Factors affecting postoperative range of motion after total knee arthroplasty.

One hundred thirty five patients with osteoarthritis who underwent total knee arthroplasty (TKA) were evaluated to determine whether specific pre- and postoperative variables were correlated with the postoperative range of motion. Age, sex, pre- and postoperative range of motion, pre- and postoperative Knee Society scores, intraoperative patellar thickness before and after resurfacing, pre- and postoperative radiographic patellar height (as determined by the Insall-Salvati and Blackburn-Peel ratios), and preoperative radiographic alignment were recorded for each patient. Regression analysis was performed to identify whether any variables were correlated with the postoperative range of motion or Knee Society scores. The only variable that was significantly correlated with postoperative range of motion was the preoperative range of motion. This study suggests that among the variables evaluated, the preoperative range of motion was the only significant predictor of postoperative range of motion.