The knee joint is composed of the inner and outer condyles of the lower end of the femur, the platform of the upper end of the tibia and the patella in the front, and there is a cartilage “spacer” between the femur and the tibia articular surfaces, i.e., meniscus, and the medial meniscus is in the shape of “D”, with a thicker outer edge and a thinner immortal edge. The lateral meniscus is “C” shaped with a slightly smaller inner edge. The role of the meniscus is to reduce friction and vibration. So that the pressure is evenly distributed, cushioning pressure, etc., because the meniscus is located between the femur and tibia, easier to cause injury. When the lower limb weight bearing, in the foot fixed, the knee slightly flexed position, the joint suddenly internal rotation, knee extension or external rotation, knee extension, that may cause meniscus tear injury. Daily work life, picking, lifting heavy objects, or riding a bicycle in a hurry to get off the unsteady stand; or in the fierce soccer, basketball and other sports, athletes scramble, may occur meniscus injury. Long-term squatting or semi-squatting work, such as automobile mechanics, repeated squatting and standing, meniscus wear and tear is serious, will also be injured. Such patients are mostly young adults. According to statistical research, meniscus injury “Chinese and foreign differences”: Europeans and Americans are prone to injuries to the medial meniscus, while the Chinese to the lateral side of the common. In acute injuries, some people can hear the sound of popping in the joint. Often accompanied by synovial membrane damage to the inner wall of the joint capsule, causing intra-articular hemorrhage and fluid leakage. After the injury, the joint gradually swells and continues to hurt. After rest and general anti-swelling and anti-pain treatment, the symptoms are reduced, but the joint space is still painful, especially when the joint is extended and flexed to a certain position. Walking, especially up and down the stairs, feel the weakness of the lower limbs, often playing soft legs, affecting work and life. Over time, the thigh muscles atrophy and the circumference becomes thin. Some patients walk, suddenly feel abnormal knee pain, can not move, and even fall. After enduring the pain and moving the calf, they can resume walking again. This symptom is called joint interlocking, which is caused by the damaged meniscus stuck in the joint. In some patients, the knee joint feels bouncing when moving and a popping sound is heard. A common diagnostic method used in the past was knee arthrography. Because the meniscus is a cartilaginous structure that does not show up on conventional X-rays, a non-toxic contrast agent or gas can be injected into the joint to fill the space beyond the meniscus, so that the meniscus shows up to see if there are any signs of damage. With advances in imaging technology, the option of magnetic resonance MRI, which does not require the use of contrast and is painless, is the most commonly used diagnostic method today. Alternatively, arthroscopy can be performed under anesthesia, where a delicate and dexterous arthroscope is placed into the joint through a very small incision, and through the use of fiber optic fibers, the lesions of meniscus damage can be seen directly from the outside, and the meniscus can also be repaired and removed with attached fine instruments. In addition, ultrasonography can assist in the diagnosis. The meniscus only has a blood supply in the outer portion near the synovium; most of it is bloodless tissue that relies on joint fluid to maintain metabolism. Due to the relative lack of nutrients, it is difficult for an injury to heal on its own once it occurs. Taking medication, injections, plasters or physical therapy can only provide temporary relief of symptoms without a radical cure. Over time, it will lead to traumatic arthritis, and the symptoms will become more serious. Therefore, meniscus injuries should be taken seriously and surgical treatment should be considered. Surgical treatment of meniscus injury, the current more mature way is arthroscopic minimally invasive surgery, small damage, fast recovery. By removing part of the damaged meniscus, knee symptoms can be eliminated or significantly reduced. Long-term follow-up of patients after meniscectomy has shown that it can still lead to early degeneration of the joint. With advances in surgical techniques and instrumentation, arthroscopic meniscal suturing can now be considered for most meniscal injuries, and healing rates of about 80% can be achieved. In order to promote recovery, before and after meniscus surgery, the quadriceps muscle function exercise should be carried out diligently. The method is, the patient lying flat on the bed, straighten the lower limbs, force the kneecap (patella) upward, and then relax, repeated force. Or straighten the lower limbs to lift, put down, repeated. To a certain extent, you can also hang a certain weight of sandbags on the neck of the foot to practice. After exercise, the quadriceps muscle is strong and powerful, which is conducive to maintaining joint stability. Exercise should start before the operation, and continue the day after the operation. At this time, the wound is still painful, the patient often have concerns, such as the fear of wound cracking, inside bleeding and so on. It is important to eliminate these concerns and exercise through the pain. After simple meniscectomy, patients can go down to the ground at an early stage to bear weight and gradually increase the range of motion of the joints. The degree of exercise has a clear relationship with the recovery effect, the better the exercise, the more effect. After meniscus suture surgery, patients generally need to brake for about 4 weeks, favorable meniscus healing.