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骨性关节炎(PTOA)的一个重要危险因素，直到最近才能被评估，这是旨在改善治疗的有意义研究的主要障碍。这项研究的目的是使用一种临床上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患者的风险，并开发和测试防止关节不协调引起的接触应力升高的方法。在不同下肢关节的回顾性研究中，DEA将被用来确定关节接触应力的阈值，高于该阈值的PTOA最有可能超过(特定目标1)。为了加深对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的了解，将开展前瞻性研究，将接触应力水平与MRI检测到的关节表面形态变化、血清和尿液生物标记物的变化、放射学变化以及患者的疼痛和功能之间的关系进行关联(目标2)。这项研究的另外两个目标将为预防IAF后接触应力升高而采取重要的临床步骤，从而改善患者的预后。新的术中技术将被开发来评估与手术中给定的候选IAF复位相关的接触应力暴露，以便在外科医生的决策中提供信息。这些新技术将基于根据与术前CT模型相关的透视图像推断的碎片姿势；接触应力估计将使用DEA计算。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验，并与常规治疗进行比较(目标3)。在一项试点临床可行性研究中，使用环形固定器治疗严重的胫骨Pilon骨折的急性关节牵张将使用DEA、MRI和生物标记物进行评估，以确定在如此高能量的IAFS中，损伤后暂时保护受损关节表面免受有害关节接触应力是否能促进关节愈合(AIM 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).