Apparent viscoelastic anisotropy as measured from nondestructive oscillatory tests can reflect the presence of a flaw in cortical bone.
Apparent viscoelastic anisotropy as measured from nondestructive oscillatory tests can reflect the presence of a flaw in cortical bone.
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通过无损振荡测试测量的表观粘弹性各向异性可以反映皮质骨中是否存在缺陷。
DOI：
10.1002/jbm.a.20128
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Fyhrie,DavidP
中科院分区：
文献类型：
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作者：
Yeni,YenerN;Christopherson,GregoryT;Turner,ASimon;Les,CliffordM;Fyhrie,DavidP
有证据表明，骨组织中的损伤、粘弹性刚度特性和术后力学特性相关。我们的目的是测试缺陷的存在是否会对骨的表观粘弹性产生影响。我们的第二个目标是检查缺陷取向对表观粘弹性的影响，并利用动态力学分析（DMA）作为无损检测损伤的手段。使用了从6只Warhill绵羊桡骨的颅皮质加工的皮质骨梁（2 × 2 × 19 mm）。将样本放置在DMA机器中，并使用三点弯曲配置在1-10 Hz的频率范围内进行储能模量（E1）和损耗因子（tan δ）的基线测量，一次用于头尾方向的载荷，一次用于内外侧方向的载荷。计算头尾/内外侧测量比值，作为tan δ和E1各向异性的测量值。在每个射束中心的尾部表面上切割一个薄的贯穿厚度的宏观切口后，重复振荡测试。使用双因素重复测量方差分析，然后使用Tukey检验，以组（头尾、中外侧、切迹头尾和切迹中外侧测量）和频率作为因素。采用回归分析和协方差分析方法研究了粘弹性参数与频率之间的关系。在引入缺陷之前，前后侧和内外侧测量的Tan δ和E1无差异（分别为p> 0.8和p = 1）。在存在缺陷的情况下，对于头尾测量，tan δ显著增加（p< 0.003），而E1显著降低（p< 0.001）。在将缺陷引入骨组织之前，Tan δ和E1在测试方向上几乎各向同性。引入缺陷导致tan δ和E1各向异性增加。缺口的存在导致tan δ各向异性随着频率的增加而显著增加。总之，我们已经证明，皮质骨组织表现出不同的明显的粘弹性行为的缺陷的存在下，并取决于缺陷的方向。我们的发现，一个缺口的存在和它的方向可以检测到的无损DMA表明，在体内技术可能会发展为检测皮质骨损伤。© 2004 Wiley Periodicals，Inc. J Biomed Mater Res 69A：124-130，2004
There is evidence that damage, viscoelastic stiffness properties, and postyield mechanical properties are related in bone tissue. Our objective was to test whether presence of a flaw would have an influence on the apparent viscoelastic properties of bone. Examining the effect of flaw orientation on apparent viscoelastic properties and utilization of dynamic mechanical analysis (DMA) as a nondestructive means for detection of damage were our secondary objectives. Cortical bone beams (2 × 2 × 19 mm) machined from the cranial cortex of the radii of six Warhill sheep were used. The specimens were placed in a DMA machine and baseline measurements of storage modulus (E1) and loss factor (tan δ), once for loads in the craniocaudal and once in the mediolateral directions, were performed using a three‐point bending configuration for a frequency range of 1–10 Hz. Craniocaudal/mediolateral measurement ratio was calculated as a measure of anisotropy for tan δ andE1. After cutting a thin through‐thickness macroscopic notch on the caudal surface at the center of each beam, oscillatory tests were repeated. Two‐way repeated measures analysis of variance followed by Tukey's test was used with group (craniocaudal, mediolateral, notched craniocaudal, and notched mediolateral measurements) and frequency as factors. Regression analysis and analysis of covariance were used for examining the relationship between viscoelastic parameters and frequency. Tan δ andE1 were not different between craniocaudal and mediolateral measurements before the flaw was introduced (p> 0.8 andp= 1, respectively). In the presence of the flaw, tan δ was significantly increased (p< 0.003) whereasE1 was significantly reduced (p< 0.001) for craniocaudal measurements. Tan δ andE1 were nearly isotropic in the tested directions before the introduction of a flaw into the bone tissue. Introduction of a flaw resulted in increased tan δ andE1 anisotropy. Presence of a notch resulted in a significant increase in tan δ anisotropy with increasing frequency. In conclusion, we have demonstrated that cortical bone tissue exhibits a different apparent viscoelastic behavior in the presence of a flaw and depending on the flaw's orientation. Our finding that the presence of a notch and its orientation can be detected by nondestructive DMA suggests thatin vivotechniques may be developed for detection of cortical bone damage. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 69A: 124–130, 2004