The purpose of this study was to quantify the effect of total knee replacement (TKR) alignment on in-vivo knee function and loading in a unique patient cohort who have been identified as having a high rate of component mal-alignment. Post-TKR (82.4 ± 6.7 months), gait analysis was performed on 25 patients (27 knees), to calculate knee kinematics and kinetics. For a step activity, video fluoroscopic analysis quantified in-vivo implant kinematics. Frontal plane lower-limb alignment was defined by the Hip-Knee-Ankle angle (HKA) measured on long leg static X-rays. Transverse plane component rotation was calculated from computed tomography scans. Sagittal plane alignment was defined by measuring the flexion angle of the femoral component and the posterior tibial slope angle (PTSA). For gait analysis, a more varus HKA correlated with increased peak and dynamic joint kinetics, predicting 47.6% of Knee Adduction Angular Impulse variance. For the step activity, during step-up and single leg loaded, higher PTSA correlated with a posterior shift in medial compartment Anterior-Posterior (AP) translation. During step-down, higher PTSA correlated with reduced lateral compartment AP translation with a posterior shift in AP translation in both compartments. A more varus HKA correlated with a more posterior medial AP translation and inter-component rotation was related to transverse plan range of motion. This in-vivo study found that frontal plane lower-limb alignment had a significant effect on joint forces during gait but had minimal influence on in-vivo implant kinematics for step activity. PTSA was found to influence in-vivo TKR translations and is therefore an important surgical factor.

这项研究的目的是为了量化全膝关节置换（TKR）对准对独特的患者队列中体内膝关节功能和负荷的影响，该队列已被确定具有较高的组件错位率。TKR后（82.4±6.7个月），对25例患者（27个膝盖）进行了步态分析，以计算膝盖的运动学和动力学。对于一步活动，视频荧光透视分析定量了体内植入物运动学。额骨下肢的对准是通过对长腿静态X射线测量的髋关节，膝关节和踝关节角（HKA）定义的。横向平面旋转是通过计算机断层扫描来计算的。通过测量股骨组件的屈曲角度和胫骨后倾斜角（PTSA）定义矢状面对齐。为了进行步态分析，HKA的内翻程度与峰值和动态关节动力学增加相关，预测膝内收角冲量变化为47.6％。对于踏步活动，在踏步和单腿加载过程中，较高的PTSA与内侧腔室前后移位（AP）的后移相关。在降压过程中，较高的PTSA与减少的侧房室AP翻译相关，且两个房室中AP翻译的后移。内翻角更大的HKA与后内侧AP的更平移相关，并且组件间旋转与横向平面运动范围有关。这项体内研究发现，额叶下肢对齐对步态中的关节力有显着影响，但对步态活动的体内植入物运动学影响最小。