ABSTRACT
The main function of anterior cruciate ligament (ACL) is to maintain stability of the knee joint and prevent anterior displacement of the tibial plateau. ACL injury accounts for more than 50% of the knee joint injuries. If not timely handled, it will increase the risk of secondary injuries to structures such as the meniscus and cartilage, causing chronic pain and degeneration of the knee joint. Although most ACL injuries can be determined by their direct signs on MRI, the identification of complex situations and partial tears of ACL are still not satisfactory, which subsequently affects treatment strategies. After ACL injury, changes in anatomical relationship of the knee joint can also lead to morphological changes in other structures such as the posterior cruciate ligament (PCL) on MRI, and these indirect signs can assist in the diagnosis of ACL injury. The authors reviewed the application of MRI-related indicators of PCL in diagnosing ACL injury, hoping to provide references and new ideas for clinical decision-making.