Multiaxial Strength Behavior of Human Trabecular Bone

人体骨小梁的多轴强度行为

• 批准号: 7261390
• 负责人: Tony M Keaveny
• 金额: $ 31.7万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-08-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7261390
• 关键词: Address; Affect; Alendronate; Anatomic Sites; Animals; Architecture; Behavior; Biomechanics; Bone Density; Cadaver; Canis familiaris; Clinical; Complex; Condition; Data; Decompression Sickness; Depressed mood; Dual-Energy X-Ray Absorptiometry; Elements; Etiology; Failure; Femur; Finite Element Analysis; Fracture; Goals; Hip Fractures; Human; Implant; Individual; Knee; Link; Measures; Mechanics; Modeling; Monitor; Neck; Numbers; Orthopedics; Pharmacotherapy; Property; Rate; Research Personnel; Risk; Risk Factors; Role; Series; Site; Specimen; Standards of Weights and Measures; Stress; Testing; Thick; Tissues; Work; X-Ray Computed Tomography; age related; base; bone; bone quality; bone strength; bone turnover; concept; density; falls; insight; interest; osteoporosis with pathological fracture; programs; research study; substantia spongiosa; theories; tibia; treatment effect

DESCRIPTION (provided by applicant): The strength behavior of human trabecular bone is a critical component in the etiology of age-related osteoporotic fractures. Most hip fractures occur from falls, during which complex multi-directional ("multiaxial") stresses develop. A multiaxial failure criterion is necessary to determine whether or not the bone will fail under such circumstances. We have investigated so far in this project the multiaxial failure properties of high-density trabecular bone and have developed the first ever three-dimensional, complete multiaxial failure criterion. Our goal now is to extend that work to cover trabecular bone of any density. This is important for hip fractures since low density bone exists in many parts of the proximal femur. Other sites of interest include the proximal tibia, with particular relevance to loosening of total knee implants. It has also recently become clear that DXA, the clinical standard for bone strength assessment, has substantial limitations in its ability to predict fracture and monitor drug therapies. Bone turnover has come under intense scrutiny as a potential replacement for bone mass as a predictor of fracture and assessor of therapy, but the biomechanical mechanisms by which bone turnover might affect bone strength are poorly understood. Our second goal in this project is to understand the mechanisms of trabecular multiaxial failure and from this explain the biomechanical link between bone turnover and bone strength. We are proposing that bone turnover affects the remodeling space and that the resulting changes in the distribution of thickness within trabeculae - reflecting changes in resorption cavity geometry and number - should be manifested as changes in the apparent failure (yield) strain and/or density-strength relation of the trabecular bone, an effect that should be accentuated under multiaxial shear-type loading. This is because there is an interaction between the strain amplification effect associated with resorption cavities and the multiaxial shear-type loading conditions that promote excessive bending of individual trabeculae. A series of cadaver studies are planned to address our first goal, and a Series of animal studies using canine and ovine models are planned for the second goal, in which bone turnover is either elevated (by OVX) or depressed (by alendronate treatment). This project should provide substantial insight into the roles of trabecular bone strength and bone quality on osteoporotic fracture risk and treatment and other orthopedic applications.

描述（由申请人提供）：人类骨小梁的强度行为是年龄相关性骨质疏松性骨折病因学的关键组成部分。大多数髋部骨折是由跌倒引起的，跌倒期间会产生复杂的多向（“多轴”）应力。需要多轴失效标准来确定骨骼在这种情况下是否会失效。到目前为止，我们已经在该项目中研究了高密度骨小梁的多轴失效特性，并开发了第一个三维、完整的多轴失效准则。我们现在的目标是将这项工作扩展到覆盖任何密度的骨小梁。这对于髋部骨折很重要，因为股骨近端的许多部位都存在低密度骨。其他感兴趣的部位包括近端胫骨，与全膝关节植入物的松动特别相关。最近还清楚地表明，DXA（骨强度评估的临床标准）在预测骨折和监测药物治疗的能力方面存在很大的局限性。骨转换作为骨折预测指标和治疗评估指标，作为骨量的潜在替代品而受到严格审查，但骨转换可能影响骨强度的生物力学机制却知之甚少。我们在这个项目中的第二个目标是了解小梁多轴失效的机制，并由此解释骨转换和骨强度之间的生物力学联系。我们建议骨转换影响重塑空间，并且由此产生的小梁内厚度分布的变化（反映吸收腔几何形状和数量的变化）应表现为表观失效（屈服）应变和/或密度的变化-小梁骨的强度关系，在多轴剪切型载荷下应强调这种效应。这是因为与吸收腔相关的应变放大效应和促进单个小梁过度弯曲的多轴剪切型负载条件之间存在相互作用。计划进行一系列尸体研究来实现我们的第一个目标，并计划使用犬和绵羊模型进行一系列动物研究来实现第二个目标，其中骨转换要么升高（通过 OVX），要么降低（通过阿仑膦酸钠治疗）。该项目应深入了解骨小梁强度和骨质量对骨质疏松性骨折风险、治疗和其他骨科应用的作用。