How to distinguish between new and old meniscus injuries?

Meniscal injuries are mostly caused by torsional external forces. When one leg is loaded and the calf is fixed in the semi-flexion booth, the body and thigh suddenly rotate inward, and the medial meniscus is between the femoral condyle and tibia, which is subjected to rotational pressure, resulting in meniscus tear. When sprained, the greater the degree of knee flexion, the more backward the tearing position, and the damage mechanism of lateral meniscus is the same, but the stress direction is opposite. If the ruptured meniscus slides between joints, the joint activity will be mechanically hindered, which will hinder the extension and flexion of the joints and form an "interlock". Meniscus injury Meniscus injury can occur in the anterior corner, posterior corner, middle part or marginal part of meniscus. The shape of the injury can be transverse crack, longitudinal crack, transverse crack or irregular shape, or even broken into intra-articular free bodies. Classification includes: edge tearing, transverse tearing, longitudinal tearing, transverse tearing and front and rear corner tearing. Under severe trauma, meniscus, cruciate ligament and collateral ligament can be damaged at the same time. After meniscus injury, the knee joint is painful, unable to straighten automatically, and the joint is swollen. Knee joint space tenderness is an important basis for meniscus injury.

1, most patients have a history of knee sprain. 2. When the knee joint is extended, there is a click in the knee joint. 3. There is a tearing sensation and murmur in the knee joint when injured, that is, severe pain, joint swelling and flexion and extension dysfunction. When walking and going up and down stairs, the pain of knee joint movement is obvious, and some patients may have soft knees and twisted legs. 4. During the examination, muscular atrophy of quadriceps femoris can be found, and there is tenderness in the knee joint space, and the knee joint cannot be overstretched or overstretched. 5. meniscus snap test (Maxwell's sign): the patient lies on his back, fully bends his hips and knees, and the examiner holds his feet with one hand and puts the other hand on his knees. First, the calf is rotated internally, then abduction is straightened, then the calf is rotated externally and abduction is straightened. It is positive if there is pain or click. Most patients are positive. 6. Abrasion test: The patient was prone and the affected knee flexed 90 degrees. The examiner presses the ankle hard and does rotary grinding. It is positive when there is pain in a certain position, and some cases can be positive. If necessary, perform knee arthrography, iodine solution radiography or arthroscopy.

The purpose of 1 X-ray examination is not to diagnose meniscus tear, but to exclude osteochondral separation, osteochondritis exfoliative and other knee joint diseases that may be similar to meniscus tear. Arthrography is a valuable auxiliary means to analyze knee joint diseases. However, due to modern MRI and other non-invasive and high-precision inspection methods, contrast technology has been rarely used at present. 2.MRI is the imaging examination method with the highest sensitivity and accuracy in diagnosing meniscus injury and cruciate ligament rupture, with an accuracy rate of 98%. Meniscus tear's MRI showed low signal intensity in the meniscus, and linear or complex high signal bands crossed the surface of the meniscus. Other imaging diagnostic methods, such as high-resolution ultrasound and high-resolution CT, are also helpful for the diagnosis of diseases in the knee joint. 3. Arthroscopy is recognized as the most ideal method for diagnosis and surgical treatment of meniscus injury. But arthroscopy should not be a routine examination method in meniscus tear. Only after making a preliminary diagnosis of meniscus tear in clinic can arthroscopy confirm the diagnosis, and at the same time, arthroscopic surgery can show its superiority.