Diagnosing the Treating Elevated Joint Contact Stress to Avert Post-Traumatic OA

关节内骨折（IAF）后残余关节不协调引起的关节接触应力升高是创伤后OA（PTOA）的一个至关重要的风险因素，直到最近才能评估，这对旨在改善治疗的有意义的研究构成了主要障碍。拟议研究的目标是采用一种临床适用的接触应力测量方法，通过计算离散元分析（DEA）方法获得，以诊断IAF后PTOA风险患者，并开发和测试防止关节不协调接触应力升高的方法。在不同下肢关节的回顾性研究中，将利用DEA确定关节接触应力阈值，高于该阈值时PTOA最有可能发生（具体目标1）。为了进一步了解IAF后累积接触应力升高如何影响关节结构和生物学从而导致PTOA，将进行前瞻性研究，以将接触应力水平与MRI上检测到的关节面形态学变化、血清和尿液生物标志物变化、影像学变化以及患者疼痛和功能相关（目标2）。本研究的其他两个目的将采取重要的临床步骤，以防止IAF后接触应力升高，从而改善患者结局。将开发新的术中技术，以评估手术期间与给定候选IAF减少相关的接触应力暴露，从而为外科医生的决策提供信息。这些新技术将基于从与术前CT模型相关的荧光透视图像中推断出的碎片姿态;将使用DEA计算接触应力估计值。这些技术将在模拟骨折模型上进行评估，并在IAF手术期间在手术室进行试点，并与传统治疗进行比较（目标3）。在一项初步临床可行性研究中，将使用DEA、MRI和生物标志物评估使用环形固定器治疗严重胫骨pilon骨折的急性关节牵引，以确定损伤后暂时避免受损关节面受到有害关节接触应力是否可改善此类高能量IAF的关节愈合（目标4）。

Elevated joint contact stress from residual articular incongruity following intra-articular fracture (IAF) is a critically important risk factor for post-traumatic OA (PTOA) that until recently could not be assessed, presenting a major obstacle to meaningful research aimed at improving treatment. The goals of the proposed research are to employ a clinically applicable measure of contact stress, obtained using computational discrete element analysis (DEA) methods, to diagnose patients at risk of PTOA following IAF and to develop and test methods of preventing elevated contact stress from joint incongruity. In retrospective studies of different lower extremity joints, DEA will be utilized to identify thresholds of joint contact stress above which PTOA is most highly likely (Specific Aim 1). To advance understanding of how elevated cumulative contact stress after IAF affects joint structure and biology to cause PTOA, prospective studies will be undertaken to correlate contact stress levels with morphologic articular surface changes detected on MRI, with alterations in serum and urine biomarkers, with radiographic changes, and with patient pain and function (Aim 2). The other two aims of this study will make important clinical steps to prevent elevated contact stress following IAF and thereby improve patient outcomes. New intra-operative techniques will be developed to assess the contact stress exposure associated with a given candidate IAF reduction during operations, to inform surgeons in their decision-making. These novel techniques will be based on deduced fragment poses from fluoroscopic images correlated with pre-operative CT models; contact stress estimates will be calculated with DEA. These techniques will be assessed on simulated fracture models and piloted in the operating room during IAF surgery and compared with conventional treatment (Aim 3). In a pilot clinical feasibility study, acute joint distraction using a ring fixator for severe tibial pilon fractures will be assessed using DEA, MRI and biomarkers to determine if temporarily sparing damaged articular surfaces from harmful joint contact stress after injury improves joint healing in such high energy IAFs (Aim 4).