Surgical and biomechanical concepts of anatomic anterior cruciate ligament reconstruction

The purposes of this review are to explain surgical and biomechanical concepts of anatomic anatomic anterior cruciate ligament (ACL) reconstruction and to introduce our anatomic reconstruction procedure of the anteromedial (AM) and posterolateral (PL) bundles of the ACL using hamstring tendon autografts. According to common medical concept, anatomical ACL reconstruction is defined as the reconstruction in which all 4 ends of 2 tendon grafts are grafted at the center of the anatomical attachment of the AM bundles or the PL bundles, not only on the femur but also on the tibia, because only such a procedure allows for the reconstruction of 2 bundles having an anatomical orientation. On the basis of our anatomic studies on the normal attachments of the ACL, we developed an arthroscopy-assisted anatomic reconstruction procedure of the AM and PL bundles that involves a new method of creating the tibial and femoral tunnels for the posterolateral bundle. To insert a Kirschner wire as a guide into the tibia, we use an originally developed a Wire-navigator, which is a key device for the trans-tibial tunnel technique. To visualize the femoral attachment of the posterolateral bundle, the medial infra-patellar portal is more useful than the lateral one. Biomechanical studies have shown that anatomic double-bundle ACL reconstruction has some biomechanical advantages over a single-bundle reconstruction. In our clinical experience, results of the anatomic reconstruction were superior to those of the one-bundle reconstruction. We believe that the anatomic reconstruction of the AM and PL bundles using hamstring tendon autografts is clinically practical in the treatment for the ACL-deficient knee.