Local Biomechanics of Median Nerve Insult in Carpal Tunnel Syndrome

描述（由申请人提供）：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一种。一般来说，对正中神经的机械损伤被公认为直接原因。然而，尽管许多学科领域已有大量研究，但对直接导致该疾病的局部生物力学损伤的客观表征仍然明显缺乏。所提出研究的中心范式是可以有意义地量化正中神经上的局部机械应力。这种机械应力是由于隧道范围内的流体压力以及正中神经与相邻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) 分析进行量化，使用基于解剖学的三维流体浸没多体接触公式，该公式已在前期工作中开发出来。该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，并用它来探索流体压力与固体接触对正常受试者和 CTS 患者正中神经应力的相对重要性。 (2)基于临床测量，系统研究个体解剖和功能参数对正中神经应力的影响，并进行逻辑回归分析，以确定最重要的影响因素或因素组。 (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 确定的最容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.