Increased microstructural variability is associated with decreased structural strength but with increased measures of structural ductility in human vertebrae.
Increased microstructural variability is associated with decreased structural strength but with increased measures of structural ductility in human vertebrae.
复制标题
微观结构变异性的增加与结构强度的降低有关，但与人类椎骨结构延展性的增加有关。
DOI：
10.1115/1.3148473
复制
发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Yeni,YenerN
中科院分区：
文献类型：
--
作者：
Yerramshetty,Janardhan;Kim,Do-Gyoon;Yeni,YenerN
在所有外部因素相同的情况下，平均密度测量在预测脊柱骨折风险方面缺乏准确性，这可能不仅是因为骨密度(BMD)不是骨强度的完美替代指标，还因为强度本身可能不足以完全表征椎骨的结构性故障。除了骨量外，松质骨结构的区域性差异也会对椎骨的力学性能产生影响。在这项研究中，我们基于体视学分析估计了椎体松质椎体的各种微观结构参数。早期的一项研究表明，椎体内的可变性，以骨体积分数的变异系数(COV/TV)或有限元估计的COV衡量，与椎体强度有很好的相关性。因此，作为我们早期研究的延伸，我们调查了(I)椎体强度与BV/TV和COV的关系是否可以扩展到其他微结构参数的COV和微计算机断层扫描估计的BMD，以及(Ii)微结构参数的COV是否与结构延展性指标相关。与普通的显微结构测量相比，基于CoV的测量与椎体强度和延展性测量的相关性更强。此外，我们的结果支持这样一种假设，即微观结构变异性降低，虽然与强度增加相关，但可能导致结构韧性和延性降低。目前的发现表明，作为临床骨密度的补充，基于变异性的测量方法可以通过改进对骨强度和延展性的预测，在筛选骨折风险方面提供改进。进一步了解微观结构变异背后的生物学机制可能有助于开发新的治疗策略，以改善结构的延展性。
The lack of accuracy in the prediction of vertebral fracture risk from average density measurements, all external factors being equal, may not just be because bone mineral density (BMD) is less than a perfect surrogate for bone strength but also because strength alone may not be sufficient to fully characterize the structural failure of a vertebra. Apart from bone quantity, the regional variation of cancellous architecture would have a role in governing the mechanical properties of vertebrae. In this study, we estimated various microstructural parameters of the vertebral cancellous centrum based on stereological analysis. An earlier study indicated that within-vertebra variability, measured as the coefficient of variation (COV) of bone volume fraction (BV/TV) or as COV of finite element-estimated apparent moduluscorrelated well with vertebral strength. Therefore, as an extension to our earlier study, we investigated (i) whether the relationships of vertebral strength found with COV of BV/TV and COV ofcould be extended to the COV of other microstructural parameters and microcomputed tomography-estimated BMD and (ii) whether COV of microstructural parameters were associated with structural ductility measures. COV-based measures were more strongly associated with vertebral strength and ductility measures than average microstructural measures. Moreover, our results support a hypothesis that decreased microstructural variability, while associated with increased strength, may result in decreased structural toughness and ductility. The current findings suggest that variability-based measures could provide an improvement, as a supplement to clinical BMD, in screening for fracture risk through an improved prediction of bone strength and ductility. Further understanding of the biological mechanisms underlying microstructural variability may help develop new treatment strategies for improved structural ductility.