Improving the Performance of Elbow Reconstruction

描述（由申请人提供）：全肘关节置换术（TEA）不像膝关节和髋关节置换术那样可预测或持久。不幸的是，其他治疗关节炎和肘部复杂创伤的方法甚至效果更差。很少有人关注TEA失败，尽管这一问题带来了毁灭性的残疾。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，因此很难评估这些因素的相对重要性。然而，最常见的失效模式，无菌松动和过度聚乙烯磨损，表明生物力学因素占主导地位。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物性能？为了回答这个问题，我们将采用综合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负荷。接下来，我们将把这些载荷应用到植入TEA组件的肱骨和尺骨的数值模型中，以检查水泥和骨、界面和聚乙烯关节表面产生的应力，作为潜在植入物松动的措施。在进行这些分析时，我们将利用基于统计的方法及时且经济地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，我们将通过回顾性分析一系列失败的TEA病例的x线摄影观察，以及对取出的种植体部件的检索分析，来确认我们分析的机械失效模式。然后，我们可以破译哪些因素在产生载荷和界面条件中是重要的，这些因素解释了为什么在骨植入系统的特定区域发生故障。我们还将通过将分析结果与回收聚乙烯部件的磨损和变形观察结果进行比较，来解释哪些因素对轴承表面失效影响最大。我们的研究提供的信息可能反过来使我们能够更好地预测已经接受过TEA的患者即将发生的失败，建议改变手术技术和器械以改善结果，并建议TEA患者应该考虑术后活动限制。然而，考虑到当代tea的糟糕表现，我们也可能发现可以改善性能的设计变更。

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.