Validation of the position of the femoral tunnels in anatomic double-bundle ACL reconstruction with 3-D CT scan

Abstract

This study compares the positioning of femoral AM and PL tunnels obtained with specific ancillary instruments during anatomic double-bundle ACL reconstruction with the native ACL footprint using three-dimensional computed tomography (3-D CT). In 35 consecutive patients, anatomic double-bundle ACL reconstruction was performed with specific ancillary instruments. Three-dimensional CT reconstruction of both knees was performed using the volume rendering technique. In the controls (contralateral knee, with intact ACL), the angle between the longitudinal axis of the footprint and the axis of the femur, the "footprint angle" (FA) was measured. On the involved side, using the axis passing through the tunnel centers, FA was also measured. In both the groups, footprint's length and width, and distances to cartilage margins were measured. FA was 28.1 degrees +/- 5.0 degrees in the controls and 32.9 degrees +/- 15.8 degrees on the involved side (n.s.). There was no statistical difference between the two groups for the other morphometric parameters: footprint's length and width, and distances to cartilage margins. Using specific ancillary instruments the morphometric parameters of the reconstructed femoral ACL footprint were similar to the native ACL.