Development and validation of embedded micro wireless strain sensor array for in vivo characterization of contact stress distribution in hip replacement

摘要 全髋关节置换术(THA)是美国应用最广泛的骨科手术之一。不幸的是， 许多后续修改往往昂贵且效果不佳。许多仿真研究表明，这些故障 由边缘载荷和不适当的部件位置或尺寸引起的过大应力引起 手术中的选择。关节处缺乏活体应力分布表征方法 界面目前阻碍了对手术因素的影响的基本了解，例如 种植体的位置和选择对全髋关节置换术结果的影响。我们的目标是开发嵌入式、微型无线 用于体内生物力学应力分布表征的应变传感器及其有效性验证 在那里面。该项目将收获我们在可嵌入微流控传感器开发方面的最新突破 对微小菌株高度敏感的细菌。这些传感器将被进一步开发成阵列并嵌入 插入UHMWPE插件，用于体内测量应力分布。嵌入的传感器阵列 将使用身体测试来校准和验证联东综合团。我们亦会研究这项计划的影响。 X射线倾角和前倾角对接触界面应力分布的影响 髋关节。基本的假设是股骨/髋臼承重表面应力分布强烈。 与定位相关，定量相关(一旦建立)可以用来指导THA 并改善其结果。我们将追求三个具体目标。目标1：开发和校准微无线 内置在UHMWPE中的应变传感器。目标2：验证传感器阵列的应变映射能力 埋入超高相对分子质量聚乙烯的身体测试和有限元建模。目标三：初步评估 在动物研究中嵌入应变传感器。这项研究的创新之处在于它将提供精确的、活体的 髋关节界面的应力分布表征方法，目前非常需要，但 不可用。这项研究的意义在于：1)建立了高密度薄膜的制备方法 灵敏、微型、生物兼容的嵌入式无线应变传感器；2)实现表面分析 不同种植体位的应力分布；3)为今后的基础研究提供了有用的工具 其他THA参数，如假体大小和韧带张力对THA的相互影响。 股骨头/UHMWPE植入界面的生物力学环境。为体内研究提供了新的工具 应力分布的表征，这个项目结合了Cobre的研究主题在虚拟 改善肌肉骨骼健康的人体试验。

SUMMARY Total hip arthroplasty (THA) is one of the most widely performed orthopedic surgeries in the US. Unfortunately, many follow-up revisions are often expensive and ineffective. Many simulation studies show that the failures are caused by edge loading and excess stresses resulting from inappropriate component positions or size selections during surgeries. The lack of an in vivo stress distribution characterization method at the joint interface currently prevents the fundamental understanding of the effect of surgery factors such as the positioning and choice of implants on the THA outcome. Our goal is to develop embedded, micro wireless strain sensors for in vivo characterization of the biomechanical stress distribution and validate their usefulness in THA. The project will harvest our recent breakthroughs in development of embeddable microfluidic sensors that are highly sensitive to micro-strains. These sensors will be further developed into arrays and embedded into the UHMWPE insert for in vivo measurement of the stress distributions. The sensor arrays embedded in UNMWPE will be calibrated and validated using cadaver testing. We will also study the effect of the radiographic inclination angles and anteversion angles on the stress distributions at the contact interface of the hip joint. The underlying hypothesis is that the femoral/acetabular bearing surface stress distribution is strongly correlated with the positioning, and the quantitative correlation (once established) can be used to guide THA and improve its outcome. We will pursue three specific aims. Aim 1: Develop and calibrate micro wireless strain sensors embedded within UHMWPE. Aim 2: Validate the strain mapping capability of the sensor array embedded UHMWPE using cadaver testing and finite element modeling. Aim 3: Preliminarily evaluate the embedded strain sensors in animal studies. This research is innovative in that it will provide a precise, in vivo stress distribution characterization method at the hip joint interface, which is currently greatly needed but unavailable. This research is significant in that we will 1) Establish the fabrication method of the highly sensitive, micro-sized, biocompatible, embedded wireless strain sensors; 2) Enable the analysis of surface stress distribution with different implant positioning; 3) Provide a useful tool for future fundamental studies on the interrelated effects of other THA parameters, such as the component sizes and ligament tension, on the biomechanical environment at femoral head/UHMWPE insert interface. Providing a new tool for in vivo characterization of the stress distribution, this project integrates with the COBRE's research theme in virtual human trial to improve musculoskeletal health.