The End of the Cam and Post: Why We Upgraded Our Knee Implants
A review of the kinematic data driving the shift away from traditional knee arthroplasty designs.
Total knee arthroplasty (TKA) continues to be a widely successful procedure by alleviating pain and restoring function for patients with degenerative disease of the knee. However, a significant number of patients continue to be dissatisfied with their TKA. Although patient dissatisfaction is multifactorial, the inability of total knee implants to restore native knee kinematics is likely a contributing factor.
Historically, the orthopedic world has debated between two main camps of knee design: posterior-stabilized and cruciate-retaining. Traditional posterior-stabilized total knee implant designs use a cam and post mechanism, which promotes roll back of the femur on the tibia during knee flexion. In contrast, traditional cruciate-retaining knee implants have a round-on-flat articulation that relies on an intact posterior cruciate ligament (PCL).
