Initial Experience with the NAVIO Robotic-Assisted Total Knee Replacement-Coronal Alignment Accuracy and the Learning Curve

J Knee Surg. 2022 Oct;35(12):1295-1300. doi: 10.1055/s-0040-1722693. Epub 2021 Jan 28.


One of the primary aim of total knee arthroplasty (TKA) is restoration of the mechanical axis of the lower limb. Maintenance of the mechanical axis within 3 degrees of neutral has been shown to result in improved clinical results and implant longevity. The aim of this study was to investigate the efficacy of this robotic-assisted system in coronal plane component positioning in TKA. We also describe the learning curve associated with adoption of this technology. A total of 72 total knee replacements were completed between November 2017 and September 2018 by a single surgeon using the robotic-assisted surgery (RAS) system. Cases were recorded from the time the study surgeon first adopted this technology and represent the "learning curve." Pre- and postoperative coronal weight-bearing alignments were measured and intraoperative robotic-assisted registration data and duration of use were collected. Of the 72 TKAs in this series, 93.3% were corrected to the desired alignment of within 3 degrees of neutral. The knees that were not corrected to neutral had a mean preoperative alignment of 11.57 degrees of deformity as compared with 4.29 degrees for those that were corrected to neutral. A learning curve effect during adoption of this new technology was not found when analyzing RAS usage time. The RAS system produced accurate coronal alignment in TKA in more than 93% of cases with no learning curve effect. Our study suggests that this system is easily adopted, safe, and accurate.

MeSH terms

  • Arthroplasty, Replacement, Knee* / methods
  • Humans
  • Knee Joint / surgery
  • Knee Prosthesis*
  • Learning Curve
  • Osteoarthritis, Knee* / surgery
  • Robotic Surgical Procedures*