Robotic arm-assisted posterior-stabilised total knee arthroplasty reduces the amount of tibial bone resection thickness without increasing the rate of postoperative flexion contracture in varus knees in the short term: Comparison with image-free navigated total knee arthroplasty

Background: This study aimed to compare the bone resection thickness, rate of minimal thickness insert usage, and postoperative range of motion (ROM) between robotic and navigated total knee arthroplasty (TKA). Methods: Fifty consecutive posterior-stabilised (PS) robotic TKA and 50 case-controlled PS navigated TKA were enroled. Bone resection thickness, rate of minimal thickness insert usage, and postoperative flexion contracture over 5 degrees were statistically compared. Results: The tibial bone resection thickness was significantly thinner in robotic TKA. The insert thickness was significantly lower, and the rate of minimal thickness insert usage was significantly higher in robotic TKA. The ROM at 3 months postoperatively and the rate of postoperative flexion contracture were comparable between the two groups. Conclusion: Robotic TKA can reduce the tibial bone resection thickness and increase the rate of minimal thickness insert usage without increasing postoperative flexion contracture as compared with navigated TKA.