Knee joint in the human body, is a stable joint, the main movement surface in the sagittal plane, the main function is flexion and extension, the meniscus is located between the femur and tibia, its existence can increase the contact surface of the bone, better in the displacement to spread the pressure borne by the bone; the second is that it increases the degree of concavity of the joint surface, as the cushioning plate has the best fixation ability. It is also because of the great cushioning effect of the meniscus, so in the various movements of the knee joint, the meniscus is also under immense pressure, very easy to damage. Here we talk about the role of the meniscus of the knee and common injuries. 1, meniscus is the knee joint inside the 2 crescent-shaped cushion, in the rigid femur and tibia between, can increase the stability of the knee joint, cushion shock, reduce knee wear, its essence is 2 pieces of fibrous cartilage. 2, meniscus tear mainly manifested as knee pain, flexion and extension activities are limited, playing soft legs, joint interlock (flexion and extension activities suddenly appear joint lock can not move, need to be massaged for several minutes before you can continue activities). Because the meniscus is a soft cushion between the femur and tibia, when it receives pressure from the femur and tibia, especially rotational pressure, it is prone to injury/tear, and common injuries include playing soccer with a strong shot. 3. For adult meniscus, only 1/3 of the peripheral area has blood vessels (called red zone), which means that the blood supply to the meniscus is very poor. Once an injury occurs, especially in the white zone which is completely devoid of blood vessels or the red-white zone which is partially vascularized, it is extremely difficult to heal on its own, and the effect of conservative treatments is very poor.