动物造模,椎弓椎体截骨矫正驼背动物模型 z-bio 2021-03-30 256

　　(1) Reproduction method Anesthetize rats by intraperitoneal injection of 1% barbiturate at a dose of 30%/kg body weight. The animal extends into the spine in a stereotaxic direction to fix the skull and transverse processes on both sides of T11 to L4, and perform a posterior midline incision to expose T12? L3, and from T12? Vertebral osteotomy is performed on both sides of L3. (1-2 vertebral bodies, 3-4 vertebral arch plates). Do not damage the spinal cord and nerve roots. Keep the dura mater intact. Observe the changes of the spinal cord from the removed upper and lower lamina, and adjust the spine positioning device to relax the spine along the vertical axis of the spine, and gradually retract it into the spinal canal, thereby causing injury. It shortens the spine at a speed of 2 m/30 minutes, and uses a vernier caliper and a stereotaxic device. Determine the shortened distance.

　　(2) The model features can record stable spinal motor evoked potentials (MEP, SEP) before shortening the spine. When the spine was shortened by 4 mm, there was no significant change in MEP. When the spine is shortened by 4 mm. , The peak delay is extended by more than 10%, and the amplitude is reduced by 50%. Above %, 60% of the volatility disappears. At 8mm, only part of the trace remains in the MEP, and more than 90% of the waves disappear. The trend of SEP is similar to that of MEP, but to a lesser extent. When shortened by 6 mm, blood vessels were significantly dilated, blood flow slowed down, blood clots were visible, red blood cell agglutination was seen, and peripheral bleeding was visible. Vascular congestion; in the process of shortening the spine, the blood flow in the gray matter of the compressed segment (T13) and the adjacent segment (L1) gradually decreases. When observed with the naked eye, the shortened spinal cord showed progressive longitudinal comb-like expansion, the spinal cord became loose, horizontal folds appeared, and spread in the adjacent vertebral bodies, increasing with increasing compression. If you shorten it by 4 mm, you will see blood oozing out like small spots. It is 6 mm short, with multiple local bleeding points around small capillaries, more gray matter bleeding points, fewer white matter bleeding points, and central tube malformations. Obvious hemorrhage and local posterior spine hemorrhage, accompanied by white matter rupture, severe hemorrhage and venous thrombosis, nerve cells are eosinophils, black basal nucleus cell bodies are open, and staining ability is lost. Typical shadow cells, nerve fibers appear Foamy changes, axon protoplasmic fracture; when shortened by 8 mm, extensive diffuse bleeding is seen, and the structure is unclear.

　　(3) Comparative medicine According to the characteristics of the longitudinal movement of the spinal cord from the osteotomy part to the spinal canal, the thoracolumbar region of the rat is selected to simulate the pedicle osteotomy. When the spine is shortened and relaxed to a certain extent (about 6 mm), the spinal cord at the osteotomy site will be neurologically dysfunctional and spread to the upper and lower vertebral bodies, mainly manifested as congestive ischemia. When multiple osteotomies are used clinically, each two must be adjacent to multiple vertebral bodies, so that the spinal cord function is not affected by the adjacent osteotomies and has an overlapping effect. At the same time, it has been proposed that there is a limit to shortening the spine after osteotomy. If it is too large, it will cause irreversible damage. Clinically, it should not be used to correct the angle of a large osteotomy. However, it should be divided into appropriate osteotomies to improve the overall effectiveness of the osteotomy.