Accuracy of a New Augmented Reality Assisted Technique for Total Knee Arthroplasty: An In Vivo Study.

Background: Total knee arthroplasty (TKA) remains the standard of care for treating end-stage osteoarthritis of the knee. Approximately 15%-20% of the patients are dissatisfied following surgery. To improve accuracy and outcomes of TKA, various assistive technologies have been introduced. For this study, an augmented reality (AR) system was explored and tested. Methods: The Knee + system (Pixee Medical, Besancon, France) was used to guide TKA. It uses a combination of quick response-code labeled instruments and AR glasses to guide tibial and femoral cuts. The primary research goal was to evaluate its accuracy by direct comparing the planned angular values for lateral distal femoral angle, medial proximal tibial angle, hip-knee-ankle axis, and tibial slope to the intraoperative obtained values and the measured angles on postoperative full leg radiographs. The secondary research goal was to assess its feasibility. Results: This retrospective study evaluated 124 patients, with a follow-up of at least 1 year. The average absolute difference between planned and measured postop values were 1.39° for lateral distal femoral angle, 1.03° for medial proximal tibial angle, 2.16° for tibial slope, and 1.51° for hip-knee-ankle axis. Within the follow-up period, 8 complications were observed. The average surgical time was 83 minutes. Conclusions: This study has demonstrated a high accuracy, comparable to robotic-assisted total knee arthroplasty, of the Knee + AR system. It has shown to be a safe, cheap and time-efficient assistive technology for patients undergoing medial pivot TKA.