动物模型,佩尔斯特病 z-bo 2020-08-10 582

　　Perthes disease refers to avascular necrosis of the femoral head in children, which is part or all necrosis of the femoral skull epiphysis caused by blood flow disorder of the femoral head. After the lesion is static, the flattened deformity of the femoral head is often left, which affects the function of the hip joint.

　　(1) Reproduction method After anesthetized experimental rabbits with 30% urethane intravenously, they were fixed on the operating table, the left hip was shaved, the skin was routinely disinfected, and a drape was placed for sterile surgery. Make a 6cm incision on the posterolateral side of the hip. After cutting the skin, go through the posterior quadratus muscle space of the greater trochanter of femur into the deep layer and reach the hip joint capsule. Cut the nodular capsule, cut off the round ligament of the femoral head, and dislocate the femoral head. With a sharp knife, the supporting blood supply of the femoral neck was cut off and the supporting belt was stripped down to the level of the intertrochanteric line. After it was confirmed that all supporting blood supply of the femoral head was interrupted, the hip joint was reset and the incision was sutured layer by layer. 800,000 U of penicillin was intramuscularly injected after surgery for 3 days.

　　(2) Characteristics of the model. The surface of the femoral head was tarnished by naked eyes 2 weeks after the operation, and the cartilage part lost its translucent appearance, and was slightly pale, especially near the stop point of the round ligament of the femoral head. The femoral head was pale and obvious 4 weeks after the operation, and some were grayish yellow. X-ray examination showed that the femoral head density of the affected side increased and the epiphysis height decreased slightly in the 4 weeks postoperative group, and the femoral head density increased and the epiphysis height decreased significantly at 8 weeks postoperatively. The epiphyseal lines of some specimens were blurred. Bone imaging showed that the radioactive uptake of all specimens increased significantly at 4 and 8 weeks after surgery; MRI showed that the low signal area of the femoral head increased, and the signal gradually became uneven, mixed with high signal, and the structure of the epiphyseal plate was unclear. Pathological examination showed that the bone lacuna was empty 2 weeks after the operation, and the bone marrow tissue was dissolved, fragmented, and disappeared. Fibrogranulation containing undifferentiated mesenchymal cells and capillaries was invaded and began to replace the necrotic bone marrow tissue, but it was not obvious yet New bone formation; proliferation of undifferentiated mesenchymal cells and capillaries increased at 4 weeks after surgery, mesenchymal cells differentiated into osteoblasts on the surface of the dead bone, new bone began to form on the dead bone, and the articular cartilage matrix appeared light After 8 weeks, there are still mesenchymal cells on the surface of some dead bones that differentiate into osteoblasts, but their repair activity is reduced. Scattered cartilage necrosis can be seen, and the cartilage matrix is lightly stained.

　　(3) Comparative medicine The X-ray manifestations of this model at 4 and 8 weeks after surgery are similar to those of human Persteer's disease, but no epiphyseal fragmentation is found. The rabbit is a four-legged animal. The postoperative pain and weight bearing of the affected limb are reduced, and the stress reduction caused by the caged animal may be one of the factors. MRI showed that the low signal range expanded and gradually lost uniformity, indicating the coexistence of osteonecrosis and repair in the model animals at this time, the coexistence of new bone formation and fibrous granulation, resulting in the complexity of the signal, and also a good simulation of the MRI performance of Peelster’s disease . The basic pathological changes and bone imaging of this model also have the characteristics of human Perst disease.