Jenny Jean-Yves, Boeri Cyril, Picard Frédéric, Leitner François
Centre de Traumatologie et d'Orthopédie, Illkirch, France.
Comput Aided Surg. 2004;9(4):161-5. doi: 10.3109/10929080500095517.
The restoration of a normal mechanical axis of the lower limb following total knee prosthesis (TKP) depends on the accuracy of the intra-operative measurement of the femoro-tibial angle. We have studied the reproducibility of intra-operative measurement of the coronal mechanical femoro-tibial axis with the OrthoPilot (Aesculap, Tuttlingen, Germany) non-image-based navigation system.
A consecutive series of 20 TKP (Aesculap SEARCH Evolution prosthesis) implanted by the same surgical team of two senior orthopedic surgeons was analyzed. They used a non-image-based navigation system that allows the mechanical axes of the femur and tibia to be defined with a kinematic analysis. The operating surgeon and assistant surgeon performed the kinematic analysis twice and once, respectively, and measured coronal mechanical femoro-tibial angles in maximal extension and at 90 degrees flexion without varus or valgus stress.
The mean intra-observer variation in the measurement of the coronal mechanical femoro-tibial angle in maximal extension was 0.1 degrees (SD = 0.7 degrees). The mean intra-observer variation in the measurement of the coronal mechanical femoro-tibial angle at 90 degrees of knee flexion was 0.2 degrees (SD = 0.6 degrees). The mean inter-observer variation in the measurement of the coronal mechanical femoro-tibial angle in maximal extension was 0.1 degrees (SD = 0.7 degrees). The mean inter-observer variation in the measurement of the coronal mechanical femoro-tibial angle in maximal extension was 0.0 degrees (SD = 0.6 degrees). There were no significant differences and a high correlation between all paired intra- and inter-observer measurements.
This system allows high reproducibility of the intra-operative measurement of the mechanical axes of the lower limb by a non-image-based kinematic registration of the hip, knee and ankle centers.
全膝关节置换术（TKP）后下肢正常机械轴的恢复取决于股骨 - 胫骨角术中测量的准确性。我们研究了使用OrthoPilot（德国图特林根蛇牌）非图像导航系统术中测量冠状面机械股骨 - 胫骨轴的可重复性。
分析了由两位资深骨科医生组成的同一手术团队连续植入的20例TKP（蛇牌SEARCH Evolution假体）。他们使用了一种非图像导航系统，该系统通过运动学分析来确定股骨和胫骨的机械轴。主刀医生和助手医生分别进行了两次和一次运动学分析，并在最大伸展位和90度屈曲位无内翻或外翻应力的情况下测量冠状面机械股骨 - 胫骨角。
最大伸展位时冠状面机械股骨 - 胫骨角测量的观察者内平均差异为0.1度（标准差 = 0.7度）。膝关节屈曲90度时冠状面机械股骨 - 胫骨角测量的观察者内平均差异为0.2度（标准差 = 0.6度）。最大伸展位时冠状面机械股骨 - 胫骨角测量的观察者间平均差异为0.1度（标准差 = 0.7度）。最大伸展位时冠状面机械股骨 - 胫骨角测量的观察者间平均差异为0.0度（标准差 = 0.6度）。所有配对的观察者内和观察者间测量之间均无显著差异且相关性高。
该系统通过对髋、膝和踝关节中心进行非图像运动学配准，可实现术中下肢机械轴测量的高可重复性。
