1.Do you know meniscus? Meniscus: the fibrocartilage plate located between the femoral condyle and the tibial condyle. The role of the meniscus: (1) Deepens the concavity of the tibial condyle to accommodate the concavity of the femoral condyle and enhance joint stability. (2) In synergy with the cruciate ligament, it controls and guides the mild spiral movement of the knee joint. (3) Rich in elasticity, able to withstand gravity and absorb oscillations. Tianke, Department of Orthopedics, First Affiliated Hospital of Zhengzhou University (4) Disperses synovial fluid and lubricates the joint. (5)Nutrition: the meniscus is rich in blood flow around the periphery and can be repaired after injury; there is no blood vessel in the body, nutrition is supplied by joint fluid, and it is difficult to repair after injury. (6) Medial meniscus: C-shaped, combined with the deep fibers of the medial collateral ligament. Lateral meniscus: O-shaped, with large mobility. (7) Disc meniscus: easily damaged. More common in the lateral side. 2.How to cause meniscus injury (1)Grinding force: violent rotation of knee joint. (2) There are four factors that must be present to cause meniscus injury: Half flexion. Internal abduction and adduction. Gravitational compression. Rotation. (3) Typical history of medial meniscus injury: soccer players, coal miners. 8) Injury is likely to occur during rotational movements. 3, what are the symptoms of meniscus injury? (1)The patient shows symptoms:pain, joint effusion, interlocking, playing soft leg, joint popping sound. (2) The patient’s signs: quadriceps atrophy, joint swelling, joint gap pressure pain, hyperextension and hyperflexion pain. 4.How to treat meniscal injury The most effective treatment – arthroscopic treatment, for diagnosed meniscal injury, arthroscopic treatment and surgery should be performed as soon as possible, not only to give a clear diagnosis while repairing, but also to discover other combined injuries in the joint, such as cruciate ligament injury of the knee, articular cartilage injury, etc.