Goldstein S A, Goulet R, McCubbrey D
Orthopaedic Research Laboratories, University of Michigan, Ann Arbor 48109-0486.
Calcif Tissue Int. 1993;53 Suppl 1:S127-32; discussion S132-3. doi: 10.1007/BF01673421.
The mechanical properties of trabecular bone have been shown to vary significantly with age, anatomic location, and metabolic condition. Efforts towards predicting its behavior have been extensive, and significant relationship between measures of density and mechanical integrity have been reported. Unfortunately, the significant heterogeneity in trabecular bone anisotropy contributes to significant unexplained variance in its strength and modulus when predicted using scalar measures of mass or density. As a result, numerous investigators have attempted to include measures of architecture in an effort to more rigorously investigate potential physiologic optimization strategies, as well as account for the increased fragility associated with advancing age. In our laboratories we have utilized a unique three-dimensional, microcomputed tomography system to measure trabecular plate thickness, trabecular plate separation, trabecular plate number, surface to volume ratio, bone volume fraction, anisotropy, and connectivity in isolated specimens of trabecular bone. The results of these studies demonstrate that in normal bone, more than 80% of the variance in its mechanical behavior can be explained by measures of density and orientation. The independent measures of connectivity and trabecular plate number were found to be significantly correlated with bone volume fraction, suggesting a potential strategy in the formation of trabecular bone. It might be hypothesized, however, that the relationship between bone volume fraction and connectivity may be substantially altered under conditions associated with aging, fragility, or metabolic bone disease. This hypothesis would be consistent with the histologic evidence of reduced connectivity in osteopenic patients.
已证明小梁骨的力学性能会随年龄、解剖位置和代谢状况而显著变化。预测其行为的研究工作广泛开展，且有报道称密度测量与力学完整性之间存在显著关系。遗憾的是，小梁骨各向异性的显著异质性导致在使用质量或密度的标量测量进行预测时，其强度和模量存在显著的无法解释的差异。因此，众多研究人员试图纳入结构测量，以便更严格地研究潜在的生理优化策略，并解释与年龄增长相关的骨折风险增加的原因。在我们的实验室中，我们利用了一种独特的三维微型计算机断层扫描系统来测量小梁骨分离、小梁骨数量、表面体积比、骨体积分数、各向异性和连通性。这些研究结果表明，在正常骨骼中，其力学行为超过80%的差异可以通过密度和取向测量来解释。发现连通性和小梁骨数量的独立测量与骨体积分数显著相关，这表明小梁骨形成中存在一种潜在策略。然而，可以假设，在与衰老、脆性或代谢性骨病相关的情况下，骨体积分数与连通性之间的关系可能会发生显著改变。这一假设与骨质疏松症患者连通性降低的组织学证据一致。
