Knee meniscus injury

　　The meniscus injury of the knee joint is often caused by a twisting external force. When one leg bears the weight, the lower leg is fixed in a semi-flexed, abducted position, and the body and thigh are suddenly internally rotated. The medial meniscus is subjected to rotational pressure between the femoral condyle and the tibia, leading to meniscus tear. If the degree of knee flexion during the twist is greater, the tear site is more posterior. The mechanism of lateral meniscus injury is the same, but the direction of the force is opposite. If a torn meniscus partially slides into the joint space, it causes mechanical obstruction of joint movement, impairs joint extension and flexion, and forms a 'locking'. In severe trauma cases, the meniscus, cruciate ligament, and collateral ligament may be injured simultaneously. The site of meniscus injury can occur in the anterior angle, posterior angle, middle or marginal part of the meniscus. The shape of the injury can be transverse, longitudinal, horizontal, irregular, or even broken into loose bodies within the joint.

　　The meniscus injury of the knee joint mainly causes joint pain and dysfunction. In severe cases, it may lead to symptoms of knee locking, which refers to the limitation of flexion and extension of the knee joint in a certain posture, accompanied by significant pain. Therefore, patients with this disease should be treated actively to prevent the occurrence of complications.

　　Meniscus injury of the knee joint is a common disease of the knee joint. The meniscus is located on the articular surface of the tibia, with an inner and outer meniscus shaped bone. What are the symptoms of meniscus injury of the knee joint?

　　The disc-shaped meniscus is thicker and more prone to injury, often bilaterally. The main symptoms are clear and crisp popping sounds during joint movement. During joint movement, a mass can be felt at the lateral meniscus, with tenderness. After meniscus injury, mucinous degeneration can produce meniscus cysts, with symptoms similar to meniscus injury, with a local mass, and the mass is more obvious when extending the knee.

　　Meniscus injury of the knee joint is a common disease of the knee joint. This disease is a traumatic disease, often caused by a twisting external force. The main method of preventing this disease is to pay attention to safety and avoid trauma.

　　Meniscus injury of the knee joint is a common disease of the knee joint. There are many examination methods for this disease. The following is an introduction:

　　1. Tenderness Site

　　The site of tenderness is generally the site of the lesion, which is of great significance for the diagnosis of meniscus injury and determining the site of injury. During the examination, the knee is placed in a semi-flexed position, and the patella is pressed point by point from the front to the back along the superior margin of the tibial condyle (i.e., the edge of the meniscus). Fixed tenderness is present at the site of meniscus injury. If the knee is passively flexed and extended or internally and externally rotated while pressing, the pain becomes more pronounced, and sometimes an abnormally moving meniscus can be felt.

　　2. McMurray Test (Rotary Compression Test)

　　The patient lies on their back. The examiner holds the lower leg ankle with one hand and supports the knee with the other hand, flexing the hip and knee as much as possible. Then, the lower leg is externally rotated, externally adducted, and internally rotated, or internally adducted and internally rotated, or internally adducted and externally rotated, and gradually extended. Pain or a sound indicates a positive result. The location of the pain and sound determines the site of the injury.

　　3. Forceful Overextension or Overflexion Test

　　Passively overextend or overflex the knee joint. If the anterior part of the meniscus is damaged, overextension can cause pain; if the posterior part of the meniscus is damaged, overflexion can cause pain.

　　4. Lateral Compression Test

　　With the knee extended, forcibly passively adduct or abduct the knee joint. If there is a meniscus injury, pain at the interval of the affected side is caused by compression.

　　5. Single-Leg Squat Test

　　Stand with one leg supporting the weight and gradually squat down from a standing position, then stand up from a squatting position. The healthy side is normal, but when the affected side squats or stands up to a certain position, pain at the joint interval can be caused by the compressed damaged meniscus, which may even prevent squatting or standing up.

　　6. Gravity Test

　　The patient assumes a lateral decubitus position, lifts the lower limb to perform active flexion and extension of the knee joint. When the interval of the affected side is downward, pain is caused by the compressed damaged meniscus. Conversely, when the interval of the affected side is upward, there is no pain.

　　7. Friction Test

　　The patient assumes a prone position, with the knee joint flexed. The examiner holds the ankle with both hands and presses the lower leg downward while performing internal and external rotation movements. Pain is caused by the damaged meniscus due to compression and friction. Conversely, if the lower leg is lifted upwards and internal and external rotation movements are performed, there is no pain.

　　8. X-ray Examination

　　Taking X-ray films in anteroposterior and lateral positions cannot show the condition of meniscus injury, but can exclude other bone and joint diseases. Arthrography is of little diagnostic significance and can increase the patient's pain, so it is not recommended to use it.

　　9. Knee Arthroscopy

　　Arthroscopy can directly observe the location, type, and condition of other structures within the joint, which is helpful for the diagnosis of difficult cases.

　　Patients with meniscus injury of the knee joint should eat less greasy and high-fat foods and more vegetables and fruits in their diet. They should eat less refined grains and more coarse grains, and active, scientific, and reasonable diet is conducive to the recovery of the disease.

　　Meniscus injury of the knee joint is a common disease of the knee joint. The disease can be treated differently according to different stages:

　　1. Acute Stage

　　If there is obvious joint effusion (or hemorrhage), it should be aspirated under strict aseptic conditions; if the joint has 'locking', the 'locking' should be released manually, and then the knee joint is fixed in extension with a cast from the upper third of the thigh to the ankle for 4 weeks. The cast should be properly shaped, and the patient can walk with the cast. During the period of fixation and after the removal of the fixation, active exercise of the quadriceps muscle should be carried out to prevent muscle atrophy.

　　2. Chronic Stage

　　If non-surgical treatment is ineffective, and symptoms and signs are obvious with a clear diagnosis, the damaged meniscus should be surgically removed early to prevent the occurrence of traumatic arthritis. After surgery, the knee joint is bandaged in extension and pressure, and the quadriceps static contraction exercise begins the next day. After 2-3 days, straight leg raising exercises begin to prevent atrophy of the quadriceps muscle. Walking on the ground begins after two weeks, and normal function is usually restored within 2-3 months after surgery.

　　3. Application of Arthroscopy

　　Arthroscopy can be used for the treatment of meniscus injury. Meniscus edge tears can be sutured and repaired, and usually partial meniscectomy is performed to retain the undamaged part. Emergency arthroscopy can be performed for those suspected of meniscus injury early, to treat meniscus injury early, shorten the course of treatment, improve the effectiveness of treatment, and reduce the occurrence of traumatic arthritis. Arthroscopic surgery has minimal trauma and fast recovery.