BONE AND KNEE LOADING

描述（由申请人提供）：老年人的主要健康需求之一是强化骨骼和预防骨量。在这个项目中，我们提出了一种新的机械加载模型-膝关节加载-刺激骨形成和加强股骨和股骨颈的力学性能。在我们使用小鼠尺骨的初步研究中，通过加载肘关节来刺激骨形成。此外，该肘加载模型诱导骨形成所需的载荷小于传统的纵向尺骨加载模型。这些结果表明，股骨和股骨颈可以通过施加到膝关节的机械负荷来加强。该项目的具体目标是评估施加在膝关节上的载荷对股骨和股骨颈的骨量和机械强度的影响。在拟议的研究中测试的假设是：“膝关节上-20 Hz下< 1 N的低振幅正弦机械载荷将刺激股骨和股骨颈中的新骨形成，并增加对骨折的抵抗力。“在建议的研究中，我们首先会研究水流势能和耗散能，以确定合适的膝部负荷情况。将生理频率的机械载荷施加到膝关节，并确定股骨中的流动电位和耗散能量。使用诱导流动电位和提高耗散能的条件，然后我们将通过骨组织形态计量学、显微计算机断层扫描（mu CT）和生物力学测试来评估载荷效应。C57 BL/6小鼠将被给予机械负荷，每天3分钟，连续3天。用钙黄绿素对新形成的骨进行染色后，将沿股骨中段沿着测定骨形态测量参数。将使用mu CT确定三维形态，并确定力学参数，如极限力和失效功。这项研究将有助于开发一种新的加载模型，以加强骨，而不会导致老年人脆弱的骨变形。

DESCRIPTION (provided by applicant): One of the major health needs in the elderly is to strengthen bone and prevent bone mass. In this project, we propose to investigate a novel mechanical loading model- knee joint loading - to stimulate bone formation and to strengthen mechanical properties of femur and a femoral neck. In our preliminary studies using mouse ulnae, bone formation was stimulated by loading an elbow joint. Furthermore, the loads required to induce bone formation with this elbow-loading model were smaller than that with a traditional longitudinal ulna-loading model. These results suggest that femur and a femoral neck can be strengthened by mechanical loads that are applied to a knee joint. The specific goal of the proposed project is to evaluate the effects of loads applied to the knee joint on bone mass and mechanical strength of femur and a femoral neck. The hypothesis, tested in the proposed study, is: "Low-amplitude sinusoidal mechanical loads with < 1 N at -20 Hz on a knee joint will stimulate new bone formation in femur and a femoral neck, and increase resistance to fracture." In the proposed study we will first identify the appropriate knee-loading conditions by examining streaming potentials and dissipation energy. Mechanical loads at physiological frequencies will be applied to the knee joint and streaming potentials and dissipation energy will be determined in the femur. Using the conditions that induce streaming potentials and elevate dissipation energy, we will then evaluate the loading effects through bone histomorphometry, micro-Computed Tomography (mu CT), and biomechanical tests. C57BL/6 mice will be given mechanical loads for 3 min per day for 3 consecutive days. After staining newly formed bone with calcein, bone morphometric parameters will be determined along a femoral midshaft. Three-dimensional morphology will be determined with mu CT, and mechanical parameters such as ultimate force, and work to failure will be determined. The proposed study will contribute to development of a novel loading model to strengthen bone without causing deformation of fragile bone in the elderly.