Computed tomography is not necessary to assess rotation of the femoral component in navigation-assisted total knee replacement.

Objective: To demonstrate that postoperative computed tomography (CT) is not needed if navigation is used to determine the rotational position of the femoral component during total knee replacement (TKR). Methods: Preoperative CT, navigational, and postoperative CT data of 70 TKR procedures were analysed. The correlation between the rotational angulation of the femur measured by CT and that measured by perioperative navigation was examined. The correlation between the femoral component rotation determined by navigation and that determined by CT was also assessed. Results: The mean femoral rotation determined by navigation was 2.64 degrees +/- 4.34 degrees, while that shown by CT was 6.43 degrees +/- 1.65 degrees. Postoperative rotation of the femoral component shown by CT was 3.09 degrees +/- 2.71 degrees, which was closely correlated with the angle obtained through the intraoperative transepicondylar axis by navigation (Pearson's R = 0.930). Conclusions: Navigation can be used to collect the preoperative, intraoperative, and postoperative data and final position of the TKR. The rotation of the femoral component can be determined using navigation without the need for CT.