Evaluation of the accuracy of three CT-free surgical navigation systems in total knee arthroplasty (TKA) using a coordinate measuring machine.

Previous studies have shown that the accuracy of computer-assisted surgery (CAS) via computed tomography (CT) free systems is useful when applied in the clinical realm. However, few studies have compared CAS systems to the current gold standard, manually applied measuring guides. Thirty total knee arthroplasties (TKA) were performed on artificial Sawbones knees using three different navigational systems. The TKAs were performed by a fellowship-trained joint reconstruction surgeon as well as a third- and a fourth-year orthopedic resident to assess differences in performance with regard to surgical experience. Using a two-way multivariate analysis of variance (MANOVA), no statistical differences were found in the accuracy of each of the three CAS navigational systems. Similarly, no differences were found between the accuracy of CAS systems and the gold standard measuring method. No differences in performance were found between the orthopedic residents and the fellowship-trained surgeon, suggesting a relatively small learning curve and usability. Definitive assessment of the clinical efficacy should be further assessed in a cadaveric study or, ideally, by way of a randomized clinical trial.