Navigation in total knee arthroplasty. A multicenter study

We carried out a multicentre study to compare the postoperative femorotibial radiographic axis in two total knee replacement groups; one using manual instrumentation and the other using navigation. In the latter group, three navigation systems were used: Stryker, Orthopilot and Navitrack. The prior circumstances of patients in terms of age, weight, aetiology, epicondylar perimeter, patellar tendon length and knee deformity was similar in both groups. The duration of the operation was longer in the group with navigation (16.7 min). A normal femorotibial axis was more frequently obtained in the group with a navigator compared to the manual group (48.1% and 30%, respectively). A varus axis was most common in the manual group (42.2 and 26.9%, respectively). When we analysed the final postoperative radiographic axis, taking 180 degrees to be a normal result, we noted that cases where manual instrumentation was used deviated by 1.19 degrees more than those carried out with navigation, with this difference being statistically significant (P<0.001). No significant differences were found in the final angle of the extremity with the different navigation systems. The navigation systems used in this study improve the frontal angle of the arthroplasty.