EPMEDBOT robotic-assisted total knee arthroplasty amplifies the advantage of intraoperative dynamic gap balance and alignment monitoring – a prospective randomized controlled and single center study

Abstract

BACKGROUND AND PURPOSE: Total knee arthroplasty (TKA) remains the primary treatment for end-stage knee osteoarthritis, with surgical navigation robots showing significant clinical benefits. This study aimed to evaluate and compare the radiographic and clinical outcomes of robot-assisted TKA (RATKA) using the EPMEDBOT-RATKA system against manual TKA. METHODS: A single-center study recruited 78 participants, with 66 patients randomized into two groups: 32 underwent RATKA and 34 underwent manual TKA. Key clinical outcomes, such as the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Knee Society Score (KSS), and range of motion (ROM), were assessed and compared between the groups. Radiographic measures, including preoperative and postoperative hip-knee-ankle angle (HKA), the proportion of patients achieving HKA ≤ 3°, and postoperative prosthetic alignment, were also analyzed. Additionally, perioperative HKA axis values and flexion-extension gaps were dynamically monitored. RESULTS: The RATKA group had significantly longer tourniquet times and greater intraoperative blood loss compared to the manual TKA group. Both groups exhibited improved postoperative knee function, ROM, KSS, and WOMAC scores at follow-up, though no significant differences were observed between the groups. RATKA showed superior postoperative mechanical alignment (p < 0.05) and less variability in intraoperative alignment monitoring (p < 0.05). Furthermore, RATKA resulted in smaller discrepancies in flexion-extension and medial-lateral gaps compared to manual TKA (p < 0.05). Although the RATKA group displayed better postoperative prosthetic alignment angles, the difference between the groups was not statistically significant. CONCLUSION: The EPMEDBOT-RATKA system is a dependable TKA tool, providing benefits in dynamic gap balancing, alignment monitoring, and prosthetic positioning. While short-term clinical outcomes were similar between the two approaches, the enhanced alignment precision achieved with RATKA may contribute to improved long-term implant survival. Extended follow-up studies are necessary to confirm these potential long-term advantages.