Posterior Stabilized Total Knee Arthroplasty

The posterior cruciate ligament (PCL) in total knee arthroplasty (TKA) functions to prevent posterior translation of the tibia and aids in femoral roll-back1. Roll-back allows for increased quadriceps lever arm and more efficient use of extensor musculature, permitting more normal stair climbing. Because of this, PCL retaining knees have the advantage of maintenance of ligamentous proprioception, load transfer by the native PCL and anteriorposterior stability. However, retaining the PCL also has several disadvantages. Surgical exposure of the tibia, gap balancing and reliance on diseased ligament morphology make consistent TKA results difficult. The posterior stabilized design in TKA was introduced in the mid-1970s. Surgeons who use this system believed that the results obtained are more consistent because they do not have to rely on abnormal PCL morphology. Consequently, exposure, joint line restoration and appropriate balancing of the knee are easier with PCL stabilized designs. These components are a popular treatment for patients requiring primary TKA. Improvements in implant design, a technically easier procedure in the face of deformity, restoration of knee kinematics and reported very good long-term outcomes may all be reasons for the increased use of this design.