Comparison of Coronal Prosthetic Alignment After Total Knee Arthroplasty Using 3 Computer-Assisted Navigation Systems

Recent advances in surgical tools such as navigation systems have contributed to accurate implantation in total knee arthroplasty. Although several navigation systems have been developed, reports regarding which navigation system has better accuracy are few. Therefore, this study aimed to compare the accuracy of postoperative coronal alignment among 3 navigation systems. A total of 90 knee prostheses were implanted for 90 patients with osteoarthritis. Thirty patients were enrolled in each of the following 3 navigation groups: Stryker Navigation System II (computed tomography-free navigation; Stryker, Mahwah, New Jersey); OrthoPilot version 4.2 navigation system (computed tomography-free navigation; B. Braun Aesculap, Tuttlingen, Germany); and VectorVision navigation system (computed tomography-based navigation system; BrainLAB, Munich, Germany). Thirty consecutive total knee arthroplasties performed via the conventional method without navigation were selected as a control group for comparison with the navigation groups. Postoperative coronal mechanical axis and femoral and tibial coronal component angles were compared among the groups using long-leg standing radiographs for the rate of outliers beyond 3°. No differences were observed in the mean femoral and tibial component angles among the navigation and conventional groups. However, the proportion of outliers beyond 3° was higher in the conventional group than in the 3 navigation groups. No significant differences in the outlying values were found among the 3 navigation groups. These 3 navigation systems achieved equally accurate coronal mechanical alignment with fewer outliers. The navigation systems exhibited more precise implantation than the conventional method. [Orthopedics. 2018; 41(5):e621-e628.].