To find the relationships between internal fixation parameters and biomechanical indexes with least number of runs, a regression orthogonal approach is proposed to establish surrogate models of different biomechanical indexes. Firstly, a simplified model of transverse femoral shaft fracture is built, and varieties of geometric sizes for plates and screws configurations are combined based on orthogonal array. Next, the biomechanical indexes of different combinations are calculated through finite element analysis (FEA). Furthermore, surrogate models are developed with the aid of regression orthogonal analysis. Finally, with comparison of biomechanical indexes obtained from the surrogate models and FEA results, highly coincident results validate the surrogate models. The number of combinations is greatly reduced compared with that arranged by comprehensive regression analysis. The surrogate models show acceptable results for predicating biomechanical indexes, whose relative deviation is less than 9%. Moreover, the results obtained by the surrogate models suggest that working length and thickness of the plate are the significant parameters on the maximum plate stress and maximum intra-fragmentary movement respectively, which complies with previous studies. The regression orthogonal method presented in this study can greatly reduce the number of experimental runs for investigating the biomechanics of internal fixation for femoral shaft fracture. The method can also be applied to other scenarios of fractures or even the other biomedical fields to provide a comprehensive insight into biomedical relationships with least number of trials.

为了找到最少固定次数的内固定参数与生物力学指标之间的关系，提出了一种回归正交方法来建立不同生物力学指标的替代模型。首先，建立了股骨横干骨折的简化模型，并基于正交阵列将各种几何尺寸的钢板和螺钉配置进行了组合。接下来，通过有限元分析（FEA）计算不同组合的生物力学指标。此外，借助回归正交分析开发了替代模型。最后，通过比较从替代模型获得的生物力学指标和有限元分析结果，高度一致的结果验证了替代模型。与通过综合回归分析安排的组合相比，组合的数量大大减少了。替代模型显示出预测生物力学指标的可接受结果，其相对偏差小于9％。此外，通过替代模型获得的结果表明，板的工作长度和厚度分别是最大板应力和最大内部碎片运动的重要参数，与先前的研究相符。本研究提出的回归正交方法可以大大减少用于研究股骨干骨折内固定生物力学的实验次数。