Carretta Roberto, Stüssi Edgar, Müller Ralph, Lorenzetti Silvio
Institute for Biomechanics, ETH Zurich, Vladimir-Prelog-Weg 3, 8093 Zurich, Switzerland.
Biomed Res Int. 2015;2015:457371. doi: 10.1155/2015/457371. Epub 2015 Jan 28.
Clinical studies indicate that bone mineral density correlates with fracture risk at the population level but does not correlate with individual fracture risk well. Current research aims to better understand the failure mechanism of bone and to identify key determinants of bone quality, thus improving fracture risk prediction. To get a better understanding of bone strength, it is important to analyze tissue-level properties not influenced by macro- or microarchitectural factors. The aim of this pilot study was to identify whether and to what extent material properties are correlated with mechanical properties at the tissue level. The influence of macro- or microarchitectural factors was excluded by testing individual trabeculae. Previously reported data of mechanical parameters measured in single trabeculae under tension and bending and its compositional properties measured by Raman spectroscopy was evaluated. Linear and multivariate regressions show that bone matrix quality but not quantity was significantly and independently correlated with the tissue-level ultimate strain and postyield work (r = 0.65-0.94). Principal component analysis extracted three independent components explaining 86% of the total variance, representing elastic, yield, and ultimate components according to the included mechanical parameters. Some matrix parameters were both included in the ultimate component, indicating that the variation in ultimate strain and postyield work could be largely explained by Raman-derived compositional parameters.
临床研究表明，在人群层面骨矿物质密度与骨折风险相关，但与个体骨折风险的相关性不佳。当前的研究旨在更好地理解骨骼的破坏机制，并确定骨质量的关键决定因素，从而改善骨折风险预测。为了更好地理解骨强度，分析不受宏观或微观结构因素影响的组织水平特性很重要。这项初步研究的目的是确定在组织水平上材料特性与力学性能是否相关以及相关程度如何。通过测试单个小梁排除了宏观或微观结构因素的影响。评估了先前报道的在拉伸和弯曲状态下单个小梁的力学参数测量数据以及通过拉曼光谱测量的其组成特性。线性和多变量回归表明，骨基质质量而非数量与组织水平的极限应变和屈服后功显著且独立相关（r = 0.65 - 0.94）。主成分分析提取了三个独立成分，解释了总方差的86%，根据所包含的力学参数分别代表弹性、屈服和极限成分。一些基质参数同时包含在极限成分中，表明极限应变和屈服后功的变化在很大程度上可以由拉曼衍生的组成参数解释。
