Quantifying 3rd Body Challenge in Total Hip Arthroplasty

描述(由申请人提供)：如果存在完全关节置换中的第三身体效应，则可以消除许多与高级轴承材料(如高度交联型聚乙烯)相关的磨损率改善。虽然长期以来一直被认为是一个潜在的临床问题，但不幸的是，量化第三身体挑战的困难使其在很大程度上局限于模糊猜测的领域。因此，减少第三小体的产生和/或研究它们对种植体性能的影响的尝试一直是零星的、不同的，而且通常在临床现实主义的基础上是有问题的。基于最近的一系列研究，这些研究有助于阐明第三身体挑战、种植体表面损伤和磨损率加速之间的机制，现在提出了两个新的翻译研究方向。这些方向中的第一个是量化人工全髋关节植入手术中主要步骤的第三代身体生成倾向。这些数据应该有助于突出具体程序阶段的相对危害性，这是构思和记录有效技术改进的必要的第一步。第二个研究方向是建立一个有临床基础的框架，为实验室第三身体磨损测试制定一个可行的共识方案。为了获得广泛的接受，这样的方案将需要涉及一个可靠的、可量化的第三身体挑战，导致临床上现实的对立面损伤。而且，它需要具有在临床现实范围内重复提供磨损率加速的能力，理想情况下具有单调的、机械接地的剂量/反应关系。拟议的工作将涉及爱荷华大学、利兹大学和俄亥俄州立大学的研究小组之间的跨学科合作。在病人手术和身体准备过程中，将在不同阶段采集假体周围组织和液体标本，从这些标本中分离并定量分析第三身体碎片。第三身体引起的磨损率加速的计算模型将被扩展，以解释形态上可识别的股骨头划痕损伤，并进行直接的物理验证。将使用新的三维激光显微测量法编制具有记录的第三身体挑战的可回收股骨头上的划痕损伤登记表，为记录具有临床代表性的划痕损伤方案和严重程度范围提供客观基础。将改进实验室方案，以从聚乙烯嵌入的第三身体碎片中产生(注册一致的)股骨头划痕，然后将损坏的头部应用于标准化的实验室磨损测试。在拟议的工作结束时，我们预计已经确定了外科植入的哪些步骤在第三次身体碎片产生方面最有问题。并且，我们期望已经开发出用于第三身体磨损率加速的实验室模拟的机械基础方案，适合作为共识测试标准的概念平台。

DESCRIPTION (provided by applicant): When present, 3rd body effects in total joint replacement can obviate many of the wear rate improvements otherwise associated with advanced bearing materials such as highly cross-linked polyethylenes. While long recognized as a potential clinical concern, the difficulties of quantifying 3rd body challenge unfortunately have kept it largely confined to the domain of nebulous conjecture. Consequently, attempts to reduce the genesis of 3rd bodies and/or to study their effects on implant performance have been sporadic, heterogeneous, and often of questionable grounding in clinical realism. Building on a series of recent studies which have helped clarify the mechanisms linking 3rd body challenge, implant surface damage, and wear rate acceleration, two new directions of translational research are now proposed. The first of these directions is to quantify the 3rd body generation propensity of major intra-operative procedural steps of THA implantation surgery. Such data should be helpful to highlight the relative deleteriousness of specific procedural stages, a necessary initial step toward conceiving and documenting effective technical improvements. The second research direction is to establish a clinically-grounded framework for a practicable consensus protocol for laboratory 3rd body wear testing. To gain widespread acceptance, such a protocol will need to involve a reliably quantifiable 3rd body challenge that causes clinically realistic counterface damage. And, it will need to have the ability to reproducibly deliver wear rate accelerations in a clinically realistic range, ideally with a monotonic, mechanistically-grounded dose/response relationship. The proposed work will involve interdisciplinary collaboration among research groups at the University of Iowa, the University of Leeds, and Ohio State University. Peri-prosthetic tissue and fluid specimens will be obtained at various stages intra-operatively during patient surgeries and in cadaver preparations, from which specimens the 3rd body debris will be isolated and quantitatively analyzed. Computational models of 3rd body-induced wear rate acceleration will be extended to account for morphologically identifiable femoral head scratch damage, with direct validation physically. A registry of scratch damage on retrieval femoral heads in constructs with documented 3rd body challenge will be compiled using novel 3-dimensional laser micrometry, providing an objective basis to document clinically representative scratch damage regimens, and ranges of severity. A laboratory protocol will be refined to generate (registry-consistent) femoral head scratching from polyethylene-embedded 3rd body debris, with the damaged heads then being applied in standardized laboratory wear testing. At the conclusion of the proposed work, we expect to have identified which steps of THA surgical implantation are most problematic in terms of 3rd body debris generation. And, we expect to have developed a mechanistically-grounded protocol for laboratory simulation of 3rd body wear rate acceleration, suitable as a conceptual platform for a consensus testing standard.