VELYS robotic-assisted solution achieves more accurate bone cutting and neutral ground mechanical axis compared with an accelerometer-based portable navigation system in ground kinematically aligned total knee arthroplasty.

PURPOSE: This study aimed to compare the accuracy of bone cutting, achievement of target alignment, and early clinical outcomes between ground kinematically aligned total knee arthroplasty (KA-TKA) performed using the VELYSTM robotic-assisted solution (VRAS) and that performed using an accelerometer-based portable navigation system (APNS) in patients with varus osteoarthritis. METHODS: This cohort study prospectively enrolled 35 consecutive patients who underwent ground KA-TKA using the VRAS and compared them with 35 consecutive patients treated with the same surgical procedure using the APNS. The primary end point was the accuracy of bone cutting and achievement of target alignment. Clinical outcomes were evaluated at 1 year postoperatively. RESULTS: The VRAS group demonstrated significantly smaller mean absolute errors from target values, particularly in femoral bone cutting and achievement of a neutral ground mechanical axis, compared with the APNS group (0.7 ± 0.8° versus 1.5 ± 1.1°, 1.6 ± 1.8% versus 3.0 ± 2.4%, p < 0.05, respectively). There were no significant differences in range of motion and 2011 Knee Society Score between groups. CONCLUSIONS: Ground KA-TKA performed using the VRAS achieved higher accuracy in bone cutting and more reliable achievement of a neutral ground mechanical axis, compared with the APNS.