The meniscus is 2 crescent-shaped fibrocartilages that lie on the medial and lateral articular surfaces of the tibial plateau. Its cross-section is triangular in shape, thick on the outside and thin on the inside, slightly concave on top so as to fit the femoral condyles and flat on the bottom, where it meets the tibial plateau. Such a structure precisely allows the femoral condyles to form a deeper depression in the tibial plateau, thus increasing the stability of the spherical femoral condyles to the tibial plateau. The anterior and posterior ends of the meniscus attach to the middle non-articular surface of the tibial plateau, anterior and posterior to the intercondylar spine, respectively. This area can also be referred to as the anterior and posterior angles of the meniscus. In terms of the shape and location of the meniscus, the function of the meniscus is to stabilize the knee joint, transmit load forces to the knee joint, and promote intra-articular nutrition in the meniscal position. It is the stabilizing effect of the meniscus that ensures that the knee joint does not become damaged during years of weight-bearing exercise. The meniscus is located between the femoral condyle and the tibial plateau and acts as a cushion, protecting the joint surface of both and absorbing downward transmitted shock, especially during hyperflexion or extension. When jumping from a height, the knee is subjected to considerable force from the body’s gravity, but the cartilage of the femoral condyle and tibial plateau is not damaged because the presence of the meniscus spreads this force over the entire knee joint at the same time, rather than being limited to a restricted point on the tibial plateau where the femoral condyle touches the tibial plateau. In addition, the meniscus prevents displacement of the femur because its wedge shape compensates for the disproportion between the femoral condyle and tibial plateau by filling the dead space around the rounded femoral condyle and tibial plateau, thus increasing the stability of the knee joint and preventing the joint capsule and synovial tissue from entering between the articular surfaces. The meniscus also prevents the femoral condyle from sliding forward on the tibial plateau, regulating the pressure in the knee joint, and the meniscus is covered with a lubricating fluid that reduces friction by lubricating all parts of the joint. The meniscus itself is very flexible and remains so when it is compressed from 5mm to 2.5mm, its bowed shape allows the edge of the joint cavity to better support the synovial capsule. The meniscus also supports the rotational movements of the knee by assisting the lateral collateral ligaments in controlling the lateral motion of the joint and aiding in the rotational motion of the joint. The outer edge of the meniscus is thick and heals closely to the joint capsule, while the inner edge is thin and free; it is slightly depressed above, toward the femoral condyle, and flat below, toward the tibial condyle. The medial meniscus is large and thin, with a “C” shape, narrow at the anterior end and wide at the posterior part. The anterior end starts from the anterior portion of the anterior tibial intercondylar fossa and lies anterior to the anterior cruciate ligament. The posterior end attaches to the posterior intercondylar fossa and lies between the lateral meniscus and the attachment point of the posterior cruciate ligament, with the edges closely healed by the fibrous layer of the joint capsule and the lateral tibial collateral ligament. The lateral meniscus is small, annular in shape, broad in the middle and narrow anteriorly and posteriorly. The anterior end of the meniscus is attached to the anterior intercondylar fossa and is located on the posterior aspect of the anterior cruciate ligament. The posterior end of the meniscus ends at the posterior intercondylar fossa and is located in front of the posterior end of the medial meniscus. The meniscus has a certain degree of elasticity, can cushion gravity, and plays a role in protecting the joint surface. The presence of the meniscus divides the knee cavity into upper and lower cavities that are not completely separated, which makes the joint head and fossa more adaptable and increases the flexibility of movement, such as flexion and extension movements mainly in the upper cavity, while the lighter gyratory movements during knee flexion are mainly done in the lower cavity. In addition, the meniscus has a certain degree of mobility, moving backward during knee flexion and forward during knee extension. This is prone to injury and even tearing when there is a strong and sudden movement. When the knee joint is flexed and the tibia is fixed, the lower end of the femur may tear the medial meniscus due to sudden excessive rotation and extension due to external forces; similarly, the lateral meniscus may also rupture if the lower end of the femur is suddenly externally rotated and extended at that time. Meniscal injury symptoms 1, most patients without a history of trauma, gradually swelling after the injury, the injured side is more significant; pain often occurs in a certain position in the movement, the pain may disappear after the position change. The pain site is in both sides of the joint space; walking can be, but weakness, especially when going up and down stairs, and accompanied by pain or discomfort. In those with a long course of disease, the quadriceps muscle will gradually atrophy; interlocking symptoms. 2, in acute injuries, there is synovial injury to the inner wall of the joint capsule, causing intra-articular bleeding and exudate. After the injury, the joint gradually swells and continues to be painful. After rest and general swelling and pain relief treatment, the symptoms are reduced, but the joint space is still painful, especially when the joint is extended and flexed to a certain position. When walking, especially going up and down stairs, I feel weakness in the lower limbs and often hit the weak leg, which affects work and life. Over time, the thigh muscles atrophy and the circumference becomes thin. Some patients suddenly feel abnormal pain in the knee joint when walking, unable to move, or even fall down. After tolerating the pain and moving the lower leg, they can resume walking again. This symptom is called joint interlocking and is caused by the damaged meniscus jamming the joint. In some patients, the knee joint feels bouncy when moving and a popping sound is heard. Meniscus injury daily rehabilitation considerations 1, early diagnosis and treatment in a timely manner, no large hematoma, symptoms are not serious, such as no knee “card”, “interlocking” phenomenon, no quadriceps atrophy phenomenon, middle-aged and elderly patients or doctors according to MRI judgment If the patient does not need surgery, surgery may not be required. Some of these people can participate in sports like normal people, but only after one and a half to two years. 2, athletes or sports enthusiasts still want to continue to play sports, surgery is usually recommended, but surgery is not a simple matter, in addition to the high cost, the recovery process also requires individuals to carry out scientific rehabilitation exercises. In addition, what cannot be ignored is that the surgery itself is a large trauma with rules, and a few people will have a certain degree of limitation in knee function after surgery. 3, in addition to pay attention to the sports posture and the intensity of the exercise, pay attention to sports protection, such as wearing sports brace to prevent accidental injury in sports. 4. In daily life, it is important to anticipate the possibility of accidents and make full use of the tools around you to help reduce the risk of meniscal injury caused by accidents. For example, when getting on and off the bus or going up and down the stairs, do not be in too much of a hurry, you can use the handrail to help stabilize your body before taking steps, and people with professional habits, it is best to change your posture and take a short break every once in a while.