Recently, the existing knowledge of ACL anatomy was enhanced by a landmark anatomical study. Nevertheless, in a recent study, Kondo et al found that the influence and reciprocal relationship of an insulated AM or PL bundle tear might have been overestimated.

The PL bundle has been shown to have particular stabilizing effects on the anteroposterior and rotational forces in near-to-extension positions of less than 30Р’В°, whereas the AM bundle becomes tensioned and functional at higher flexion angles. The oval/flat structure of the ACL plays an important role in stabilizing the knee joint under different flexion angles and, therefore, compensating for shifting knee flexion axes. Due to the oval shape of the femoral condyles, the position of the joint axis varies during flexion in the sagittal plane. The anatomy of the ACL and functional bundles has been biomechanically evaluated in many studies, and surgical techniques have evolved as a result. The tibial insertion of the AM bundle is located close to the anterior horn of the lateral meniscus at approximately the first 30% mark of a virtual sagittal line crossing the tibial plateau, while the PL bundle inserts slightly posterolateral to the AM bundle at approximately 44% of the virtual sagittal line. The femoral insertion of the PL bundle is located at anterior of the AM bundle, also bordering the edge of the chondral bone. The AM bundle is inserted deep in the intercondylar notch directly in front of the intercondylar line and the edge of the chondral bone. The femoral origin was described as oval shaped with a longitudinal diameter of 18 mm and a width of approximately 11 mm. These two bundles have been associated with different roles in anteroposterior and complex-rotational stabilization of the joint. The structure of the ACL has been described as two functional bundles: The anteromedial (AM) and the posterolateral (PL) bundle. The ACL has its origin at the medial area of the lateral femoral condyle and inserts into the center of the eminentia of the tibia plateau next to the anterior horn of the lateral meniscus. Surgical treatment of the ACL in the context of other injured structures and reconstruction of the intact joint kinematics are suggested to be the keys to a good clinical outcome. Persistent instability of the knee may be associated with long-term degenerative lesions. In addition, compression of the lateral condyle with a bone bruise or chondral lesion is often associated with the injury due to the valgus trauma. Therefore, ACL injuries are often associated with other ligamentous injuries, such as a (partial) rupture of the medial collateral ligament (MCL) or the menisci. An acute ACL rupture is a common orthopedic trauma, with an estimated incidence of 00 persons and a mean age of 32 years in Sweden and an estimated incidence of up to 00 persons in the United States.Р”Р„ common and frequent injury mechanism is non-contact combined valgus- and internal-rotation trauma. The main functional role of the ACL is to provide stability against anterior tibial translation (ATT) and internal rotation. The ACL is a central ligament of the knee. Its stability and motion are basically controlled by ligaments such as the anterior cruciate ligament (ACL). An angle of >15Р’С” indicates an abnormal course and probable anterior cruciate ligament tear 3.Biomechanics is one major key to the function, stability and aging process of joints. The angle is calculated at the intersection of these two lines. It is calculated by drawing a line parallel to the roof of the intercondylar notch of the femurР’В ( Blumensaat line)Р’В and one parallel to the distal portion of the anterior cruciate ligament. The ACL Blumensaat line angle is normally РІвЂ°В¤15Р’С”. Unlike other ligaments or tendons, the anterior cruciate ligament normally has a heterogeneous appearance and the anteromedial and posterolateral bundles are defined by surrounding high-intensity structures 1. The ACL functions to prevent posterior translation of the femur on the tibia (or anterior displacement of the tibia) during flexion-extension of the knee.Р’В The anteromedial bundle is responsible for the posterior translation of the femur at 30 degrees flexion, and the posterolateral bundle resists hyperextension and prevents posterior translation of the femur in extension 1, 2.

attaches to the wall of the intercondylar notch.

more vertically oriented, and slightly shorter.

attaches to the roof of the intercondylar notch.

Like the posterior cruciate ligament, the ACL is intracapsular but extrasynovial. The anterior cruciate ligament arises from the anteromedial aspect of the intercondylar area on the tibial plateau and passes upwards and backwards to attach to the posteromedial aspect of the lateral femoral condyle.

Acl anatomy