PCL Substitution is not Essential for Excellent Postoperative Outcomes in TKA

This study was performed to compare the postoperative range of knee motion and functional outcome of total knee replacements performed with a PCL-substituting knee prosthesis compared with an ultracongruent PCL-sacrificing design. Two hundred nine patients underwent primary total knee arthroplasties by the same surgeon utilizing the same surgical approach and a hyperflexion postoperative rehab protocol. One hundred twenty-one knees with a posterior stabilized (PS) design and 88 knees with a highly conforming, PCL-sacrificing, ultracongruent (UC) design were retrospectively reviewed with a minimum 2-year follow-up period. The age, sex, and preoperative Knee Society scores were equivalent for both groups. There was a significant improvement in knee flexion, ROM, Knee Score, and function score within each group. Comparatively, the postoperative mean total ROM was slightly higher with the PS design (PS = 119.9 ± 10.8°, UC = 116.7 ± 10.2°; P = .04). However, the two patient groups were the same postoperatively in terms of the improvement in ROM, knee score, function score, satisfaction level, and several postoperative activity metrics. The slight improvement in postoperative knee flexion with the PCL-substituting design may be attributed to the benefits of mechanical substitution of the function of the PCL or possibly by the slightly greater preoperative range of motion. Surprisingly, there was no clear categorical evidence proving superiority of posterior stabilization in PCL-sacrificing TKA.