Department of Mechanical Engineering, University of California at Davis, One Shields Avenue, Davis, CA, 95616, USA.
Knee Surg Sports Traumatol Arthrosc. 2013 Oct;21(10):2288-95. doi: 10.1007/s00167-012-1987-5. Epub 2012 Apr 5.
Our experience with computer plans of kinematically aligned total knee arthroplasty showed that the anteroposterior (AP) axis of the tibial component when viewed in an axial plane did not consistently intersect either the medial border or the medial 1/3 of the tibial tubercle. The purposes were (1) to determine the variability in the mediolateral location of the tibial tubercle with respect to the medial tibia on the magnetic resonance image (MRI) of the knee and (2) to determine whether the AP axis of the kinematically aligned tibial component intersects either the medial border or the medial 1/3 of the tibial tubercle.
One hundred and fifteen knees in 111 consecutive subjects treated with total knee arthroplasty were studied. The mediolateral location of the tibial tubercle was measured from a magnetic resonance image (MRI) of the knee. The distances between the AP axis of the tibial component and the medial border of the tibial tubercle and between the AP axis and the medial 1/3 of the tibial tubercle were measured from a computer plan of the reconstructed knee.
On the MRI, the medial border of the tibial tubercle varied 15 mm from the medial border of the tibia. On the computer plan, the AP axis of the tibial component in an axial view of the tibia did not intersect either the medial border (p < 0.0001) or the medial 1/3 of the tibial tubercle (p < 0.0001). In 70 and 86 % of knees, the mediolateral distance of the AP axis of the tibial component was 2 mm or greater from the medial border of the tibial tubercle and the medial 1/3 of the tibial tubercle, respectively, which causes a clinically meaningful error in rotation of 5° or more.
Because the mediolateral location of the tibial tubercle varies, the medial border and medial 1/3 of the tibial tubercle are not reliable landmarks when the goal is to kinematically align the rotation of the tibial component on the tibia.
IV.
我们在运用计算机规划的运动学对线全膝关节置换术中发现，在矢状面观察时，胫骨组件的前后（AP）轴并不总是与胫骨的内缘或胫骨结节的内 1/3 相交。目的是：（1）确定膝关节磁共振成像（MRI）上胫骨结节相对于胫骨内侧的横向位置的可变性；（2）确定运动学对线的胫骨组件的 AP 轴是否与胫骨结节的内缘或内 1/3 相交。
研究了 111 例连续接受全膝关节置换术的患者的 115 膝。从膝关节 MRI 上测量胫骨结节的横向位置。从重建膝关节的计算机规划中测量胫骨组件的 AP 轴与胫骨结节内缘以及 AP 轴与胫骨结节内 1/3 之间的距离。
在 MRI 上，胫骨结节的内缘与胫骨内缘相差 15mm。在计算机规划中，胫骨在矢状面的 AP 轴与胫骨结节的内缘（p<0.0001）或胫骨结节的内 1/3（p<0.0001）均不相交。在 70%和 86%的膝关节中，胫骨组件的 AP 轴的横向距离分别距胫骨结节的内缘和内 1/3 为 2mm 或更大，这会导致旋转出现 5°或更大的临床有意义的误差。
由于胫骨结节的横向位置存在差异，因此当目标是在胫骨上进行运动学对线的胫骨组件旋转时，胫骨结节的内缘和内 1/3 不是可靠的标志。
IV 级。
