ABSTRACT
Objective:To investigate the safety and effectiveness of robot-assisted total knee arthroplasty (TKA).Methods:From August 2021 to March 2022, the data of 69 patients who received robot-assisted TKA for inflammatory disease of knee in 6 hospitals were collected, including 24 males and 45 females, aged 52±6 years (range, 46-72 years), including 53 cases of knee osteoarthritis,10 cases of rheumatoid arthritis, and 6 cases of traumatic arthritis. Imaging data examination of patients was completed according to the multicenter specification. Preoperatively, the patient's CT data were extracted before surgery and a personalized prosthesis positioning plan was designed by the robotic system to determine the prosthesis size, lower limb force lines, and femoral and tibial osteotomy volumes; intraoperatively, the osteotomy template was robotically controlled to complete the osteotomy according to the prosthesis positioning plan, and the intraoperative osteotomy volumes were measured to verify the accuracy of the robot-assisted TKA osteotomy with the preoperative planning. Postoperatively, the lateral angle of the distal femur, the medial angle of the proximal tibia and the hip-knee-ankle angle were measured in the coronal plane according to radiographs; the postoperative outcome was evaluated 3 months after operation, using the American Knee Society score (KSS), including the KSS knee score and functional score.Results:The operative time was 97.3±2.3 min (range, 80-110 min) and the amount of bleeding was 320.0±6.2 ml (range, 300-350 ml) in 69 patients. Three months after operation, the mean range of motion of knee joint was increased from 82.2°±1.1° before surgery to 119.7°±0.8° after surgery ( t=27.65, P<0.001), and the line of force of lower limb was improved from 160.9°±0.5° before surgery to 178.0°±0.2° after surgery ( t=32.03, P<0.001). KSS-knee score increased from 54.8±0.7 points before operation to 85.0±0.5 points after operation, and KSS-functional score increased from 56.5±0.7 points before operation to 85.9±0.4 points after operation, the difference was statistically significant ( t=35.45, 36.58, P<0.001). The proportion of patients with intraoperative femoral and tibial osteotomies within 2 mm osteotomy error compared with preoperative planning was 97% for the lateral tibial plateau, 100% for the medial tibial plateau, 100% for the lateral distal femur, 99% for the medial distal femur, 93% for the lateral posterior femoral condyle, and 100% for the medial posterior femoral condyle; The proportion of patients with postoperative anteroposterior X-ray measurement angle error within 3° was: 100.0% for the distal lateral femoral angle, 100.0% for the proximal medial tibial angle, and 100% for the hip-knee-ankle angle. No complications occurred in all patients except for one case in which fat liquefaction occurred in the postoperative wound. Conclusion:Robot-assisted TKA is a safe and effective surgical method for the treatment of inflammatory disease of knee with accurate prosthesis installation and good postoperative recovery of lower limb alignment.