Knee extension disorder

Introduction Knee extension is a clinical manifestation of knee arthritis. Knee arthritis: can be single, or bilateral, more women and often overweight. Symptoms after middle age: When sitting up and standing, I feel that my knees are sore and uncomfortable. When I walked for a while, my symptoms disappeared. This is an early manifestation. The development of the disease, the activity can not alleviate the pain, and it should be difficult to get up and down the stairs or the squat and the station. You need to support your knees. After walking more, the knee joint is swollen, or swollen, and some light yellow liquid can be extracted. Because the synovial membrane and the joint capsule have lesions and thicken, there may be sound when moving. If there is a loose body formed in the joint, it may affect the joint activity, and sometimes there is a "joint lock" phenomenon. At the end of the knee deformity, such as knee flexion contracture, O-legs or X-legs, and even crutches can walk.

Cause

Not completely clear. Rheumatoid arthritis is a disease that is closely related to factors such as the environment, cells, viruses, genetics, sex hormones, and neuropsychiatric states.

(1) Bacterial factors: Experimental studies have shown that group A streptococci and peptidoglycan may be a persistent stimulator of RA, and group A streptococci have long-lasting antigens in the body, stimulating the body to produce An antibody that causes immunopathological damage and causes disease. The arthritis animal model produced by Mycoplasma is similar to human RA, but does not produce rheumatoid factor (RF) specific to human RA. Bacterial or bacterial antigenic material has never been found in the synovial fluid and synovial tissue of RA patients, suggesting that bacteria may be involved in the onset of RA, but lacks direct evidence.

(2) Viral factors: The relationship between RA and viruses, especially EB virus, is one of the issues that scholars at home and abroad pay attention to. Studies have shown that arthritis caused by EB virus infection is different from RA, and RA patients have strong reactivity with EB virus than normal people. There is a persistently high level of anti-EBV-membrane antigen antibody in serum and synovial fluid of RA patients, but so far no Epstein-Barr virus nuclear antigen or capsid antigen antibody has been found in the serum of RA patients.

(3) Genetic factors: The disease has a high incidence in some families. In the population survey, human leukocyte antigen (HLA)-DR4 was found to be associated with RF-positive patients. HLA studies have found that DW4 is associated with the pathogenesis of RA. 70% of patients are HLA-DW4 positive, and patients have susceptibility genes at this point, so inheritance may play an important role in the pathogenesis.

(4) Sex hormones: Studies have shown that the incidence of RA is between 1:2 and 4, the condition of pregnancy is reduced, and the incidence of contraceptives is reduced. Animal models show that LEW/n females have high sensitivity to arthritis and low male incidence. After male rats are treated with castration or treated with -estradiol, arthritis occurs in the same way as female mice, indicating that sex hormones are in RA. It plays a role in the onset.

Cold, damp, fatigue, malnutrition, trauma, mental factors and other cold, damp, fatigue, malnutrition, trauma, mental factors, etc., often lead to the disease, but most patients often have no obvious incentives.

an examination

Related inspection

X-ray lipiodol angiography bone and joint soft tissue CT examination

The main clinical manifestation of knee arthritis is pain. When the joints are loaded with weight, the hips and knee joints are sorely swelled when going downstairs or when the chin is raised. In the early stage of the disease, joint pain can be relieved after rest, but with the development of the disease, even the pain is more obvious at rest, and even limp, affecting daily activities. The second aspect of clinical manifestations is joint stiffness, such as hip or knee stiffness during morning or sedentary standing. The third aspect of clinical manifestations is dysfunction, which can cause muscle atrophy, joint deformity, and eventually dysfunction. If X-ray examination is performed, it is found that the joint space is narrowed, bone hyperplasia at the joint edge, irregular articular surface, and joint deformity. Knee osteoarthritis to the late stage of the drug can only slightly relieve pain, to solve the problem of walking, it is best to replace the artificial joint.

Differential diagnosis

The inability to fully extend the knee joint is a clinical manifestation of knee collateral ligament injury. The joint capsule of the knee joint is weak, and the stability of the joint mainly depends on the ligament and muscle. The medial collateral ligament is the most important, followed by the lateral collateral ligament and the anterior and posterior cruciate ligaments. Post-knee swelling and pain, activity-limited axillary cysts are more common in middle-aged cases. The incidence is higher in men and women, more men than women, resulting in mechanical knee extension and knee flexion limitation, less pain, and a sense of tension and swelling. The patient's complaint is often characterized by a gradual swelling of the axillary area with pain in the back of the knee. Occasionally cysts can be oppressed to block venous return, causing calf edema. When the cyst grows to a certain extent, the knee flexion and extension activity is limited. Knee and sacral reflexes are clinical manifestations of lumbosacral neuritis.

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