Failure of trabecular bone with simulated lytic defects can be predicted non-invasively by structural analysis
Failure of trabecular bone with simulated lytic defects can be predicted non-invasively by structural analysis
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DOI：
10.1016/orthres.2003.09.006
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发表时间：
2004-05-01
影响因子：
2.8
通讯作者：
Snyder, BD
中科院分区：
文献类型：
--
作者：
Hong, J;Cabe, GD;Snyder, BD
对于患有转移性或良性骨骼肿瘤的患者来说，病理性骨折是一个很大的风险。治疗这些患者的医生面临的两难境地是，在做出诊断后，他们必须尝试从放射检查中看到的图像来预测受累骨骼的承载能力和骨折风险。由于骨在与密度无关的相对恒定的应变下破坏，我们用材料力学的方法证明，受溶骨性缺陷影响最大的骨的横截面结构属性决定了整个骨的承载能力。取自鲸骨脊椎的同质柱状骨芯，用不同大小的圆形或开槽的穿孔缺损物制备，以模拟溶骨性骨肿瘤。使用定量计算机断层扫描(CT)、双能X射线吸收法(DXA)和磁共振成像(MRI)对每个标本进行成像，以获得用于计算横截面结构特性的数据：轴向、弯曲和扭转刚度。根据QCT、DXA和核磁共振数据，测量的拉伸屈服载荷、弯曲和扭转屈服力矩分别与轴向、弯曲和扭转结构刚度呈显著正相关[QCT：拉伸r(2)=0.951，弯曲r(2)=0.909，扭转r(2)=0.914(p<；0.001)；DXA：拉伸r(2)=0.926，弯曲r(2)=0.841，扭转r(2)=0.916(p<；0.001)；核磁共振：拉伸r(2)=0.916；弯曲r(2)=0.856，扭转r(2)=0.852(p<；0.001)。因此，对QCT、DXA和MRI无创性测量的含有溶骨性缺损骨的横断面几何数据进行结构刚度分析，可以用来预测受累骨的承载能力和体内相对骨折的风险。(C)2003年骨科研究会。爱思唯尔有限公司出版。保留所有权利。
Pathologic fracture is a significant risk for patients afflicted with metastatic or benign skeletal tumors. The quandary for physicians who treat these patients is that after making the diagnosis they must try to predict the load bearing capacity of the involved bone and the fracture risk from images seen in radiological examinations. Since bone fails at a relatively constant strain independent of density we demonstrate that using a mechanics of materials approach that the cross-sectional structural properties of the bone most affected by the lytic defect governs the load bearing capacity of the entire bone.Homogeneous cylindrical cores of trabecular bone were harvested from the vertebral bodies of whale spines, and prepared with circular or slotted through-hole defects of varying sizes to simulate lytic skeletal tumors. Each specimen was imaged using quantitative computed tomography (CT), dual energy X-ray absorptiometry (DXA), and magnetic resonance imaging (MRI) to obtain data for calculating cross-sectional structural properties: axial, flexural, and torsional rigidity. The specimens were then divided into groups uniformly distributed with respect to defect sizes and shapes, and subjected to uniaxial tension, four-point bending or torsion until failure.A strong positive relationship was found between measured tensile yield loads, bending, and torsional yield moments vs. axial, flexural and torsional structural rigidities respectively, calculated from QCT, DXA, and MRI data [QCT: tension r(2) = 0.951, bending r(2) = 0.909, torsion r(2) = 0.914 (p < 0.001); DXA: tension r(2) = 0.926, bending r(2) = 0.841, torsion r(2) = 0.916 (p < 0.001); MRI: tension r(2) = 0.916; bending r(2) = 0.856, torsion r(2) = 0.852 (p < 0.001)].For cylindrical cores of trabecular bone with simulated lytic defects, the load bearing capacity of the entire core was directly proportional to the axial, bending, or torsional rigidity at the weakest cross-section through the core containing the defect. Therefore structural rigidity analysis of cross-sectional geometric data measured non-invasively by QCT, DXA, and MRI of bones containing lytic defects may be used to predict the load bearing capacity of the involved bone and the relative fracture risk in vivo. (C) 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.