Navigated anterior cruciate ligament reconstruction: radiographic validation of a nonimage-based system.

The authors compared the intraoperative navigated measurements of the location of the tibial and femoral tunnels during arthroscopic-assisted anterior cruciate ligament reconstruction to the postoperative measurements performed on standard plain radiographs in 56 patients. The position of the center of the tibial and femoral tunnels was measured intraoperatively with the OrthoPilot (B. Braun Aesculap, Tuttlingen, Germany) and postoperatively on plain anteroposterior and lateral radiographs. The center of the tibial tunnel was located at 43% of the mediolateral tibial dimension intraoperatively and at 41% of the mediolateral tibial dimension postoperatively (P=.14). The center of the tibial tunnel tibial was located at 40% of the anteroposterior tibial dimension intraoperatively and at 35% of the anteroposterior tibial dimension postoperatively (P=.01). The center of the femoral tunnel was located at 85% of the anteroposterior femoral dimension intraoperatively and at 76% of the anteroposterior femoral dimension postoperatively (P<.001). A significant correlation was found between intraoperative navigated and postoperative radiographic measurements only at the femur. Good agreement existed between all navigated and radiographic measurements. The OrthoPilot navigation system allows an accurate measurement of the location of the tibial and femoral tunnels during anterior cruciate ligament reconstruction.