Abstract: BACKGROUND: With the rise of robotic-assisted total knee arthroplasty, its advantages in implant positioning accuracy have garnered significant attention. However, current evidence remains inconclusive regarding whether robotic-assisted total knee arthroplasty is superior to conventional total knee arthroplasty in improving postoperative joint range of motion, prosthesis revision rates, limb alignment, and patient satisfaction. 
OBJECTIVE: To investigate the differences in clinical function and radiographic outcomes between Mako robotic-assisted total knee arthroplasty and conventional total knee arthroplasty, as well as their clinical significance.
METHODS: A retrospective analysis was conducted on 66 osteoarthritis patients who underwent Mako robotic-assisted total knee arthroplasty (robotic-assisted group) at the China-Japan Friendship Hospital between January 2023 and September 2024. A matched cohort of 59 patients who underwent conventional total knee arthroplasty (conventional total knee arthroplasty group) was selected based on age, gender, and body mass index. The operation time, blood loss, tourniquet usage time, and clinical outcomes of the two groups before, and 3, 6, and 12 months after surgery were recorded, including Hospital for Special Surgery knee score, Western Ontario and McMaster Universities Osteoarthritis Index, Knee Society Score (functional score), and knee range of motion. Full-length X-rays of both lower limbs in the anteroposterior weight-bearing position were taken before and 1 week after surgery, and the hip-knee-ankle angle, valgus correction angle, lateral distal femoral angle, lateral proximal femoral angle, and medial proximal tibial angle were measured and compared between both groups of patients. 
RESULTS AND CONCLUSION: (1) The robotic-assisted group had a longer operative time but a shorter tourniquet time compared with the conventional total knee arthroplasty group, with comparable blood loss between groups. (2) At one week postoperatively, range of motion improved in both groups, with a slightly greater improvement in the conventional total knee arthroplasty group (P > 0.05). (3) Hospital for Special Surgery scores indicated similar functional improvements postoperatively, with no significant differences (P > 0.05). At one year, the robotic-assisted group had significantly higher Knee Society Score function scores compared with the conventional total knee arthroplasty group (P < 0.05). Western Ontario and McMaster Universities Osteoarthritis Index scores showed improvements in both groups, but the robotic-assisted group had superior outcomes at six months and one year compared with the conventional total knee arthroplasty group (P < 0.05). (4) Radiographic analysis demonstrated improved lower limb alignment and optimal prosthesis positioning in all patients, with no severe adverse events during follow-up. (5) Imaging measurement displayed that the robotic-assisted group showed significant improvements in hip-knee-ankle angle, medial proximal tibial angle, and lateral proximal femoral angle postoperatively (P < 0.05), whereas valgus correction angle and lateral distal femoral angle remained unchanged (P > 0.05). In the conventional total knee arthroplasty group, hip-knee-ankle angle and medial proximal tibial angle significantly improved (P < 0.05), while valgus correction angle, lateral proximal femoral angle, and lateral distal femoral angle remained unchanged (P > 0.05). No significant differences were observed in postoperative radiographic indices between the two groups (P > 0.05). except for valgus correction angle and lateral proximal femoral angle, the preoperative and postoperative changes in other values were not significantly different (P > 0.05). (6) The incidence of postoperative complications was not significantly different between groups (P > 0.05). (7) These findings suggest that Mako robotic-assisted total knee arthroplasty offers superior intraoperative precision in angular alignment, limb axis correction, and soft tissue balancing compared with conventional total knee arthroplasty, enhancing the accuracy and personalization of bone resection and implant placement. Postoperative lower limb alignment and clinical outcomes were non-inferior to conventional total knee arthroplasty, demonstrating promising potential for broader clinical application.

Key words: robotic-assisted, total knee arthroplasty, imaging, lower limb alignment, range of motion, knee joint function