Martin Daniel E, Severns Anne E, Kabo J M J Michael
David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.
J Biomech. 2004 Aug;37(8):1289-93. doi: 10.1016/j.jbiomech.2003.12.009.
Mechanical tests of bone provide valuable information about material and structural properties important for understanding bone pathology in both clinical and research settings, but no previous studies have produced applicable non-invasive, quantitative estimates of bending stiffness. The goal of this study was to evaluate the effectiveness of using peripheral quantitative computed tomography (pQCT) data to accurately compute the bending stiffness of bone. Normal rabbit humeri (N=8) were scanned at their mid-diaphyses using pQCT. The average bone mineral densities and the cross-sectional moments of inertia were computed from the pQCT cross-sections. Bending stiffness was determined as a function of the elastic modulus of compact bone (based on the local bone mineral density), cross-sectional moment of inertia, and simulated quasistatic strain rate. The actual bending stiffness of the bones was determined using four-point bending tests. Comparison of the bending stiffness estimated from the pQCT data and the mechanical bending stiffness revealed excellent correlation (R2=0.96). The bending stiffness from the pQCT data was on average 103% of that obtained from the four-point bending tests. The results indicate that pQCT data can be used to accurately determine the bending stiffness of normal bone. Possible applications include temporal quantification of fracture healing and risk management of osteoporosis or other bone pathologies.
骨骼的力学测试可提供有关材料和结构特性的宝贵信息，这对于在临床和研究环境中理解骨骼病理学非常重要，但以前没有研究能够产生适用的非侵入性定量弯曲刚度估计值。本研究的目的是评估使用外周定量计算机断层扫描（pQCT）数据准确计算骨骼弯曲刚度的有效性。使用pQCT对8只正常兔的肱骨中段进行扫描。从pQCT横截面计算平均骨矿物质密度和横截面惯性矩。弯曲刚度被确定为密质骨弹性模量（基于局部骨矿物质密度）、横截面惯性矩和模拟准静态应变率的函数。使用四点弯曲试验确定骨骼的实际弯曲刚度。比较从pQCT数据估计的弯曲刚度和机械弯曲刚度，发现两者具有极好的相关性（R2 = 0.96）。pQCT数据得出的弯曲刚度平均为四点弯曲试验所得弯曲刚度的103%。结果表明，pQCT数据可用于准确确定正常骨骼的弯曲刚度。可能的应用包括骨折愈合的时间量化以及骨质疏松症或其他骨骼疾病的风险管理。
