Abstract
First generation condylar knee replacements suffered from two prominent observations: 1) Difficulty in stair climbing, 2) Limited range of motion (ROM).
Improved understanding of knee kinematics, the importance of femoral rollback, and enhanced stability in flexion led to 2 differing schools of thought: Posterior Cruciate ligament retention vs. Posterior Cruciate substitution. The advantages of posterior cruciate substitution include predictable cam-post engagement leading to rollback, predictable ROM, stability during stair climbing, ease of knee balancing regardless of degree of angular deformity, and avoidance of issues such as PCL tightness / laxity at time of index procedure, as well as late ligament disruption leading to late instability.
Evolution has shown that human appendages that no longer served a purpose, slowly shrivel up. As we have seen with the appendix, the coccyx, and the erector pili muscles, these vestigial organs no longer are necessary for daily function and are destined for obsolescence. I submit: the PCL in knee arthroplasty IS THE VESTIGIAL ORGAN: not the posterior stabilizing mechanism!
