Corrosion Induced Hip Implant Failure: Synergistic Interactions of Patient, Mater

全髋关节置换术(THR)患者的局部不良反应(ALTRs)呈上升趋势 与假体周围感染并列为THR失败的主要原因。产生的腐蚀产物 植入物的模块结会导致ALTR；因此，模块结腐蚀是最紧迫的问题之一 关节成形术的主题。这项工作的长期目标是减少腐蚀损害并增加 通过优化材料质量和表面光洁度来延长THR的寿命。此应用程序的目标是 确定导致高位移位的腐蚀模式以及它们如何依赖于材料、植入物设计、手术 植入物和患者因素。中心假设是，特定的腐蚀模式可以被一种 均匀的种植体合金，晶粒度适中，整体和局部种植体具有最佳的协同作用 设计因素。这项拟议研究的基本原理是，确定材料的微观结构 最大限度地减少腐蚀和微运动的表面形貌将改善模块连接并减少 植入失败。我们有三个具体的目标：1)确定材料，植入设计，外科植入和 使用a)恢复分析最显著地减少模块连接中的腐蚀损害的患者因素 以及b)多尺度有限元分析(FEA)；2)确定合金的微观组织如何影响特定的 A)循环载荷和b)附加微动(微动)下的腐蚀模式，以及实验和 陶瓷封头干预对陶瓷材料腐蚀和力学行为影响的数值模拟 这些合金；以及3)确定特定的腐蚀模式和随后的腐蚀产物如何影响 ALTRs的发生、范围和类型(以巨噬细胞或淋巴细胞为主)。在目标1下，我们将 量化回收的THR上的腐蚀损伤程度，并使用以前开发的多尺度有限元分析来 确定可将腐蚀损害降至最低的材料、植入物设计和外科植入物因素 病人之间的差异。在目标2下，从回收的植入物中制备的材料样本将用于 缝隙腐蚀和微动腐蚀试验，以确定材料微观结构对金属离子释放的影响。 实验测试和有限元分析将被用来调查陶瓷外科干预的后果。 损坏的杆锥上的股骨头。在AIM 3下，来自患者的组织样本和种植表面 巨噬细胞和淋巴细胞主导的ALTRs将被分析，并与功能正常的ALTRs进行比较 (尸检)对照。实验方法是创新的，因为它使用了实际的植入材料 采样，施加更多只能通过多尺度有限元分析得出的相关载荷和运动，并分析 使用从相同取回的种植体中提取的组织样本的腐蚀模式的生物影响。建议数 这项研究意义重大，因为它将共同填补关于模块连接中腐蚀的知识空白 通向ALTR。归根结底，这些知识有可能推动新的制造、质量控制和 THR的临床前测试方法，延长植入物的寿命，改善THR患者的福祉。

Adverse local tissue reactions (ALTRs) in patients with total hip replacements (THRs) are on the rise and are on par with periprosthetic infection as a major reason for THR failure. Corrosion products generated within modular junctions of the implants lead to ALTRs; thus, modular junction corrosion is one of the most urgent topics in joint arthroplasty. The long term goal of this work is to reduce corrosion damage and increase longevity of THRs by optimizing material quality and surface finish. It is the objective of this application to identify modes of corrosion that lead to ALTRs and how they depend on material, implant design, surgical implantation and patient factors. The central hypothesis is that specific corrosion modes can be inhibited by a homogeneous implant alloy with moderate grain size and optimal synergism between global and local implant design factors. The rationale underlying the proposed research is that, determining the material microstructure and surface topography that minimizes corrosion and micromotion will improve modular junctions and reduce implant failure. We have three specific aims: 1) Identify the material, implant design, surgical implantation and patient factors that most significantly reduce corrosion damage in modular junctions using a) retrieval analysis and b) multiscale finite element analysis (FEA); 2) Determine how alloy microstructure affects specific corrosion modes under a) cyclic load, and b) additional micromotion (fretting), and experimentally and computationally simulate the effect of ceramic head intervention on the corrosion and mechanical behavior of these alloys; and 3) Determine how specific modes of corrosion and subsequent corrosion products influence the occurrence, extent and type of ALTRs (macrophage or lymphocyte dominated). Under aim 1, we will quantify the extent of corrosion damage on retrieved THRs, and use previously developed multiscale FEA to determine the material, implant design and surgical implantation factors that minimize corrosion damage, given differences in the patient. Under aim 2, material samples prepared from the retrieved implants will be used in crevice- and fretting-corrosion tests to determine the effect of material microstructure on metal ion release. Experimental tests and FEA will be used to investigate the consequences of surgical intervention with ceramic femoral heads on damaged stem tapers. Under aim 3, tissue samples and implant surfaces from patients with macrophage and lymphocyte dominated ALTRs will be analyzed and compared to well-functioning (postmortem) controls. The experimental approach is innovative because it uses actual implant material samples, applies more relevant loads and motions which can only be derived by multiscale FEA, and analyzes the biological impact of corrosion modes using tissue samples from the same retrieved implants. The proposed research is significant because it will collectively fill a knowledge gap on how corrosion in modular junctions leads to ALTRs. Ultimately this knowledge has the potential to drive new manufacturing, quality control and preclinical testing methods for THRs, increasing implant life time and improving the well-being of THR patients.