Effect of Tibial Resection on Coronal and Sagittal Gap Balancing in Robot-Assisted Total Knee Arthroplasty.

Introduction: The essence of total knee arthroplasty (TKA) is achieving optimal soft tissue balance. While robotic systems provide real-time gap feedback, the isolated impact of tibial resection on gap symmetry remains underexplored. Objective: To evaluate the association between tibial resection and coronal and sagittal gap balancing in patients undergoing robot-assisted TKA (RATKA). Materials and Methods: A retrospective study of 1137 knees using the VELYS system was conducted. Medial-lateral gap differences in extension and flexion were compared before and after tibial resection. Mechanical alignment correction and insert size distribution were also analyzed. Results: Tibial resection was associated with improved extension gap symmetry in 88.4% of cases and flexion symmetry in 63.9%. Mean hip-knee-ankle correction was 5.2°, with 99.8% achieving neutral alignment. No meaningful correlation was found between post-tibial gaps and insert size. Conclusion: Tibial resection was associated with improved gap symmetry and mechanical axis correction during RATKA using a tibia-first workflow. These findings support the potential role of early tibial resection in optimizing gap balance; however, prospective multicenter studies incorporating long-term clinical and functional outcomes are needed to validate these observations.