Assessement of Trabecular Bone Strength & Damage

小梁骨强度评估

• 批准号: 6773893
• 负责人: Tony M Keaveny
• 金额: $ 17.04万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-30 至 2006-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6773893
• 关键词: bioimaging /biomedical imaging; biomechanics; bone density; bone disorder; bone fracture; bone imaging /visualization /scanning; clinical research; computed axial tomography; computer simulation; computer system design /evaluation; human tissue; mathematics; model design /development; musculoskeletal disorder diagnosis; noninvasive diagnosis; skeletal stress; substantia spongiosa

DESCRIPTION (provided by applicant): The ability to non-destructively measure trabecular bone strength and microdamage would have a profound effect in bone biomechanics research. It would enable researchers to assess bone strength longitudinally in animal models, and determine the strength behavior of bone repeatedly in the same specimen for various different types of loading cases and under simulation of various types of treatment, including drug and exercise effects. It would also greatly facilitate the study of microdamage in bone since currently this is an extremely tedious process. We propose here a method to perform such non-invasive assessment of trabecular bone strength and microdamage. This method can also be used to measure the failure properties of trabecular hard tissue material, a unique indicator of trabecular quality. The basis of this technology is the "high-resolution" finite element computer modeling technique, in which the models are derived from micro-computed tomography (micro-CT) images having spatial resolutions on the order of microns. Specifically, we plan to incorporate into these models the physics of large deformations. This will enable us to simulate the correct deformation patterns that occur in individual trabeculae when loaded to failure. We have evidence that inclusion of such behavior is crucial to the ability of such models to properly capture the strength behavior of trabecular bone of any density, but particularly at low density. To validate the models, we will also develop an automated technique for the direct three-dimensional quantification of trabecular microdamage, itself a substantial technical innovation that will greatly impact research on bone microdamage. In achieving our goal, we will test two hypotheses. First, we hypothesize that the failure strains of trabecular tissue material are independent of anatomic site even though the failure strains of the whole specimen (apparent level) are not. The reason for this is the large deformation effect, which is manifested in some sites due to the low bone density. Second, we hypothesize that microdamage within trabecular bone can be predicted based on the magnitude of the strains within the trabecular tissue. This is based on the assumption that tissue level damage occurs when the site-independent tissue failure strains are exceeded. Should this be true, it will enable researchers to use these types of computer models to study both the development and biomechanical effects of microdamage in trabecular bone at a level of detail so far unthinkable. This R21 project represents an important technological foundation for improving understanding of the failure mechanisms in trabecular bone, with particular applications to aging and osteoporosis. Specifically, by addressing strength at the whole specimen and trabecular tissue levels, as well as microdamage and large deformation architectural effects, this work will provide a comprehensive and unique approach to assessment of trabecular bone strength and quality.

描述（由申请人提供）： 非破坏性测量小梁骨强度和微型塑料的能力将对骨生物力学研究产生深远的影响。它将使研究人员能够在动物模型中纵向评估骨骼强度，并确定各种不同类型的负载病例以及在各种类型的治疗中的模拟（包括药物和运动作用）中反复反复的骨骼行为。这也将极大地促进骨骼中的微塑料研究，因为目前这是一个极其乏味的过程。我们在这里提出了一种对小梁骨强度和微塑料进行这种非侵入性评估的方法。该方法还可以用来测量小梁硬组织材料的破坏特性，这是小梁质量的独特指标。该技术的基础是“高分辨率”有限元计算机建模技术，其中模型源自具有空间分辨率在微米阶的空间分辨率的微型计算机（Micro-CT）图像。具体而言，我们计划将大变形物理学纳入这些模型。这将使我们能够在加载失败时模拟单个小梁中发生的正确变形模式。我们有证据表明，这种行为的包含对于此类模型正确捕获任何密度的小梁骨的强度行为的能力至关重要，尤其是在低密度下。为了验证模型，我们还将开发一种自动化技术，用于对小梁微型塑料的直接三维量化，这本身本身就是一种实质性的技术创新，会极大地影响对骨微塑料的研究。在实现我们的目标时，我们将检验两个假设。首先，我们假设小梁组织材料的破坏菌株与解剖部位无关，即使整个样品的破坏菌株（明显水平）却不是。原因是大变形效应，由于骨密度低，在某些位点表现出来。其次，我们假设可以根据小梁组织中的菌株的幅度来预测小梁骨内的微塑料。这是基于以下假设：当超过部位的组织衰竭菌株时，组织水平损伤发生。如果这是事实，它将使研究人员能够使用这些类型的计算机模型来研究小梁骨中微型塑料的发育和生物力学效应，以迄今为止的细节水平。该R21项目是提高对小梁骨失败机制的理解的重要技术基础，并在衰老和骨质疏松症中特别适用。具体而言，通过解决整个标本和小梁组织水平的强度，以及微型塑料和较大的变形体系结构效应，这项工作将为小梁骨强度和质量评估一种全面而独特的方法。