The meniscus is the wedge-shaped elastic lining that connects the femur and tibia of the knee joint and is one of the most vulnerable parts of the knee joint. The medial meniscus is “C”-shaped and the lateral meniscus is “O”-shaped, and is used to support weight, assist the knee joint in sliding and steering, and prevent direct friction between the femur and tibia, stabilize the joint, absorb shock, and protect the articular cartilage surfaces. Soccer players and others involved in competitive sports are susceptible to meniscal injuries during knee flexion, rotation, stopping and deceleration. Meniscal injuries in athletes may often be combined with other injuries, such as anterior cruciate ligament injuries. In older adults, meniscal injuries can occur in the absence of any trauma as the cartilage degenerates and wears away. Signs and Symptoms A meniscal injury may be associated with a popping sound, most people can continue to walk, and athletes may continue to play sports. When reactive inflammation occurs with a knee injury, pain and stiffness in the knee joint may occur. After a few days there may be: 1. stiffness and swelling. 2. Knee joint line pressure pain. 3. Fluid accumulation in the knee joint. Without proper treatment, the broken meniscus fragments can loosen and free, resulting in a feeling of joint entrapment, popping or interlocking. The knee joint is often unable to extend and flex the knee joint at 45° of flexion, i.e. knee joint interlocking, which can sometimes be relieved by hand thrusting. When a meniscal injury is felt to have occurred, it should be diagnosed and treated immediately. Diagnosis Inform the knee of the condition and timing at the time of injury. Perform a physical examination to determine the extent of the meniscus injury. X-rays may be taken to rule out osteoarthritis or other conditions causing knee pain. Magnetic resonance imaging (MRI) can obtain clear soft tissue images of the knee joint, and knee arthroscopy techniques may also be used to examine the knee joint for a definitive diagnosis when the knee is interlocked. There are several ways in which meniscal injuries can occur: 1. Longitudinal or “barrel stem” type injuries often occur in young athletes during knee rotation. 2. Younger athletes with sustained knee stress may have radial or beak-like compound injuries to the meniscus (less common). In older adults, due to aging cartilage, meniscal injuries often begin with a tear at the medial edge of the meniscus. Conservative treatment Early meniscal injuries can be treated with rest, ice, compression bandages, elevation of the affected limb, and oral non-steroidal drugs to relieve pain. If the knee is stable and there are no symptoms of interlocking, then conservative treatment is sufficient. The meniscus is rich in blood flow around its periphery, and this part of the injury has the potential to heal itself, so small injuries to the meniscus periphery may heal themselves after rest. Surgery When the meniscus does not heal on its own and the knee becomes painful, stiff or interlocked, surgery is required. Due to the importance of the meniscus within the knee joint, surgery should preserve as much of the meniscus as possible. The application of knee arthroscopic techniques greatly reduces the trauma of knee surgery and increases the accuracy and precision of the procedure. Currently, depending on the type of meniscal injury, the presence of cruciate ligament injury, and age and other factors, the surgeon will selectively perform meniscal repair, partial resection, and major resection depending on the situation. After surgery, the knee can gradually return to daily activities after completing functional exercises.