The PCL significantly affects the functional outcome of total knee arthroplasty.

This study tests the hypothesis that patients receiving a posterior cruciate ligament (PCL)-retaining prosthesis have no difference in functional outcome compared to those receiving a cruciate-sacrificing, posterior-stabilized (PS) design. Forty-nine patients underwent a total knee arthroplasty (TKA), performed by a single surgeon using the same implant design with either a PCL-retaining or a PS tibial insert. Each patient completed a self-administered, validated Total Knee Function Questionnaire as well as the SF-36. At 1-year follow-up, each patient's range of motion and Knee Society knee score were measured. There were no statistically significant differences between the 2 groups using the traditional measures of function following total knee replacement, including overall satisfaction with surgery. However, the TKFQ revealed that patients with PS knees reported greater functional limitations in squatting, kneeling, and gardening. Our results suggest that with the specific implant used in this study, substitution for the PCL with a spine and cam mechanism may not fully restore the functional capacity of the intact PCL, particularly in high-demand activities that involve deep flexion.