II Clinic of Orthopaedics and Kinetic Organ Traumatology, Medical University of Gdansk, Gdansk, Poland.
Department of Mechanics of Materials, Faculty of Civil and Environmental Engineering, Gdansk University of Technology, Gdansk, Poland.
PLoS One. 2018 Feb 15;13(2):e0193020. doi: 10.1371/journal.pone.0193020. eCollection 2018.
The purpose of this study was to evaluate the influence of a change in the meniscus cross sectional shape on its position and on the biomechanics of a knee joint.
One main finite element model of a left knee joint was created on the basis of MRI images. The model consisted of bones, articular cartilages, menisci and ligaments. Eight variants of this model with an increased or decreased meniscus height were then prepared. Nonlinear static analyses with a fixed flexion/extension movement for a compressive load of 1000 N were performed. The additional analyses for those models with a constrained medio-lateral relative bone translation allowed for an evaluation of the influence of this translation on a meniscus external shift.
It was observed that a decrease in the meniscus height caused a decrease in the contact area, together with a decrease in the contact force between the flattened meniscus and the cartilage. For the models with an increased meniscus height, a maximal value of force acting on the meniscus in a medio-lateral direction was obtained. The results have shown that the meniscus external shift was approximately proportional to the meniscus slope angle, but that relationship was modified by a medio-lateral relative bone translation. It was found that the translation of the femur relative to the tibia may be dependent on the geometry of the menisci.
The results have suggested that a change in the meniscus geometry in the cross sectional plane can considerably affect not only the meniscal external shift, but also the medio-lateral translation of the knee joint as well as the congruency of the knee joint.
本研究旨在评估半月板横断形状的变化对其位置和膝关节生物力学的影响。
基于 MRI 图像创建了一个左膝关节的主要有限元模型。该模型由骨骼、关节软骨、半月板和韧带组成。然后制备了 8 个半月板高度增加或减小的模型变体。对具有 1000N 压缩载荷的固定屈伸运动进行非线性静态分析。对于那些具有约束的中外侧相对骨平移的模型的附加分析允许评估这种平移对半月板外部移位的影响。
观察到半月板高度降低会导致接触面积减小，同时压扁的半月板与软骨之间的接触力也会减小。对于半月板高度增加的模型，获得了作用于半月板的最大侧向力值。结果表明，半月板外部移位与半月板斜率角度大致成正比，但这种关系受到中外侧相对骨平移的影响。发现股骨相对于胫骨的平移可能取决于半月板的几何形状。
研究结果表明，半月板在横断面上的几何形状变化不仅会显著影响半月板的外部移位，还会影响膝关节的中外侧平移以及膝关节的吻合度。
