患有单侧（unilateral）蹄部趾区（digital region）病变且需接受1次（实验1，n=30）或2次（实验2，n=4）手术干预（surgical interventions）的牛只。本次研究采用的手术方式包括清创术（debridement）、关节冲洗术（joint lavage）、骨、肌腱或滑膜结构（synovial structures）部分切除术（partial resection）、籽骨（sesamoid bone）全切除术以及趾截除术（digit amputation）。本研究于术后每3至4天开展一次步态参数评估，所用工具包括两台400Hz加速度计（accelerometers，运动学指标（kinematic outcome）为站立相时长（stance phase duration），动力学指标（kinetic outcome）为足部负重（foot load）与趾离地（toe-off）参数）、一台四等份称重平台（4-scale weighing platform，用于计算四肢平均负重分布差值Δweight）以及主观运动评分（locomotion score）。实验1采用重复测量方差分析（repeated measures ANOVA），实验2则通过受试者工作特征曲线分析（receiver operator characteristic analysis）确定最佳截断值（optimal cutoff values）。研究结果显示，当病变累及关节或籽骨时，四肢间站立相、足部负重峰值与趾离地峰值、Δweight以及运动评分的步态图（pedogram）参数差异最为显著，提示此类牛只的跛行程度较仅患有浅表足部病变（superficial foot pathologies）的牛只更为严重。与足部解剖结构部分切除术及全切除术相比，清创术与趾截除术后的跛行程度显著更低。加速度计与四等份称重平台的联用，可为牛只术后跛行监测提供极具应用前景的客观工具，能够辅助临床兽医开展步态评估，进而提升足部外科手术干预的长期效果。