Batra Sahil, Sugumar Pon Aravindhan A, Kumar Vijay, Malhotra Rajesh
Department of Orthopaedics, All India Institute of Medical Sciences (AIIMS), New Delhi, 110029, India.
J Clin Orthop Trauma. 2020 Aug 21;13:70-73. doi: 10.1016/j.jcot.2020.08.014. eCollection 2021 Feb.
Total knee arthroplasty (TKA) usually provides good pain relief and improved function but has generally been unable to fully restore normal knee kinematics. Does Medial or Lateral Pivot TKA designs guide us to native knee kinematics needs to be elucidated?
Kinematic assessment of 13 knees with Medial Pivot TKA and 13 knees with Lateral Pivot TKA was done. The subjects were asked to perform step-up and weight bearing deep knee bend exercise under fluoroscopy for kinematic assessment. Patellar Tendon Angle (PTA) was measured after correcting f luoroscopic images for distortion against Knee Flexion Angle (KFA).
During the weight bearing deep knee bend, the average active maximum flexion achieved with Medial Pivot design was 113.8 ͦ as compared to 102.9 ͦ with Lateral Pivot design. There was no significant difference in PTA in step up and deep knee bend exercise between both the designs.
The kinematic assessment of both the Medial and Lateral Pivot TKA designs revealed linear trend of PTA with increasing KFA as described for normal knee. Both the designs were able to achieve functional knee range of motion.
全膝关节置换术（TKA）通常能有效缓解疼痛并改善功能，但一般无法完全恢复正常的膝关节运动学。内侧或外侧旋转平台TKA设计是否能引导我们满足自然膝关节运动学需求，这有待阐明。
对13例采用内侧旋转平台TKA的膝关节和13例采用外侧旋转平台TKA的膝关节进行了运动学评估。受试者在透视引导下进行上台阶和负重深蹲运动以进行运动学评估。在对透视图像进行失真校正后，测量髌腱角（PTA）与膝关节屈曲角度（KFA）的关系。
在负重深蹲过程中，内侧旋转平台设计的平均主动最大屈曲角度为113.8°，而外侧旋转平台设计为102.9°。两种设计在上台阶和深蹲运动中的髌腱角无显著差异。
内侧和外侧旋转平台TKA设计的运动学评估显示，髌腱角随膝关节屈曲角度增加呈线性趋势，与正常膝关节情况相符。两种设计均能实现膝关节的功能活动范围。
