三维组架螺钉与微创钢板固定SandersⅢ型跟骨骨折的有限元分析

背景：经皮复位加压固定的三维组架螺钉内固定在治疗SandersⅢ型跟骨骨折上已经取得了满意的临床疗效，但在生物力学方面是否可以达到微创钢板内固定的稳定性，以及对比之后的优势与缺点还不得而知。目的：通过有限元分析方法探讨不同内固定装置对SandersⅢ型跟骨骨折的固定效果。方法：选择1名26岁成年健康男性志愿者，根据其跟骨CT数据制作SandersⅢ型跟骨骨折有限元模型。选用经皮微创三维组架螺钉、跗骨窦微创钢板分别固定跟骨骨折模型，分别施加350,700 N纵向载荷，分析2种模型的位移、应力分布情况，比较各种模型的稳定性。结果与结论：(1)三维组架螺钉模型中骨块与内植物的峰值应力明显低于微创钢板模型，三维组架螺钉模型中骨块与内植物的平均应力也明显低于微创钢板模型；(2)2种模型的最大位移均位于后距关节面内侧，三维组架螺钉模型的最大位移小于微创钢板模型；(3)微创钢板模型前突骨块与内侧骨块的纵向位移更小，三维组架螺钉模型内侧骨块与中段骨块的横向与垂直位移更小；(4)提示2种内固定模型均能提供满意的固定效果，其中三维组架螺钉模型使应力分布更均匀、骨块综合位移更小，能提供更好的横向与垂直稳定性...

Finite element analysis of three-dimensional frame screws and minimally invasive plate for fixation of Sanders III calcaneal fractures

BACKGROUND: Satisfactory clinical results have been achieved in the treatment of Sanders III calcaneal fractures by percutaneous compression fixation with three-dimensional frame screws. However, whether the stability of minimally invasive plate internal fixation can be achieved in terms of biomechanics, and the advantages and disadvantages after comparison are still unknown. OBJECTIVE: To investigate the fixation effect of different internal fixation devices on Sanders III calcaneal fractures by finite element analysis. METHODS: A finite element model of Sanders III calcaneal fracture was made based on CT data of a 26-year-old healthy male volunteer. The calcaneal fracture models were fixed by minimally invasive three-dimensional frame screws and minimally invasive Y-plate. The longitudinal loads of 350 and 700 N were applied respectively. The displacement and stress distribution of the two models were analyzed, and the stability of each model was compared. RESULTS AND CONCLUSION: (1) The peak stress of bone block and implant in the minimally invasive three-dimensional frame screw model was significantly lower than that in the minimally invasive minimally invasive plate model. The average stress of bone block and implant in the three-dimensional frame screw model was also significantly lower than that in the minimally invasive plate model. (2) The maximum displacement of the two models was located at the medial side of the articular surface of the posterior talus, and the maximum displacement of the three-dimensional frame screw model was smaller than that of the minimally invasive plate model. (3) The longitudinal displacement between the anterior fragment and the medial fragment of the minimally invasive plate model was smaller, and the transverse and vertical displacement between the medial fragment and the middle fragment of the three-dimensional group screw model was smaller. (4) It is concluded that both of the two internal fixation models can provide satisfactory fixation effect. The three-dimensional frame screw model can provide better transverse and vertical stability with more uniform stress distribution and smaller comprehensive displacement of bone fragments, while the minimally invasive plate has more advantages in maintaining longitudinal stability. © 2024, Publishing House of Chinese Journal of Tissue Engineering Research. All rights reserved.