Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL 60612, USA.
Med Eng Phys. 2012 Apr;34(3):290-8. doi: 10.1016/j.medengphy.2011.07.016. Epub 2011 Aug 12.
To better understand the mechanisms underlying distal radius fracture we have developed finite element models to predict radius bone strain and fracture strength under loading conditions simulating a fall. This study compares experimental surface strains and fracture loads of the distal radius with specimen-specific finite element models to validate our model-generating algorithm. Five cadaveric forearms were instrumented with strain gage rosettes, loaded non-destructively to 300 N, and subsequently loaded until failure. Finite element models were created from computed tomography data; three separate density-elasticity relationships were examined. Fracture strength was predicted for three specimens that failed at the distal radius using six different failure theories. The density-elasticity relationship providing the strongest agreement between measured and predicted strains had a correlation of r=0.90 and a root mean squared error 13% of the highest measured strain. Mean absolute percent error (11.6%) between measured and predicted fracture loads was minimized with Coulomb-Mohr failure theory and a tensile-compressive strength ratio of 0.5. These results suggest that our modeling method is a suitable candidate for the in vivo assessment of distal radius bone strain and fracture strength under fall type loading configurations.
为了更好地理解桡骨远端骨折的机制，我们开发了有限元模型来预测在模拟跌倒的加载条件下桡骨的骨应变和骨折强度。本研究将实验表面应变和桡骨远端的骨折载荷与特定于标本的有限元模型进行比较，以验证我们的模型生成算法。五个尸体前臂用应变片花饰进行了仪器化，在 300N 下进行了非破坏性加载，然后加载直至失效。从 CT 数据创建了有限元模型；研究了三种不同的密度弹性关系。使用六种不同的失效理论预测了三个在桡骨远端失效的标本的骨折强度。提供与测量和预测应变之间最强一致性的密度弹性关系的相关系数为 r=0.90，最高测量应变的均方根误差为 13%。用库仑-莫尔失效理论和拉伸-压缩强度比为 0.5 可将测量和预测的骨折载荷之间的平均绝对百分比误差（11.6%）最小化。这些结果表明，我们的建模方法是在跌倒类型加载配置下评估桡骨骨应变和骨折强度的合适候选方法。
