Alignment of the limb axis in robotic total knee arthroplasty

Traditional methods of limb axis alignment—mechanical and anatomical, kinematic and functional alignment (MA and AA, KA and FA) – are all based on the level and angle of femoral and tibial resection and subsequent balancing of flexion-extension and medial-lateral interosseous gaps by releasing the knee joint capsule and ligaments, which corrects fixed deformities and brings the limb into proper alignment. FA achieves balanced flexion-extension gaps and soft tissue tension by adjusting bone resection, fine-tuning component positions, and reducing soft tissue release using a robotic system. The purpose of this article is to provide a comparative description of various limb axis alignment techniques for total knee arthroplasty using an autonomous robotic platform based on computed tomography image analysis, preoperative individualized planning, and intraoperative soft tissue balance. Materials and Methods: This article, using our own clinical data, presents a step-by-step technique for performing robotic total knee arthroplasty using mechanical, anatomical, kinematic, and functional limb axis alignment techniques. It also describes the principles and methods of planning and surgical technique. Results: From October 2023 to November 2025, 472 patients underwent robotic total knee arthroplasty at the Traumatology, Orthopedics, and Joint Pathology Clinic of Sechenov University Clinical Hospital No. 1. Conclusion: Total knee arthroplasty can be safely performed using any of the presented methods of limb alignment. However, restoring a patient's natural anatomy using traditional instruments can sometimes be challenging. Therefore, the use of robotic technologies with intraoperative visualization and implant positioning may be very promising, although they currently lack long-term benefits. This necessitates further research to identify the limitations of these methods and determine which patients will benefit most from which type of limb alignment and implant positioning.