Anatomic study of the double-bundle of the anterior cruciate ligament with the knee in 90º flexion.

OBJECTIVE To anatomically evaluate the femoral origin and tibial insertion of the anteromedial and posterolateral bands of the anterior cruciate ligament. METHODS We studied eight cadaver knees as for the following: in the femur, distance from the center of the anteromedial band to the deep cartilage and the ceiling; also in the femur, distance from the center of the posterolateral band to the deep cartilage, to the inferior cartilage and to the superficial cartilage. In the tibia, we measured the distances between the anterior tibial bone edge to the anterior region of the anteromedial band, to the center of the anteromedial band and to the center of the posterolateral band. We also measured the distance between the center of the posterolateral band to the tibial posterolateral bone and the total length of the anteroposterior tibial insertion of the anterior cruciate ligament. RESULTS In the femur, the distance from the center of the anteromedial band to the deep cartilage was 6.3 ± 1.4 mm, and 11.2 ± 2 mm to the ceiling. Also in the femur, the distance from the center of the posterolateral band to the deep cartilage was 9 ± 4 mm, to the superficial cartilage 7.6 ± 1.8 mm, and to the inferior cartilage 4.2 ± 0.9 mm. In the tibia, the distance from the anterior tibial bone edge to the anterior region of the anteromedial band was 11.9 ± 2.8 mm, to the center of the anteromedial band 18.8 ± 2.6 mm, and to the center of the posterolateral band 26.5 ± 2.3 mm. The distance from the center of the posterolateral band to the tibial posterior bone edge was 19.6 ± 4 mm and the total length of the anteroposterior tibial insertion of the anterior cruciate ligament was 19.4 ± 1.8 mm. CONCLUSION The center of the tibial insertion of the anteromedial band is approximately 20mm distant from the anterior edge of the tibia, while the center of the posterolateral band is approximately 30 mm. The distance between the center of the origin of the anteromedial band to the deep cartilage is 6mm, and to the posterior lateral 10mm.