Watanabe Mutsumi, Kuriyama Shinichi, Nakamura Shinichiro, Nishitani Kohei, Tanaka Yoshihisa, Sekiguchi Kazuya, Ito Hiromu, Matsuda Shuichi
Department of Orthopaedic Surgery, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
Department of Orthopaedic Surgery, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
Clin Biomech (Bristol). 2019 Mar;63:85-94. doi: 10.1016/j.clinbiomech.2019.02.018. Epub 2019 Feb 27.
In general, the flexion gap is larger than the extension gap with posterior cruciate ligament-sacrificing total knee arthroplasty. Several methods compensate for an excessive flexion gap, but their effects are unknown. The purpose of this study was to compare three methods to compensate for an increased flexion gap.
In this study, squatting in knees with excessive (4 mm) and moderate (2 mm) flexion gaps was simulated in a computer model. Differences in knee kinematics and kinetics with joint line elevation, setting the femoral component in flexion, and using a larger femoral component as compensatory methods were investigated.
The rotational kinematics during flexion with setting the femoral component in flexion were opposite to those in the other models. Using a larger femoral component resulted in the most physiological motion. The peak anterior translation was 10 mm in the joint line elevation model compared with approximately 6 mm in the other models. In the joint line elevation model, patellofemoral contact stress was excessively increased at 90° of knee flexion. In contrast, tibiofemoral contact stress was higher during knee extension with setting the femoral component in flexion due to anterior impingement. There were few differences in the effect of the three compensatory methods with a moderate flexion gap.
A larger femoral component should be used to compensate for an excessive flexion gap because it has less negative impact on posterior cruciate ligament-sacrificing total knee arthroplasty, whereas any compensation method might be acceptable for a moderate flexion gap.
一般来说，在牺牲后交叉韧带的全膝关节置换术中，屈膝间隙大于伸膝间隙。有几种方法可用于补偿过大的屈膝间隙，但其效果尚不清楚。本研究的目的是比较三种补偿增加的屈膝间隙的方法。
在本研究中，在计算机模型中模拟了屈膝间隙过大（4毫米）和适中（2毫米）的膝关节下蹲情况。研究了通过抬高关节线、将股骨组件设置为屈曲以及使用更大的股骨组件作为补偿方法时膝关节运动学和动力学的差异。
将股骨组件设置为屈曲时，屈曲过程中的旋转运动学与其他模型相反。使用更大的股骨组件产生的运动最接近生理状态。在抬高关节线模型中，最大前向平移为10毫米，而其他模型中约为6毫米。在抬高关节线模型中，屈膝90°时髌股关节接触应力过度增加。相比之下，由于前方撞击，将股骨组件设置为屈曲时，膝关节伸展过程中的胫股关节接触应力更高。对于适中的屈膝间隙，三种补偿方法的效果差异不大。
应使用更大的股骨组件来补偿过大的屈膝间隙，因为它对牺牲后交叉韧带的全膝关节置换术的负面影响较小，而对于适中的屈膝间隙，任何补偿方法可能都是可以接受的。
