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

在马业中，由关节炎引起的跛行是失去表现的主要原因。关节炎的特征是软骨的进行性变性；骨骼末端的薄组织，使正常关节无痛地运动。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，最终发展为更深的软骨病变，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随时可用。他们通常在体检后确定治疗方案，体检可能会或可能不会结合x光或超声检查非软骨关节结构。需要一种可获得的方法来识别马的早期软骨变性，以改变兽医监测马关节健康的方式。关节电成像（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，类似于其他生物电位的收集，如心电图。软骨产生的电信号源于这种高度特化的组织对负重的反应，并与软骨质量直接相关。EAG可以检测与早期关节炎相关的细微软骨变化，这种方法在活马的小型可行性研究中得到了良好的耐受。本研究项目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，以便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)研究除软骨固有特性外，非软骨变量对EAG的影响；2)开发一个预测模型来解释EAG信号并提取有关软骨固有质量的信息；3)开发一种便携式系统，用于在实验室外收集EAG。使用马尸体关节进行的实验室测试将把eeg与关节角度、软骨接触面积以及软骨刚度、成分和结构等变量联系起来。然后，建模方法将应用于这一复杂的数据集，以查明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成功地转化为兽医的实用方法，将克服技术挑战。这个提议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在追求这个领域。

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.