腓骨近端骨折对胫骨后外侧平台骨折影响的有限元分析△

A finite element analysis of the effect of proximal fibular fracture on posterolateral tibial plateau fractures

摘要:

[目的]通过有限元分析，探讨腓骨近端对胫骨后外侧平台骨折的力学影响。[方法]收集 1 名志愿者胫腓骨 CT 数据，导入 SolidWorks 软件，模拟 3 种不同胫腓骨形态，分为正常组（normal control, NC）、胫骨后外平台骨折钢板内固定腓骨完整组 （posterolateral tibial plateau fracture with plate fixation and intact fibula, IF）、胫骨后外平台骨折钢板内固定腓骨骨折组 （pos- terolateral tibial plateau fracture with plate fixation and fibular fracture, FF）。在施加 250 N、500 N、1 000 N 轴向载荷状态下，模拟日常活动中不同受力情况下内固定受力及胫骨骨折模型的位移情况。[结果]与 NC 组相比，IF 组与 FF 组钢板与螺钉的 Von Mises 应力随着载荷的增大显著增加（P＜0.05）。在 250 N、500 N、1 000 N 载荷下，IF 组钢板 [(20.3±1.5) MPa vs (28.5±1.6) MPa, P＜0.001; (42.3±1.6) MPa vs (59.4±1.7) MPa, P＜0.001; (90.5±7.8) MPa vs (123.3±15.9) MPa, P=0.003] 及螺钉 [(24.4±3.1) MPa vs (35.7± 2.5) MPa, P＜0.001; (50.2±7.9) MPa vs (70.30±9.6) MPa, P=0.007; (101.1±15.7) MPa vs (143.7±16.4) MPa, P=0.003] Von Mises 应力均小于 FF 组。随着载荷的增大，两组骨折块位移及内侧胫骨平台位移均显著增加（P＜0.05）；在相同载荷下，IF 组骨折块的位移及内侧胫骨平台位移均显著小于 FF 组（P＜0.05）。[结论] 在胫骨平台后外侧骨折中，完整的腓骨可以提升钢板、螺钉的整体轴向刚度，使外侧骨折块及内侧胫骨平台更为稳定，对骨折的愈合有促进作用。

Abstract:

[Objective] To investigate the mechanical effect of proximal fibula on posterior lateral tibial plateau fracture by finite element analysis. [Methods] The CT data of a volunteer's tibia and fibula were collected and imported into SolidWorks software to simulate 3 conditions, including the normal control (NC), posterolateral tibial plateau fracture with plate fixation and intact fibula group (IF) and posterolateral tibial plateau fracture with plate fixation and fibular fracture (FF). Under 250 N, 500 N and 1 000 N axial loads, the displacement of the model of internal fixation and tibial fracture and under daily activities was measured. [Results] Compared with that of NC group, the Von Mises stress of plates and screws in IF group and FF group was significantly increased with the increase of load (P＜0.05). Under loads of 250 N, 500 N and 1 000 N, the IF group proved significantly less than the FF group in terms Von Mises stress of the plate [(20.3±1.5) MPa vs (28.5±1.6) MPa, P＜0.001; (42.3±1.6) MPa vs (59.4±1.7) MPa, P＜0.001; (90.5±7.8) MPa vs (123.3±15.9) MPa, P=0.003] and the screw [(24.4±3.1) MPa vs (35.7±2.5) MPa, P＜0.001; (50.2±7.9) MPa vs (70.3±9.6) MPa, P=0.007; (101.1±15.7) MPa vs (143.7±16.4) MPa, P= 0.003]. With the increase of load, the displacement of fracture fragment and the displacement of medial tibial plateau in both groups were significantly increased (P＜0.05). Under the same load, the displacement of fracture fragment and medial tibial plateau in IF group were significantly less than the FF group (P＜0.05). [Conclusion] In posterolateral tibial plateau fractures, the intact fibula does improve the overall axial stiffness of plates and screws, make lateral fracture fragment and medial tibial plateau more stable, and promote the healing of fracture.