Bone fracture, formation and adaptation are related to mechanical strains in bone. Assessing bone stiffness and strain distribution under different loading conditions may help predict diseases and improve surgical results by determining the best conditions for long-term functioning of bone-implant systems. In this study, an experimentally wide range of loading conditions (56) was used to cover the directional range spanned by the hip joint force. Loads for different stance configurations were applied to composite femurs and assessed in a material testing machine. The experimental analysis provides a better understanding of the influence of the bone inclination angle in the frontal and sagittal planes on strain distribution and stiffness. The results show that the surface strain magnitude and stiffness vary significantly under different loading conditions. For the axial compression, maximal bending is observed at the mid-shaft, and bone stiffness is also maximal. The increased inclination leads to decreased stiffness and increased magnitude of maximum strain at the distal end of the femur. For comparative analysis of results, a three-dimensional, finite element model of the femur was used. To validate the finite element model, strain gauges and digital image correlation system were employed. During validation of the model, regression analysis indicated robust agreement between the measured and predicted strains, with high correlation coefficient and low root-mean-square error of the estimate. The results of stiffnesses obtained from multi-loading conditions experiments were qualitatively compared with results obtained from a finite element analysis of the validated model of femur with the same multi-loading conditions. When the obtained numerical results are qualitatively compared with experimental ones, similarities can be noted. The developed finite element model of femur may be used as a promising tool to estimate proximal femur strength and identify the best conditions for long-term functioning of the bone-implant system in future study.

骨折、形成和适应与骨中的机械应变有关。通过确定骨植入系统长期功能的最佳条件，评估不同负载条件下的骨刚度和应变分布可能有助于预测疾病并改善手术结果。在这项研究中，实验中广泛的负载条件 (56) 用于覆盖髋关节力跨越的方向范围。对复合材料股骨施加不同姿态配置的载荷，并在材料试验机中进行评估。实验分析提供了更好地理解前平面和矢状平面中骨骼倾斜角对应变分布和刚度的影响。结果表明，在不同的加载条件下，表面应变大小和刚度变化显着。对于轴向压缩，在中轴处观察到最大弯曲，并且骨骼刚度也最大。增加的倾斜导致股骨远端的刚度降低和最大应变的幅度增加。为了对结果进行比较分析，使用了股骨的三维有限元模型。为了验证有限元模型，应变仪和数字图像相关系统被采用。在模型验证期间，回归分析表明测量和预测的应变之间具有很强的一致性，估计的相关系数高，均方根误差低。从多载荷条件实验获得的刚度结果与从具有相同多载荷条件的验证股骨模型的有限元分析获得的结果进行定性比较。当获得的数值结果与实验结果进行定性比较时，可以注意到相似之处。开发的股骨有限元模型可用作估计股骨近端强度和确定骨植入系统在未来研究中长期功能的最佳条件的有前途的工具。