Anterior cruciate ligament bundle insertions vary between ACL-rupture and non-injured knees

Purpose The present study aimed to investigate the three-dimensional topographic anatomy of the anterior cruciate ligament (ACL) bundle attachment in both ACL-rupture and ACL-intact patients who suffered a noncontact knee injury and identify potential differences. Methods Magnetic resonance images of 90 ACL-rupture knees and 90 matched ACL-intact knees, who suffered a noncontact knee injury, were used to create 3D ACL insertion models. Results In the ACL-rupture knees, the femoral origin of the anteromedial (AM) bundle was 24.5 +/- 9.0% posterior and 45.5 +/- 10.5% proximal to the flexion-extension axis (FEA), whereas the posterolateral (PL) bundle origin was 35.5 +/- 12.5% posterior and 22.4 +/- 10.3% distal to the FEA. In ACL-rupture knees, the tibial insertion of the AM-bundle was 34.3 +/- 4.6% of the tibial plateau depth and 50.7 +/- 3.5% of the tibial plateau width, whereas the PL-bundle insertion was 47.5 +/- 4.1% of the tibial plateau depth and 56.9 +/- 3.4% of the tibial plateau width. In ACL-intact knees, the origin of the AM-bundle was 17.5 +/- 9.1% posterior (p < 0.01) and 42.3 +/- 10.5% proximal (n.s.) to the FEA, whereas the PL-bundle origin was 32.1 +/- 11.1% posterior (n.s.) and 16.3 +/- 9.4% distal (p < 0.01) to the FEA. In ACL-intact knees, the insertion of the AM-bundle was 34.4 +/- 6.6% of the tibial plateau depth (n.s.) and 48.1 +/- 4.6% of the tibial plateau width (n.s.), whereas the PL-bundle insertion was 42.7 +/- 5.4% of the tibial plateau depth (p < 0.01) and 57.1 +/- 4.8% of the tibial plateau width (n.s.). Conclusion The current study revealed variations in the three-dimensional topographic anatomy of the native ACL between ACL-rupture and ACL-intact knees, which might help surgeons who perform anatomical double-bundle reconstruction surgery.