目的 探讨三维组架螺钉与环形钢板对Sanders ⅢAB型跟骨骨折的生物力学稳定性的影响。方法 收集1名26岁志愿者跟骨CT和MRI数据，建立Sanders ⅢAB型跟骨骨折的三维有限元模型，分别使用三维组架螺钉与环形钢板固定，施加700 N纵向载荷，比较不同模型骨块及内固定应力与位移变化情况。结果 在700 N纵向载荷下，两组模型骨块最大位移以及骨块与内固定最大应力均集中于后距关节面内固定与骨折线相交处。三维组架螺钉模型与环形钢板模型骨块整体位移相近。相较于环形钢板模型，三维组架螺钉模型骨块及内固定的最大应力和平均应力更小，位移与应力变化情况更接近完整跟骨模型。结论 Sanders ⅢAB型跟骨骨折固定时，三维组架螺钉与环形钢板两种固定方式均能提供良好稳定性。三维组架螺钉的生物力学性能优于环形钢板，更符合生物力学特点。

Objective To investigate the effects of three-dimensional (3D) screws and circular plates on the biomechanical stability of Sanders ABⅢ calcaneal fractures. Methods Calcaneal computed tomography (CT) and magnetic resonance imaging (MRI) data from a 26-year-old volunteer were collected to establish a 3D finite element model of a Sanders IIIAB calcaneal fracture fixed with 3D screws and circular plates. A longitudinal load of 700 N was applied to compare the variations in the stress, displacement of the bone block, and internal fixation in the different models. Results Under 700 N longitudinal loads, the maximum displacement of the bone block and the maximum stress of the bone block and internal fixation were concentrated at the intersection of the posterior talar articular plane internal fixation and fracture line. The overall displacements of the bone blocks in the 3D screw and circular plate models were similar. Compared with the circular plate model, the maximum and average stresses of the bone block and internal fixation in the 3D screw model were lower, and the displacement and stress changes of the 3D screw model were closer to those of the complete calcaneal bone model. Conclusions In the fixation of Sanders IIIAB calcaneal fractures, both 3D screw and circular plate fixation methods can provide good stability. The biomechanical properties of the 3D screws were better than those of the circular plates, which is consistent with the biomechanical characteristics.

上海市浦东新区卫生健康委员会2020年度卫生科技项目（PW2020A-43），上海市浦东新区卫生健康委员会临床特色学科建设资助项目（PWYts2021-05）