The posterior cruciate ligament in total knee arthroplasty.

The purpose of this study was to answer 2 questions: Does the posterior cruciate ligament (PCL) produce femoral rollback in a single-design, cruciate-sparing total knee arthroplasty (TKA)? Does the PCL prevent posterior tibial displacement when it is retained after a single-design, cruciate-sparing TKA? Knee kinematics and limits of motion were measured with the knees in the following states: (1) intact knee, (2) anterior cruciate-deficient knee, (3) PCL-retaining total knee of a single design (TKA), (4) PCL-retaining TKA with PCL cut, and (5) PCL-substituting TKA. Femoral rollback was then calculated from the above data. The results showed that the PCL was able to prevent posterior translation and maintain femoral rollback when it was preserved during TKA. Therefore, the PCL can be functional after TKA, in a single-design, cruciate-sparing TKA. When the PCL was cut, significant changes in knee kinematics were observed.