Electroarthrography: Non-invasive evaluation of cartilage health in equine articular joints

在马产业中，关节炎导致的跛行是性能损失的主要原因。关节炎的特征是软骨的进行性退化;软骨是骨骼末端的薄组织，可以使正常的关节无痛地运动。例如，关节炎软骨可能在疾病过程的早期表现出粗糙的表面或厚度变化，其最终进展到更深的软骨病变并可能涉及其他组织。关节炎的晚期会引起疼痛和虚弱，治疗仅限于缓解症状。早期关节炎可能不会产生症状，但这正是旨在减缓疾病进展的治疗可能有效的时候。不幸的是，马兽医没有一个客观的方法来评估关节健康现成可用。他们通常在体检后确定治疗计划，体检可能会或可能不会与X射线或超声波结合，以探索非软骨关节结构。需要一种识别马早期软骨退化的方法来改变兽医监测马关节健康的方式。关节电描记术（EAG）是一种通过放置在关节周围皮肤上的电极非侵入性地测量软骨产生的电信号的方法，类似于收集其他生物电位，如心电图。由软骨产生的电信号来自于这种高度专门化的组织对承重的反应方式，并直接与软骨质量相关。EAG可以检测与早期关节炎相关的细微软骨变化，并且这种方法在活体马的小型可行性研究中耐受良好。 这项研究计划的总体目标是创建一种诊断EAG方法，可用于马兽医常规评估软骨质量，以确定旨在限制关节炎进展的早期干预机会。为了实现这一目标，具体的短期目标是：1）调查非软骨变量的影响，除了固有的软骨特性，有助于EAG，2）开发一个预测模型来解释EAG信号和提取信息的内在软骨质量，和3）开发一个便携式系统，用于收集EAG的实验室外。将使用尸体马关节进行实验室测试，以将EAG与关节角度和软骨接触面积等变量以及软骨硬度，组成和结构联系起来。然后将建模方法应用于这个复杂的数据集，以确定EAG和软骨质量之间的关系。通过简化电极应用和创建用户友好的界面，将EAG成功转化为兽医的实用方法，将克服技术挑战。该提案描述了一个令人兴奋的研究领域，目前世界上没有任何其他团体正在进行。

In the equine industry, lameness resulting from arthritis is a major cause of lost performance. Arthritis is characterized by a progressive degeneration of cartilage; the thin tissue lining the ends of bones that allows normal joints to move painlessly. Arthritic cartilage may, for example, exhibit a roughened surface or thickness changes early in the disease process, which eventually progresses to deeper cartilage lesions and may involve other tissues. Later stages of arthritis cause pain and debilitation, and treatment is limited to symptom relief. Early arthritis may not produce symptoms, yet this is precisely when treatment aimed at slowing disease progression could be effective. Unfortunately, equine veterinarians do not have an objective method for evaluating joint health readily available. They often determine treatment plans after a physical exam that may or may not be combined with X-ray or ultrasound to explore non-cartilage joint structures. An accessible method for identifying early cartilage degeneration in horses is needed to transform the way in which veterinarians monitor equine joint health. Electroarthrography (EAG) is a method by which electrical signals produced by cartilage are measured non-invasively through electrodes placed on skin surrounding an articular joint, analogous to the collection of other bio-potentials such as electrocardiography. The electrical signals produced by cartilage result from the way this highly specialized tissue responds to weight bearing and are directly linked to cartilage quality. EAG can detect subtle cartilage changes associated with early arthritis and this approach was well-tolerated in a small feasibility study in live horses. The overall goal of this research program is to create a diagnostic EAG method that can be used by equine veterinarians to routinely evaluate cartilage quality in order to identify opportunities for early intervention aimed at limiting arthritis progression. To achieve this goal, specific short term objectives are to 1) investigate the influence of non-cartilage variables in addition to intrinsic cartilage properties that contribute to EAG, 2) develop a predictive model to interpret EAG signals and extract information about intrinsic cartilage quality, and 3) develop a portable system for collecting EAG outside of the laboratory. Laboratory tests using cadaveric equine joints will be conducted to relate EAG to variables like joint angle and cartilage contact area, as well as to cartilage stiffness, composition and structure. Modelling approaches will then be applied to this complex data set to pinpoint relationships between EAG and cartilage quality. Technological challenges will be overcome through simplifying electrode application and creating a user-friendly interface to successfully translate EAG into a practical method for veterinarians. This proposal describes an exciting area of research that is not currently being pursued by any other group in the world.