The meniscus is the cartilage between the femoral condyles and the tibial plateau in the knee joint. It mainly serves to absorb shock, reduce vibration, transmit stress, promote synovial lubrication, increase joint stability, increase the role of the chain belt conduction, increase joint matching and protect the articular cartilage. In flexion and extension, the meniscus is closely related to the tibial plateau and is also affected by the movement of the femoral condyles, so it produces “contradictory movements”, which is the main reason why the meniscus of the knee is prone to injury. The main symptoms of meniscus injury include knee pain, joint effusion, a ringing sound during knee flexion and extension activities, a feeling of joint locking (the joint is stuck), and even a limitation of flexion and extension. To determine whether there is a meniscal injury, a physical examination by a specialist and MRI findings are required. For those with severe symptoms, significant swelling and pain, recurrent strangulation, frequent obstruction to daily life and work, and athletes obstructing sports training, arthroscopic knee surgery should be considered. Depending on the injury, meniscal suturing or partial or total meniscectomy may be used. However, whichever treatment option is used, the meniscus should be preserved as much as possible, trimmed or sutured as much as possible, or preserved as much as possible while maintaining the stability of the residual meniscus to minimize biomechanical changes. However, if a severely damaged meniscus is not treated with surgery as early as possible, the damaged meniscus will wear away the articular cartilage, which in turn will cause degeneration of the joint. It is like a bearing with a broken ball inside, and everyone should know what to do with it.