Physicians

Stop the Slide

Instead of exhibiting rollback, most traditional knees flex to approximately 20° and then slide forward.⁶ This paradoxical motion is observed in almost all total knees on the market, affecting both posterior cruciate ligament (PCL) retaining knees and (to a lesser extent) posterior stabilized (PS) knees.⁷

This paradoxical slide forward may make the patient feel unstable, resulting in a lack of confidence in the knee and an altered gait to avoid the feeling of instability.⁸ In addition, this uncontrolled motion may result in increased polyethylene wear and decreased flexion due to early impingement of the femur on the tibia.⁹