Anterior cruciate ligament injury

　　The main cause of anterior cruciate ligament injury is sports injury, accounting for more than 70%. When the knee joint is forcibly overextended or abducted, it can cause anterior cruciate ligament injury. The most common sports are basketball and football, and it is also common in professional athletes engaged in judo, wrestling, and track and field, as well as in ordinary people who enjoy skiing, badminton, and volleyball. Non-sports injuries, including traffic accidents and accidental injuries in daily life, account for about 27%.

　　Failure to receive timely treatment for a ruptured anterior cruciate ligament or recurrent sprains can easily lead to secondary damage to the knee joint.

　　1. Medial and lateral meniscus injury inside the knee joint

　　The meniscus is a crescent-shaped fibrocartilage inside the knee joint, located between the articular surface formed by the tibia and femur, which increases the contact area between the femoral condyle and the tibial plateau, thereby enhancing the stability of the knee joint. After the anterior cruciate ligament is ruptured, due to the forward instability of the knee joint, especially repeated sprains, the meniscus may produce contradictory movements, leading to secondary injury to the meniscus.

　　2. Knee cartilage injury

　　Long-term instability and recurrent sprains can lead to degenerative changes in the patellofemoral cartilage within the knee joint.

　　3. Osteophyte formation and chronic synovitis

　　Patients with severe trauma may feel a tearing sound inside the knee joint, followed by weakness and severe pain in the knee joint, rapid swelling, and blood accumulation within the joint. Subcutaneous ecchymosis around the joint often indicates joint capsule injury and dysfunction. Patients with chronic injuries may experience atrophy of the quadriceps femoris muscle and a decrease in motor ability.

　　The prevention of this disease should pay attention to the protection of the joints, do not wear high heels, and can wear a knee brace to protect the joints. In addition, attention should be paid not to over fatigue the ankle ligaments, especially when climbing stairs or mountains.

　　The main examination methods for anterior cruciate ligament injury include the following:

　　1. Lachman test.The patient lies flat, the knee is flexed 15° to 20°, and both feet are placed on the bed. The examiner holds the distal end of the femur with one hand and the proximal end of the tibia with the other hand, making opposite forward and backward movements. If there is more than the healthy side's forward movement, it is positive.

　　2. X-ray examination of the knee.X-ray examination shows a torn intercondylar eminence fracture of the tibia. During varus and valgus stress testing, one side of the joint space can be seen to be widened.

　　3. Knee MRI.

　　4. Knee arthroscopy.

　　Patients with this disease should choose light foods in their diet, such as various soups. Spicy and刺激性 food and seafood should be avoided as they can worsen joint congestion and swelling. Patients can eat more high-protein foods such as fish, chicken, and duck, and at the same time, eat more foods rich in vitamin C, which can promote the healing of the injury.

　　Surgical repair during the acute stage will exacerbate trauma and affect postoperative joint function, so conservative treatment can be performed early.

　　I. Non-surgical Treatment

　　For simple anterior cruciate ligament rupture or incomplete rupture, the injured knee can be immobilized in a flexed position of 30° using a cast. Attention should be paid to push the proximal end of the tibia of the injured side backward before the cast is shaped, and it should be fixed for 4 to 6 weeks. Quadriceps muscle training can begin 3 days after the cast is fixed.

　　II. Surgical Treatment

　　1. For patients with avulsion fractures at the tibia and femur insertion sites that cannot be reduced closed, early surgical reduction should be performed.

　　2. For patients with medial meniscus tear and knee locking that cannot be resolved spontaneously, surgical exploration should be performed.