Related Experiment Video
Updated: Mar 1, 2026
Augmented Reality Navigation-Guided Core Decompression for Osteonecrosis of Femoral Head
Published on: April 12, 2022
Restricted kinematic alignment total knee arthroplasty using augmented reality technology to maintain limb alignment
Sachiyuki Tsukada1, Hiroyuki Ogawa2, Tsutomu Nakayama3
1Department of Orthopaedic Surgery, Hokusuikai Kinen Hospital, 3-2-1 Higashihara, Mito, Ibaraki, 310-0035, Japan.
Background:
An augmented reality (AR)-aided navigation system that utilizes a standard smartphone enables accurate alignment of femoral and tibial components in total knee arthroplasty (TKA) and provides real-time intraoperative quantification of joint gaps. This study aimed to integrate the AR-aided navigation system into the surgical technique of restricted kinematic alignment and to evaluate its clinical effectiveness.
Methods:
We compared 45 restricted kinematic alignment TKAs performed using posterior cruciate ligament (PCL) retaining medial-congruent prosthesis with an AR-aided navigation system and 40 mechanically aligned TKAs performed using PCL resecting posterior-stabilized prosthesis in patients with preoperative varus or neutral lower limb alignment. In the restricted kinematic alignment group, femoral and tibial alignments were determined using calipered and soft tissue-guided techniques, respectively, with the AR-aided navigation system providing real-time confirmation that angular values remained within safe boundaries. The target intraoperative extension gap was a rectangular configuration with equal medial and lateral widths.
Results:
Intraoperative measured value of the soft-tissue imbalance with the knee in extension was significantly smaller in the restricted kinematic alignment group than in the mechanical alignment group (1.1 ± 1.1° vs 2.5 ± 2.2°; 95% CI, 0.7 to 2.2°; P < 0.001; Cohen's d = 0.85). After propensity score matching, no significant differences were observed between the groups in either the timed up-and-go test or the 10-m walk test at 1 week postoperatively (12.6 ± 3.5 s vs 13.2 ± 5.3 s; 95% CI, - 3.0 to 1.7; P = 0.60; and 11.7 ± 2.5 s vs 11.9 ± 3.2 s; 95% CI, - 1.7 to 1.3; P = 0.82, respectively).
Conclusions:
Restricted kinematic alignment TKA using PCL retaining medial-congruent prosthesis achieved more balanced intraoperative soft-tissue tension than the mechanical alignment TKA using posterior-stabilized prosthesis. However, early postoperative walking speed did not differ between the two groups.
