有限元分析在桡骨远端骨折中的应用

屈任伸 梁锦成 黄彬铖

[摘要]目的 探讨有限元分析在桡骨远端骨折中的应用效果。方法 采集正常桡骨CT薄层扫描图像，凭借有限元分析软件Ansys l0.0，三维重建软件Mimics 10.01构建桡骨远端有限元模型，并在此基础上构建桡骨远端骨折模型，采用传统小夹板固定实现紧固的目标。设定骨折端不稳移位的压缩，拉伸载荷分别是66.7 N，内外旋载荷是22 N，同时对常规杉树皮夹板的应力发布情况进行分析。结果 压缩情况下，夹板系统应力的最大值为29.89 Mpa;拉伸情况下，夹板系统应力的最大值为25.48 Mpa;外旋情况下，夹板系统应力的最大值及位移分别为32.69 Mpa;内旋情况下，夹板系统应力的最大值及位移分别为30.33 Mpa。结论 建模方式与实际桡骨力学性能的三维有限元模型非常接近，且可以将患者真实的临床情况体现出来，并在此基础上，对桡骨结构及材料力学性能进行深入研究，可确定桡骨在骨折时应力应变与夹板固定后的改变，进而为夹板设计的完善及优化提供参考。

[关键词]桡骨远端骨折：传统小夹板;外固定术;有限元分析

[中图分类号] R683          [文献标识码] A          [文章编号] 1674-4721（2019）8（a）-0086-03

[Abstract] Objective To explore the application effect of finite element analysis in distal radius fracture. Methods The normal humeral CT thin-layer scan image was acquired， and the finite element model of the distal radius was constructed by the finite element analysis software Ansys l0.0 and the three-dimensional reconstruction software Mimics 10.01， based on this， a distal radius fracture model was constructed， which was fixed by traditional small splint. The compression of the unstable displacement of the fracture end was set. The tensile load was 66.7 N and the internal and external rotation load was 22 N. At the same time， the stress release of the conventional cedar bark splint was analyzed. Results In the case of compression， the maximum stress of the splint system was 29.89 Mpa. Under tension， the maximum stress of the splint system was 25.48 Mpa. Under the circumstance of external rotation， the maximum stress and displacement of the splint system were 32.69 Mpa， respectively. In the case of internal rotation， the maximum stress and displacement of the splint system were 30.33 Mpa， respectively. Conclusion The modeling method is very close to the three-dimensional finite element model of the actual mechanical properties of the radius， and can reflect the real clinical situation of the patients. On this basis， the mechanical properties of the radius structure and materials are deeply studied. The stress-strain changes of the radius during fracture and the changes after splint fixation can be determined， and then splints can be set up. It provides reference for the improvement and optimization of the design.

[Key words] Distal radius fracture; Traditional small splint; External fixation; Finite element analysis

健康人的橈骨远端关节面向掌侧的倾斜范围为10°～15°，向尺侧倾斜的范围为20°～25°（尺倾角）。桡骨远端具备尺，掌，桡，背4个面，背侧凸起，掌侧光滑凹陷，共具备4个骨性腿沟，下尺桡关节是前臂旋转的枢纽，其由尺侧面构成。若桡骨远端发生骨折的情况，不仅桡骨下端的关节面会改变角度，而且腿部肌肉会出现扭曲的情况。倘若复位的情况相对较差，会影响患者的腕与手指功能[1]。因此，桡骨远端若发生骨折的情况，务必运用科学的固定方式及器械，固定物的位置、手术后的制动设备会在很大程度上影响骨折患者的临床治疗。在桡骨远端骨折试验的实际应用阶段，采用有限元的方式针对腕关节的形变、骨小梁以及应力进行分析及研究。患者的骨折部位被固定后，应结合患者骨骼与邻近软组织对关节部的力学特性，采用合适的固定方法对患者进行治疗，同时分析各项体位与功能锻炼对骨折断端产生的作用及影响，应用现代化的计算机技术进行数据的输出，能为患者的骨折治疗奠定数据基础。有限元分析方式的骨折仿真方式具备较强的吸引力，且治疗效果较佳。有限元分析方式应用模拟手术，能有效处理内外固定后对关节所致的不良反应，使动物实验统计周期长、繁琐的不足之处得到弥补，现报道如下。