In Vivo Kinematics Evaluation in Flexion of Patients Implanted With Primary TKA

摘要

Fluoroscopy along with image registration techniques is widely used to study the in vivo kinematic behavior observed in total knee arthroplasties (TKAs). This study provides and overview of the basic principles associated with the process and the protocols commonly followed using this technique. A summary of the data collected for more than 2000 patients implanted with 25 different types of TKAs are also provided and compared with the kinematics observed in normal knees. Some of the characteristics of TKA behavior when compared with normal knees include: (1) incidence of reduced posterior translations or paradoxical anterior slide of the femoral condyles with respect to the tibia; (2) reverse axial rotation patterns, where the femur rotates internally relative to the tibial component with increasing flexion; and (3) incidence of condylar lift-off where one of the condyles separate and loses contact. Comparison of patients who achieve higher flexion with those who achieve lower flexion revealed that the condylar contact location remains more posterior in the higher flexing group even at the same flexion angles.