Precision of tunnel positioning in navigated anterior cruciate ligament reconstruction.

PURPOSE

The aim of this study was to validate the precision of navigated tunnel positioning using a fluoroscopy-based computer-assisted technique.

METHODS

Ten human cadaveric knees were operated on under operating room conditions. After resection of the anterior cruciate ligament, referenced fluoroscopic images were acquired to plan the tunnel positions according to established radiologic measurement methods. Afterward, femoral and tibial K-wires were placed by use of navigated drill guides without arthroscopic control. Deviations between the planned and actually drilled tunnel positions at the joint level were analyzed by use of both navigated and radiologic assessment methods.

RESULTS

Navigated analysis between planned and actually drilled tunnel position showed mean deviations of 0.4 mm (range, 0 to 1 mm; SD, 0.52 mm) at the femur and 0.5 mm (range, 0 to 1 mm; SD, 0.5 mm) at the tibia. The radiologic analysis showed mean deviations for the femoral tunnel of 0.83 mm for the depth (range, 0 to 1.46 mm; SD, 0.46 mm) and 0.54 mm for the height (range, 0 to 1.08 mm; SD, 0.41 mm). At the tibia, deviation of 0.74 mm (range, 0 to 1.2 mm; SD, 0.46 mm) was found.

CONCLUSIONS

The fluoroscopy-based navigation system used in this study allows for precise tunnel positioning with deviations of 1 mm or less.

CLINICAL RELEVANCE

This technique provides accurate tunnel placement in anterior cruciate ligament surgery.