Rupture of the anterior cruciate ligament (ACL) is one of the most frequent forms of knee sports injuries. Nowadays, ACL reconstruction is commonly performed to help patients restore their rotational stability. However, in patients with high risk factors, the risk of ACL reconstruction failure remains high, primarily because of continuous postoperative anterolateral rotational instability. This rotational instability after ACL reconstruction has prompted researchers to focus on the anterolateral complex of the knee, such as iliotibial tract and anterolateral ligament (ALL). Among them, ALL has remained largely unappreciated for more than a century since its discovery in 1879. Even though it is still controversial, most studies in recent years have supported the anterolateral ligament as an independent ligament and a crucial anatomical component for preserving the rotational stability of the knee joint. Although augmentation of the anterolateral complex has experienced twists and turns, the anatomic ALL reconstruction, which can be performed minimally invasively and has a low risk of complications and minimal injury, is reappearing as a key strategy to address this problem. Currently, the majority of scholars believe that the need for combined ALL reconstruction during ACL reconstruction should be taken into account when there is severe rotational instability present, such as high-grade pivot shift test preoperatively, ACL revision surgery, and high requirements for rotational stability, such as age less than 25 years and the need to participate in pivoting sports. The corresponding suggested criteria are also put forth in the authoritative consensus of both domestic and foreign sources. However, the surgical indications chosen by different experts based on their individual experiences are not all consistent. Due to conflicting reports on the actual impact of ALL reconstruction on improving rotational stability and whether it will excessively restrict knee's internal rotation function, there is still much debate among researchers regarding whether ALL reconstruction and ACL reconstruction should be combined. Currently, there are two main reconstruction techniques: ALL single bundle reconstruction and Y-construct ALL double bundle reconstruction. Y-construct ALL double bundle reconstruction has a better ability to restore the original anatomy and is recommended in the consensus, but there is still a lack of randomized controlled trials between the two techniques. Therefore, the combination of ALL reconstruction at the time of ACL reconstruction has been clinically started in recent years for patients who are susceptible to failure after ACL reconstruction, which also raises many controversies.

Anterior cruciate ligament injuries; Anterior cruciate ligament reconstruction; Rotation; Joint instability; Anterolateral ligament