Kabel J, Odgaard A, van Rietbergen B, Huiskes R
Department of Orthopaedic Surgery, Aarhus University Hospital, Denmark.
Bone. 1999 Feb;24(2):115-20. doi: 10.1016/s8756-3282(98)00164-1.
This study addresses the possible significance of trabecular connectivity for the mechanical quality of cancellous bone. A total of 141 cubic trabecular bone specimens collected from autopsy material from 56 individuals without any known bone or metastatic diseases were used. Age variation was in the range of 14-91 years and a wide range of trabecular architecture was found. Each specimen was three-dimensionally reconstructed with a voxel size of either 20 or 25 microm. Using the detailed three-dimensional reconstructions as input for microstructural finite-element models, the complete elastic properties of the trabecular architecture were obtained and maximum and mean stiffness could be calculated. Volume fraction and true three-dimensional architectural measurements of connectivity density and surface density were determined. Connectivity density was determined in an unbiased manner by the Euler number, which is a topological property. Using multiple regression analysis it was found that volume fraction explained by far the greatest part (84%-94%) of the variation in both mean and maximum stiffness. When connectivity density and surface density were included, the correlations increased marginally to 89%-95%. Noticeably negative regression coefficients were found for connectivity density. The results suggest that, in normal cancellous bone, the connectivity density has very limited value for assessment of elastic properties by morphological variables, but if a relation exists then stiffness decreases with increasing connectivity.
本研究探讨了骨小梁连通性对松质骨力学性质的潜在意义。总共使用了141个立方松质骨标本，这些标本取自56名无任何已知骨骼或转移性疾病个体的尸检材料。年龄范围为14 - 91岁，发现了广泛的骨小梁结构。每个标本以20或25微米的体素大小进行三维重建。将详细的三维重建作为微观结构有限元模型的输入，获得骨小梁结构的完整弹性特性，并计算最大和平均刚度。确定了体积分数以及连通性密度和表面密度的真实三维结构测量值。连通性密度通过欧拉数以无偏方式确定，欧拉数是一种拓扑特性。通过多元回归分析发现，体积分数解释了平均刚度和最大刚度变化的绝大部分（84% - 94%）。当纳入连通性密度和表面密度时，相关性略有增加，达到89% - 95%。发现连通性密度的回归系数明显为负。结果表明，在正常松质骨中，连通性密度对于通过形态学变量评估弹性特性的价值非常有限，但如果存在某种关系，那么刚度会随着连通性增加而降低。
