The meniscus is a fibrocartilage located in the knee joint, so named because of its half-moon shape. It is located between the joint surface formed by the tibia and the femur, increasing the contact area between the femoral condyle and the tibial plateau, thus increasing the stability of the knee joint. The meniscus is divided into an anterior horn, a body part and a posterior horn. Its function is to stabilize the knee joint and transmit the knee loading forces. It is the stabilizing effect of the meniscus that ensures that the knee joint is protected from injury over years of weight-bearing exercise. Injury to the meniscus is mainly caused by indirect violence. Simply put, if there is a twisting inversion and outversion of the knee during knee flexion and extension, there will be contradictory movements of the meniscus itself, leading to injury. Meniscal injuries are determined by the patient’s symptoms, physical findings and imaging. After the injury occurs, the patient mostly shows pain in the joint space, a popping sound, or even limited knee movement due to joint interlocking, and a sudden inability to straighten or squat. Physician examination can find obvious joint space pressure pain, prominent, characteristic examination including McKay’s test, grinding test, etc. For some patients whose symptoms and physical examination are not clear, the most common test is MRI of the knee joint, which has a relatively high positive diagnostic rate.