Mechanical analysis of anterior and posterior cruciate ligament during knee flexion and extension
膝关节屈伸时前后交叉韧带的力学分析

摘要

目的 分析膝关节屈伸时前后交叉韧带的生物力学特征。方法 纳入1名健康成年男性，在1.5TMRI机、医学影像学软件、有限元分析软件等设备的支持下制作膝关节三维有限元模型。分别模拟膝关节屈曲0°、30°、60°、90°时不同载荷条件下膝关节前、后交叉韧带的应力分布情况及大小；同时，取后交叉韧带试样，驱动机器对其施加拉伸应力，直至式样断裂时统计拉伸最大载荷及应力。结果 膝关节屈曲30°时前后位移、远近位移最大，屈曲90°时内外位移最大，屈曲60°时内外翻角度最大，屈曲30°时内外旋角度最大。膝关节在股骨后向134N载荷时，屈曲30°时前交叉韧带承受应力最大，屈曲90°时后交叉韧带承受应力最大；内翻10Nm载荷、外翻10Nm载荷及10Nm内翻+5Nm内旋载荷时，屈曲0°时前交叉韧带承受应力最大，屈曲90°时后交叉韧带承受应力最大。膝关节拉伸状态下拉伸最大载荷为367.65N，后交叉韧带承受的最大应力为19.34MPa。结论 膝关节不同屈曲状态下其承受的应力不同，损伤风险不同；同时后交叉韧带的拉伸性能良好，可预防膝关节扭伤。

Abstract

Objective To analyze the biomechanical characteristics of anterior and posterior cruciate ligament during knee flexion and extension.
Methods: A healthy adult male was included in this study. A 3D finite element model of knee joint was made with the support of 1.5TMRI machine, medical imaging software, finite element analysis software and other equipment. The stress distribution and magnitude of anterior and posterior cruciate ligaments of knee joints were simulated under different load conditions when knee joints were flexed at 0°, 30°, 60° and 90°. At the same time, the posterior cruciate ligament samples were taken, and the machine was driven to apply tensile stress to them. The maximum tensile load and stress were counted until the pattern was broken.
Results: The anterior and posterior displacements were the largest at 30° flexion, the internal and external displacements were the largest at 90° flexion, the internal and external rotation angles were the largest at 60° flexion, and the internal and external rotation angles were the largest at 30° flexion. When the knee joint was subjected to 134N posterior femoral load, the maximum stress was sustained by the ACL at 30° flexion and the maximum stress was sustained by the ACL at 90° flexion. Under varus 10Nm load, valgus 10Nm load, and 10Nm varus +5Nm internal rotation load, the ACL bore the maximum stress at 0° flexion and the posterior cruciate ligament bore the maximum stress at 90° flexion. The maximum tensile load of the knee joint was 367.65N, and the maximum stress of the posterior cruciate ligament was 19.34mpa.
Conclusion  : The stress of knee joint under different flexion conditions is different and the risk of injury is different. At the same time, the stretching performance of the posterior cruciate ligament is good, which can prevent knee sprain.