Method for Positioning the Tibial Tunnel in Anterior Cruciate Ligament Reconstructions

ABSTRACT

PURPOSE: This study determined that knee extension and its relationship to the slope of the intercondylar roof for positioning the tibial tunnel in ACL reconstructions. MATERIALS AND METHODS: Fifty subjects (25 men and 25 women) between the age of 25 and 40 were recruited for the study. We obtain a lateral roentgenogram of their knees in maximum extension. We measured knee extension angle, roof angle and the location of central axis of the tibial tunnel. We also used statview IV program for statistics. RESULTS: Regression analysis of the measurements from the two authors revealed knee extension (r2=0.846, p<0.0001), roof angle were reliably measured(r2=0.630, p<0.0001). There was a strong relationship between the two authors in their selection of the position for the center of the tibial tunnel(r2=0.702, p<0.0001). There was considerable variety in the degree of knee extension, roof angle and the position of the tibial tunnel. We failed to detect a difference between men and women since the population was insufficient. A correlation between knee extension and roof angle was week (r2=0.207, p<0.008). CONCLUSION: There is variety of extension angle and roof angle of knees among persons. It is required to customize the position of tibial tunnel in ACL reconstructions because of differences in anatomy.