Research on X-ray measurements of Remodeling Stress in Living Bone Tissue

活骨组织重塑应力的X射线测量研究

基本信息

批准号：
12480254
负责人：
TADANO Shigeru
金额：
$ 6.46万
依托单位：
HOKKAIDO UVIERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12480254/
关键词：
Biomechanics Bone Structure Remodeling Cortical Bone X-ray Diffraction Residual Stress

项目摘要

Bone tissue is a composite material composed of hydroxyapatite (Hap) and collagen. Because Hap in bone tissue makes a crystal structure, an X-ray diffraction method is available to measure the strain of Hap. This study presents an X-ray diffraction method of measuring the residual stress/strain in bone tissue of rabbit's tibia . Bone powder of the diameter less than 40 micrometer was used as a control specimen at non-stressed state. From the measurements, it was clear that the distribution of residual stress existed in the bone tissue. The tensile residual stress at bone axial direction occurred in the proximal-medial region of rabbit's tibia. The compressive stress occurred in the other regions. In addition, the mechanism to generate the residual stress was investigated by sequential cutting of the tibia specimen from bone structure scale to bone tissue scale. The remodeling is a phenomenon that bone tissue and structure adapts functionally to mechanical environment. The residual stre … More ss will become a mechanical trigger to induce the remodeling.In the X-ray diffraction method using characteristic X-rays with a unique wavelength, Hap in compact bone has much lower crystallization than metal as steel. The peak position of diffracted intensity is not easy to determine form the gradual intensity-angle profile. This work proposes a method to calculate the lattice strain from the information of a whole diffraction profile without a peak position. In this experiment, strip specimens of 28x8x2 mm in size with their long axis aligned to the bone axial or the circumferential direction were cut from cortical bone in a shaft of bovine femur. To confirm the relationship between applied macroscopic strain and lattice strain in bone tissue, a four-point bending device was developed to apply bending load to the specimen during the X-ray irradiation. Macroscopic strain of the specimen was measured by a strain-gauge bonded to opposite side of the surface irradiated by X-rays. As a result, the accuracy of measurement by this method was better improved. Less

骨组织是由羟基磷灰石（Hap）和胶原蛋白组成的复合材料，由于骨组织中的Hap形成晶体结构，因此可以使用X射线衍射方法来测量Hap的应变。测量兔子胫骨骨组织中的残余应力/应变，以直径小于40微米的骨粉作为无应力状态下的对照样本。骨组织中存在残余应力分布，兔胫骨近内侧区域存在骨轴方向的残余应力，其他区域存在残余应力。通过将胫骨标本从骨结构尺度顺序切割到骨组织尺度，重塑是骨组织和结构在功能上适应机械环境的现象。残余应力将成为诱导重塑的机械触发器。使用具有独特波长的特征X射线的X射线衍射方法，致密骨中的Hap的结晶度比钢等金属低得多。这项工作不容易从渐变强度角分布中确定衍射强度的峰值位置。提出了一种根据没有峰值位置的整个衍射轮廓的信息来计算晶格应变的方法。在该实验中，尺寸为 28x8x2 mm 的条状样本，其长轴与骨轴或周向对齐。为了确认骨组织中施加的宏观应变和晶格应变之间的关系，开发了一种四点弯曲装置，在 X 射线照射期间向样本施加弯曲载荷。通过粘贴在受X射线照射的表面的另一侧的应变片来测量样品的宏观应变，结果，该方法的测量精度得到了较好的提高。