Local Biomechanics of Median Nerve Insult in Carpal Tunnel Syndrome

描述(申请人提供)：腕管综合征(CTS)是由慢性周围神经压迫引起的肌肉骨骼疾病家族中最重要的疾病之一。一般说来，机械损伤正中神经是公认的直接原因。然而，尽管在许多学科领域都有大量的研究，但直接导致这种疾病的局部生物力学损伤的客观特征仍然明显缺乏。这项研究的中心范式是，正中神经上的局部机械应力可以有意义地量化。这种机械应力是由于隧道内的流体压力以及正中神经与邻近解剖结构的直接物理接触造成的。这两种类型的相互作用都可以通过有限元(FE)分析来量化，该分析使用基于解剖学的三维流体浸泡多体接触公式，该公式已在初步工作中开发。这项研究的长期目标是建立一个客观的机制框架，将CTS与可量化的生物力学影响因素联系起来。将采用跨学科的方法，整合研究团队成员在生物力学应力分析、手外科和肌肉骨骼磁共振成像(MRI)领域的专业知识。该项目有三个具体目标：(1)完善和物理验证数值模型，并利用它来探索流体压力和固体接触对正常人和CTS患者正中神经应力的相对重要性。(2)在临床测量的基础上，系统研究个体解剖和功能参数对正中神经应力的影响，并进行Logistic回归分析，找出最重要的影响因素(S)或因素组(S)。(3)在受影响的患者组和匹配的正常受试者的阴性对照组中，测试FE确定的最易导致正中神经机械应力升高的因素与CTS症状的存在和严重程度之间的关联。

DESCRIPTION (provided by applicant): Carpal tunnel syndrome (CTS) is among the most important of the family of musculoskeletal disorders caused by chronic peripheral nerve compression. Generically, mechanical insult to the median nerve is well recognized as the proximate cause. However, despite the existing large body of research in many disciplinary areas, objective characterization of the local biomechanical insult directly responsible for the disorder remains conspicuously absent. The central paradigm of the proposed research is that local mechanical stress on the median nerve can be meaningfully quantified. This mechanical stress is due to fluid pressure within the confines of the tunnel, and direct physical contact of the median nerve with adjacent anatomic structures. Both of these types of interactions can be quantified - in tandem - by finite element (FE) analysis, using an anatomically based, three-dimensional, fluid immersion multi-body contact formulation, which has been developed in preliminary work. The long-term goal of the study is to establish an objective mechanistic framework for linking CTS with quantifiable biomechanical influence factors. An interdisciplinary approach will be adopted, integrating research team member expertise in the areas of biomechanical stress analysis, hand surgery, and musculoskeletal magnetic resonance imaging (MRI). The project has three specific aims: (1) Refine and physically validate the numerical model, and use it to explore the relative importance of fluid pressure versus solid contact on median nerve stress in normal subjects and CTS patients. (2) Based on clinical measurement, systematically study the effects of individual anatomic and functional parameters on median nerve stresses, and perform logistic regression analysis to identify the most important influence factor(s) or group(s) of factors. (3) Test for association between FE-identified factors most predisposing to elevated median nerve mechanical stress, and the presence and severity of CTS symptoms, in an affected patient group and in a negative control group of matched normal subjects.