Improved alignment accuracy but similar early clinical outcomes with NAVIO imageless robotic-assisted vs. conventional total knee arthroplasty: a meta-analysis

BACKGROUND: This meta-analysis aimed to compare the radiological and clinical outcomes in patients who underwent total knee arthroplasty (TKA) using either NAVIO-assisted TKA or conventional TKA. METHODS: In accordance with the Preferred Reporting Items for Systematic Reviews and meta-analysis criteria, a systematic review was carried out. We looked through the databases of PubMed, Web of Science, Cochrane Library, Embase, Scopus, ClinicalTrials.gov, China National Knowledge Infrastructure (CNKI), Wanfang, China Biology Medicine Disc (CBM), and China Science and Technology Journal (CSTD) databases in April 2025 to identify studies involving NAVIO-assisted TKA versus conventional TKA. RESULTS: We identified 2483 TKAs assessed in 21 studies. There were no significant differences in terms of Visual Analogue Scale(VAS, P = 0.38), Knee Society Score (KSS, P = 0.68), KSS function(KSSF, P = 0.96), Forgotten Joint Score-12 (FJS-12, P = 0.73), Extension range of motion (EROM, P = 0.12), Flexion range of motion,(FROM, P = 0.28), Hip-knee-ankle angle(HKA, P = 0.66),Frontal femoral component angle (FFC, P = 0.22), Frontal tibial component angle (FTC, P = 0.18), Femoral rotation angle(FRA, P = 0.17), Medial tibial plateau angle(MPTA, P = 0.34), Lateral femoral component angle (LFC, P = 0.65), Lateral tibial component angle (LTC, P = 0.47), Change in joint line height(CJLH, P = 0.06), outlier of PTS(P = 0.18), Hospital stays (P = 0.07) and Complication rate(P = 0.32), However, in comparison to conventional TKA, NAVIO-assisted TKA was observed with less outlier of HKA (P = 0.00), less outlier of FFC (P = 0.05), less outlier of FTC (P = 0.04), less lateral distal femur angle (LDFA, P = 0.04), less posterior slope of the tibial component (PTS, P = 0.011), less decrease in Hb (P = 0.02) and longer operation time (P = 0.02). CONCLUSION: This meta-analysis, specifically focused on the NAVIO system, suggests that NAVIO-assisted TKA is associated with improved accuracy in achieving target mechanical and anatomical alignment compared to traditional TKA. Nonetheless, the two groups demonstrated similar complication rates and short-to-intermediate-term clinical and functional results in this analysis. A statistically significant, though modest, benefit in terms of reduced blood loss was observed for the NAVIO group. Further adequately powered and rigorously designed long-term follow-up studies are essential to determine whether the observed improvements in radiological alignment accuracy translate into significant long-term clinical benefits."