Biomechanical behaviour of the spinal cord

本研究的主要假设是脊髓损伤的机制对损伤的类型至关重要，因此是临床决策中应考虑的重要因素。我们在过去几年的主要进展突出了几个生物力学问题，我们将在当前的建议中进行探讨。我们的具体目标是：i）记录在临床相关条件下发生的脊髓变形模式，ii）使用有限元方法模拟这些变形模式下的脊髓损伤模式。为了解决第一个具体目标，将在我们的新型实验模型中以高速率加载（~ 1 m/s）产生临床相关损伤。我们将讨论挫伤、骨折脱位和屈曲分离损伤。在撞击过程中，脊柱和脊髓的变形模式将使用我们定制设计的高速X射线系统进行监测，该系统能够以每秒1,000帧的速度进行记录。为了解决我们的第二个目标，从实验研究的动态脊髓变形将输入到我们的脊髓模型和脊髓组织的原发性损伤的程度将被预测。与第二个目标所涉及的主要任务将是完善我们目前的三椎骨颈椎有限元模型。我们会进行敏感性研究，以指导我们的发展。我们目前的策略是将脐带结构建模为散装材料，但问题的复杂性可能会迫使我们在未来开发一种更精确的脐带解剖学显微结构模型。我们预测脊髓组织损伤模式的准确性将指导这项研究。预计该研究的主要应用领域将是临床治疗的急性阶段，特别是手术干预的技术和时机以及修复/再生策略在这种急性环境中的应用。这项研究的最终成功将在未来的临床翻译中实现，这些新方法将证明脊髓损伤个体的结果得到改善。

The overriding hypothesis of this research is that the mechanism of spinal cord injury is critical to the type of damage produced and thus is an important factor that should be incorporated in clinical decision-making.Our major progress over the past several years has highlighted several biomechanical issues that we will explore in the current proposal. Our specific objectives are i) to document the cord deformation patterns that occur in clinically relevant conditions and ii) to simulate patterns of spinal cord damage under these deformation patterns using the finite element method. To address the first specific objective, clinically relevant injuries of will be produced in our novel experimental model at high rates of loading (~1m/s). We will address contusion, fracture-dislocation, and flexion-distraction injuries. During the impact event, the deformation patterns of the spinal column and spinal cord will be monitored using our custom designed high-speed Xray system, which is capable of recording at 1,000 frames per second. To address our second objective, the dynamic cord deformations from the experimental studies will be input to our spinal cord model and the degree of primary damage to the cord tissue will be predicted. The main task involved with the second objective will be to refine our current three-vertebra cervical spine finite element model. Sensitivity studies will be conducted to guide us in this development. Our current strategy is to model the cord structure as a bulk material but the complexity of the problem may force us, in the future, to develop a more anatomically accurate microstructural model of the cord. The accuracy with which we can predict tissue damage patterns in the cord will guide thisresearch. It is anticipated that the main application area for the research will be in the acute stages of clinical treatment, particularly in the technique and timing of surgical intervention as well as the application of  repair/regeneration strategies in this acute setting. Ultimate success of the research will be realized in future clinical translation of the novel methods that demonstrates enhanced outcome for spinal cord injured individuals.