Orthopaedic Bioengineering Research Laboratory, Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523, USA.
Bone. 2010 Apr;46(4):1108-13. doi: 10.1016/j.bone.2010.01.366. Epub 2010 Jan 14.
Computed tomography (CT) data can be employed with respect to determining mechanical properties and has been used to predict parameters such as elastic modulus, yield strength, and ultimate strength of intact bone. Micro-computed tomography (muCT) possesses the resolution capable of detecting apparent bone density in extremely local regions and can characterize the trabecular structure. It has been asserted that this micro-structure is susceptible to micro-buckling and bending, which has a controversial role in predicting the global mechanical properties of bone. The current study measured the mechanical properties of relatively high apparent density bone from the equine distal third metacarpal. The mechanical properties were correlated with trabecular morphology parameters and apparent densities of localized regions obtained with muCT. These data were used to test two hypotheses: (1) accounting for trabecular bending using trabecular morphology parameters would provide better global mechanical property predictions than using only apparent density, and (2) regions of low apparent density dominate the overall mechanical behavior and provide greater correlation to the measured mechanical properties than regions of high apparent density. The data indicated that accounting for trabecular bending with morphological parameters resulted in stronger correlations to mechanical properties than correlations that relied only on apparent density (r2= 0.91 versus r2= 0.81). Low apparent density regions were more strongly correlated with mechanical properties than high apparent density regions (r2= 0.85 versus r2= 0.77), demonstrating the importance of selecting appropriate regions when attempting to predict mechanical properties from CT data.
计算机断层扫描（CT）数据可用于确定机械性能，并已被用于预测完整骨骼的弹性模量、屈服强度和极限强度等参数。微计算机断层扫描（micro-CT，muCT）具有能够检测局部区域明显骨密度的分辨率，并能够对小梁结构进行特征描述。有人断言，这种微结构容易发生微屈曲和弯曲，这对预测骨骼的整体力学性能有争议的作用。本研究测量了马属动物远第三掌骨相对高表观密度骨的力学性能。将力学性能与使用 micro-CT 获得的局部区域的小梁形态参数和表观密度相关联。这些数据用于检验两个假设：（1）使用小梁形态参数来考虑小梁弯曲会比仅使用表观密度提供更好的整体力学性能预测，（2）低表观密度区域主导整体力学行为，并与测量的力学性能比高表观密度区域具有更大的相关性。数据表明，与仅依赖于表观密度的相关性相比，使用形态参数考虑小梁弯曲可与力学性能更紧密相关（r2=0.91 对 r2=0.81）。低表观密度区域与力学性能的相关性比高表观密度区域更强（r2=0.85 对 r2=0.77），这表明在尝试从 CT 数据预测力学性能时，选择适当的区域非常重要。
