Improving the Performance of Elbow Reconstruction

描述(申请人提供)：全肘关节成形术(TEA)不如膝关节和髋关节成形术那样可预测或持久。不幸的是，其他治疗关节炎和复杂肘部创伤的方法效果更差。很少有人注意到茶衰的问题，尽管这个问题伴随着毁灭性的残疾。失败的可能原因包括生物力学、患者和手术因素。但是，由于缺乏日常活动中肘部负荷的数据，解释哪些因素最有害的努力受到阻碍，这使得评估这些因素的相对重要性变得困难。然而，最常见的失效模式，无菌性松动和过度的聚乙烯磨损，表明生物力学因素起主导作用。因此，我们建议回答以下问题：生物力学、患者和手术因素如何影响全肘关节置换术中的植入性能？为了回答这个问题，我们将用综合的方法来实现三个具体目标。首先，我们将结合TEA患者进行常见活动的运动分析和计算模型来计算关节接触载荷。接下来，我们将这些载荷应用到植入了TEA组件的肱骨和尺骨的数值模型中，以检查骨水泥和骨界面以及聚乙烯关节表面产生的应力，以此作为潜在种植体松动的衡量标准。在进行这些分析时，我们将利用基于统计的方法，以及时和经济高效的方式检查重要的环境变量(关节载荷、部件位置和方向、骨骼解剖和材料特性)。最后，我们将通过回顾一系列失败的TEA病例的放射学观察以及取出的种植部件的回收分析，从我们的分析中确认机械失败的模式。然后我们可以破译哪些因素在产生载荷和界面条件方面是重要的，这些因素和界面条件解释了为什么失败发生在骨-植入系统中的特定区域。我们还将通过将我们的分析结果与对回收的聚乙烯部件的磨损和变形的观察进行比较，解释哪些因素对轴承表面故障影响最大。反过来，我们的研究提供的信息可以让我们更好地预测已经接受TEA的患者即将发生的失败，建议手术技术和器械的改变以改善结果，并建议TEA患者应该考虑的术后活动限制。然而，考虑到当代茶的糟糕性能，我们很可能会发现设计上的改变将提高性能。 与公共卫生相关：全肘关节置换术不如膝关节和髋关节置换术那么可预测或耐用，然而肘关节成形术失败的全肘关节置换术失败通常是灾难性的，导致连枷臂严重使整个上肢瘫痪。我们的目的是解释影响肘关节置换效果的生物力学、患者和手术因素。我们的目标是解释失败的位置和机制，从而提出解决方案来提高这种治疗的有效性。

DESCRIPTION (provided by applicant): Total elbow arthroplasty (TEA) is not as predictable or durable as joint arthroplasties for the knee and hip. Unfortunately, other treatments for arthritis and complex trauma of the elbow are even less effective. Little attention has been paid to TEA failure, despite the devastating disability that accompanies the problem. Possible reasons for failure include biomechanical, patient, and surgical factors. But efforts to explain which factors are most detrimental are hampered by the lack of data on the loads across the elbow during routine daily activities, making it difficult to assess the relative importance of these factors. Nonetheless, the most prevalent failure modes, aseptic loosening and excessive polyethylene wear, suggest that biomechanical factors dominate. We propose, therefore, to answer the following question: How do biomechanical, patient, and surgical factors affect implant performance in total elbow arthroplasty? To answer this question, we will use an integrated approach to accomplish three specific aims. First, we will combine motion analysis of TEA patients performing common activities with a computational model to calculate the joint contact loads. Next, we will apply these loads to numerical models of the humerus and ulna implanted with TEA components to examine the stresses created in the cement and bone, at the interfaces, and at the polyethylene joint surfaces as measures of potential implant loosening. In performing these analyses, we will utilize statistically-based methods to examine important environmental variables (joint loads, component position and orientation, and bone anatomy and materials properties) in a timely and cost efficient manner. Finally, we will confirm the mechanical failure modes from our analyses using radiographic observations from a retrospective series of failed TEA cases together with retrieval analysis of the removed implant components. We can then decipher which factors are important in generating loads and interface conditions that explain why failures occur in particular areas within the bone-implant system. We will also explain which factors most affect bearing surface failure by comparing our analytical results with observations of wear and deformation on retrieved polyethylene components. The information provided from our study may, in turn, allow us to better predict impending failures in patients who have already undergone TEA, suggest alterations in surgical technique and instrumentation to improve outcomes, and suggest postoperative limits in activity that TEA patients should consider. As likely, however, given the poor performance of contemporary TEAs, we will also discover design alterations that will improve performance. PUBLIC HEALTH RELEVANCE: Total elbow replacement is not as predictable or durable as joint replacements for the knee and hip, yet failures of total elbow replacements failed elbow arthroplasty are usually catastrophic, resulting in a flail arm that severely disable the entire upper limb. We aim to explain biomechanical, patient, and surgical factors that affect the performance of elbow replacements. Our goal is to explain the locations and mechanisms of failure, thereby suggesting solutions to improve the efficacy of this treatment.