PCL Substitution is not Essential for Excellent Postoperative Outcomes in TKA

Abstract

performed. Tibiofemoral angles, patellar tilt, and patellar congruence angles were measured preoperatively and postoperatively. There were no patellar subluxations, dislocations, or complications related to the patellofemoral joint in the postoperative period. Patellar tilt improved from a mean of 7.98 preoperatively to 3.88 postoperatively and the congruence angle improved from 13.98 preoperatively to 5.18 postoperatively. Seventeen patients had 10 mm of medial patellar lift-off intraoperatively (mean, 14 mm; range, 10-22 mm). Patients with 10 mm of intraoperative lift-off improved from 9.98 tilt preoperatively to 6.68 postoperatively. Patients with no intraoperative lift-off changed from 6.38 to 2.98. Although the two groups were statistically different, the amount of change from preoperative to postoperative was not different between the groups. There was no difference in preoperative or postoperative congruence angles between patients with or without intraoperative patellar lift-off. There was no correlation between preoperative tibiofemoral alignment and patellar lift-off intraoperatively. Based on the brule of no thumb,Q the lateral release rate in this series would have been at least 18%. Patients with medial patellar lift-off at the time of arthroplasty do not appear to require lateral release to yield acceptable postoperative patellofemoral alignment.