Effect of 45° versus 90° Knee Flexion during Wound Closure in Total Knee Arthroplasty: A Randomized Trial with 3-Month Follow-Up

Background: Knee positioning during wound closure in total knee arthroplasty (TKA) affects the postoperative outcomes. Previous studies have compared knee flexion at 90 degrees with knee extension. Objective: To evaluate the outcomes of knee flexion at 45 degrees versus 90 degrees during wound closure in TKA. Materials and Methods: The present study was a prospective, randomized clinical trial that included 58 patients undergoing TKA with posteriorstabilized prostheses. The participants were randomly assigned to one of two groups with 29 patients in the 45-degree knee flexion group (Group I) and 29 patients in the 90-degree knee flexion group (Group II). Postoperative outcomes were assessed at three months and included pain, knee function recovery, patellar height, and complications. Results: Three months after TKA, no statistically significant differences in pain were found between the groups (p=0.874). Group I reported a mean pain score of 2.03±1.92 compared with 2.24±2.18 in Group II. Additionally, there were no statistically significant differences in knee function recovery between the groups (p=0.389 in the Forgotten Joint Score-12, p=0.611 in the Oxford Knee Score, and p=0.556 in range of motion). No significant differences were observed in the patellar height (p=0.848) or complications. Conclusion: There were no significant differences in postoperative pain, knee function recovery, patellar height, or complications between the 45-degree and 90-degree knee flexion positions during TKA wound closure. Both positions were equally effective and safe.