Liu D, Manske S L, Kontulainen S A, Tang C, Guy P, Oxland T R, McKay H A
Department of Orthopaedics, University of British Columbia, Vancouver, Canada.
Osteoporos Int. 2007 Jul;18(7):991-7. doi: 10.1007/s00198-007-0325-0. Epub 2007 Feb 1.
We studied the relations between bone geometry and density and the mechanical properties of human cadaveric tibiae. Bone geometry, assessed by MRI and pQCT, and bone density, assessed by DXA, were significantly associated with bone's mechanical properties. However, cortical density assessed by pQCT was not associated with mechanical properties.
The primary objective of this study was to determine the contribution of cross-sectional geometry (by MRI and pQCT) and density (by pQCT and DXA) to mechanical properties of the human cadaveric tibia.
We assessed 20 human cadaveric tibiae. Bone cross-sectional geometry variables (total area, cortical area, and section modulus) were measured with MRI and pQCT. Cortical density and areal BMD were measured with pQCT and DXA, respectively. The specimens were tested to failure in a four-point bending apparatus. Coefficients of determination between imaging variables of interest and mechanical properties were determined.
Cross-sectional geometry measurements from MRI and pQCT were strongly correlated with bone mechanical properties (r(2) range from 0.55 to 0.85). Bone cross-sectional geometry measured by MRI explained a proportion of variance in mechanical properties similar to that explained by pQCT bone cross-sectional geometry measurements and DXA measurements.
We found that there was a close association between geometry and mechanical properties regardless of the imaging modality (MRI or pQCT) used.
我们研究了人体尸体胫骨的骨几何结构和密度与力学性能之间的关系。通过MRI和pQCT评估的骨几何结构以及通过DXA评估的骨密度与骨的力学性能显著相关。然而，通过pQCT评估的皮质骨密度与力学性能无关。
本研究的主要目的是确定横截面几何结构（通过MRI和pQCT）和密度（通过pQCT和DXA）对人体尸体胫骨力学性能的贡献。
我们评估了20具人体尸体胫骨。用MRI和pQCT测量骨横截面几何变量（总面积、皮质面积和截面模量）。分别用pQCT和DXA测量皮质骨密度和面骨密度。在四点弯曲装置中对标本进行破坏测试。确定感兴趣的成像变量与力学性能之间的决定系数。
MRI和pQCT的横截面几何测量与骨力学性能密切相关（r²范围为0.55至0.85）。MRI测量的骨横截面几何结构解释的力学性能方差比例与pQCT骨横截面几何测量和DXA测量解释的比例相似。
我们发现，无论使用何种成像方式（MRI或pQCT），几何结构与力学性能之间都存在密切关联。
