2025 ISAKOS Biennial Congress ePoster
Integrating Elongation Patterns with AR-Based Navigation in Kinematic Alignment TKA.
Atsushi Sato, MD, PhD, Yokohama, Kanagawa JAPAN
Marika Mukunoki, MD, Yokohama, Kanagawa JAPAN
Masataka Ota, MD, Tokyo JAPAN
Misako Takizawa, MD, Yokohama, Kanagawa JAPAN
Kanako Izukashi, MD, Yokohama, Kanagawa JAPAN
Jun Oike, MD, PhD, Koto, Tokyo JAPAN
Takayuki Okumo, MD, PhD, Tokyo, Tokyo JAPAN
Takayuki Koya, MD, PhD, Tokyo JAPAN
Koji Kanzaki, Prof., Yokohama JAPAN
Showa University Fujigaoka Hospital, Yokohama, Kanagawa, JAPAN
FDA Status Cleared
Summary
AR-based navigation, using AR glasses, enhances surgical precision and soft tissue balance by providing real-time information to the surgeon, aiding in the determination of the optimal implant position and limb axis. It may also provide new insights into MCL/LCL elongation for appropriate soft tissue balancing in TKA.
ePosters will be available shortly before Congress
Abstract
Introduction
In recent years, there has been a growing use of virtual reality (VR) and augmented reality (AR), which superimposes virtual space onto the real world, in the medical field. Particularly, due to limited reports on navigation for total knee arthroplasty (TKA) using AR, we will report our experience with AR-based navigation for TKA using AR glasses. The elongation pattern of the MCL/LCL is not well understood in normal knees, and even less so in the context of TKA. We also introduce the kinematic alignment method considering elongation patterns measured with this AR navigation system.
Methods
The subjects were 33 patients (40 knees) who underwent AR-based navigation TKA at our facility, with an average age of 78.4 years and an average BMI of 25.9 kg/m. The system used was NEXTAR (Medacta), in which each device is connected via Bluetooth, and the cameras for the femur and tibia are connected via infrared. The elongation, or the distance of ligament attachment (MCL/LCL), can be measured throughout the entire range of motion in the system.
Results
With this system, there were no complications such as neurovascular injury or pin site fractures. In this study, the preoperative HKA of 172.6° changed to 179.2° postoperatively. The final tibial varus angle was 3.4°, and the tibial posterior slope was 5.3°. The elongation pattern of the MCL remained nearly constant from extension to flexion. The LCL elongation pattern tended to shorten from extension to flexion, but it varied among individuals.
Discussion And Conclusion
AR has recently attracted attention for its potential to enhance accuracy in orthopedic surgery. While not yet widely used in the field, AR has demonstrated its ability to save time, reduce risks, and improve surgical precision. This technology, using AR glasses, enhances surgical precision and soft tissue balance by providing real-time information to the surgeon, aiding in the determination of the optimal implant position and limb axis. It may also provide new insights into MCL/LCL elongation for appropriate soft tissue balancing in TKA. In conclusion, this study demonstrated the safe use of AR-based navigation for TKA. Elongation may be an important factor in TKA. More clinical research data are necessary to validate the system's performance and assess its impact on clinical outcomes.