Maderbacher Guenther, Keshmiri Armin, Springorum Hans R, Maderbacher Hermann, Grifka Joachim, Baier Clemens
Department of Orthopedic Surgery, University Medical Center Regensburg, Bad Abbach, Germany.
Department of Mechanical Engineering, Montanuniversität Leoben, Leoben, Austria.
J Arthroplasty. 2017 Sep;32(9):2869-2877. doi: 10.1016/j.arth.2017.03.055. Epub 2017 Apr 1.
Physiological tibiofemoral kinematics have been shown to be important for good knee function after total knee arthroplasty (TKA). The purpose of the present study was to investigate the influence of component rotation on tibiofemoral kinematics during knee flexion. We asked which axial component alignment best reconstructs physiological tibiofemoral kinematics and which combinations should be avoided.
Ten healthy cadaveric knees were examined. By means of a navigational device, tibiofemoral kinematics between 0° and 90° of flexion were assessed before and after TKA using the following different rotational component alignment: femoral components: ligament balanced, 6° internal, 3° external rotation, and 6° external rotation in relation to the posterior condylar line; tibial components: self-adapted, 6° internal rotation, and 6° external rotation.
Physiological tibiofemoral kinematics could be partly reconstructed by TKA. Ligament-balanced femoral rotation and 6° femoral external rotation both in combination with 6° tibial component external rotation, and 3° femoral external rotation in combination with 6° tibial component internal rotation or self-aligning tibial component were able to restore tibial longitudinal rotation. Largest kinematical differences were found for the combination femoral component internal and tibial component external rotations.
From a kinematic-based view, surgeons should avoid internal rotation of femoral components. However, even often recommended combinations of rotational component alignment (3° femoral external and tibial external rotation) significantly change tibiofemoral kinematics. Self-aligning tibial components solely restored tibiofemoral kinematics with the combination of 3° femoral component of external rotation. For the future, navigational devices might help to axially align components to restore patient-specific and natural tibiofemoral kinematics.
生理状态下的胫股运动学已被证明对全膝关节置换术（TKA）后良好的膝关节功能很重要。本研究的目的是探讨组件旋转对膝关节屈曲过程中胫股运动学的影响。我们研究了哪种轴向组件对线能最佳重建生理胫股运动学，以及哪些组合应避免。
对10个健康尸体膝关节进行检查。通过导航设备，在TKA前后，使用以下不同的旋转组件对线评估0°至90°屈曲之间的胫股运动学：股骨组件：韧带平衡、相对于后髁线内旋6°、外旋3°和外旋6°；胫骨组件：自适应、内旋6°和外旋6°。
TKA可部分重建生理胫股运动学。韧带平衡的股骨旋转和股骨外旋6°与胫骨组件外旋6°组合，以及股骨外旋3°与胫骨组件内旋6°或自对线胫骨组件组合，能够恢复胫骨纵向旋转。股骨组件内旋和胫骨组件外旋组合的运动学差异最大。
从基于运动学的观点来看，外科医生应避免股骨组件内旋。然而，即使是经常推荐的旋转组件对线组合（股骨外旋3°和胫骨外旋）也会显著改变胫股运动学。自对线胫骨组件仅与股骨组件外旋3°组合时能恢复胫股运动学。未来，导航设备可能有助于轴向对齐组件，以恢复患者特异性和自然的胫股运动学。
