Experimental Study Of The Effect Of New Spinal External Fixator On The Operation Injury Of The Paraspinal Muscles In Goat

Background:Along with the development of science and technology,traffic accidents and high fall injuries occur frequently,which often occur with thoracolumbar fractures.However,the traditional open internal fixation surgery has been criticized by many scholars for its large trauma and bleeding.A new type of spinal external fixator,developed by the Department of spinal surgery in the First Affiliated Hospital of University of South China,has achieved the requirements of traditional open internal fixation for vertebral fracture,pulling,prying reduction and so on.At the same time the operation through the long arm of pedicle screw fixation and external fixation device in a minimally invasive way to reduce soft tissue injury.Objective:To verify the advantages of the new external fixator operation in reducing the injury of the para spinal muscles by the traditional internal fixation,and to explore the specific mechanism of this advantage.Method:A total of 10 local crossbred goats,weighing 20 ± 2 Kg,were randomly divided into two groups.After 3 months of operation,the 3.0T MRI scan was performed on the lumbar vertebrae,and the para muscle tissue was completely dissected.Then the quasi static tensile test was carried out.Finally,the paraffin sections of the lateral para spinal muscles were stained with HE and Masson.Result:The successful construction of a new spinal external fixation group and a traditional open internal fixation control group with 4 animals in each group.In the experimental group,a few scar tissue appeared around the screw,while a lot of scar tissue appeared in the control group,and there was almost no normal muscle tissue attached to the side of the spinous process.The quasi-static tensile test of the paraspinal muscles suggested that the elastic modulus,ultimate strength and failure strain of the paraspinal muscles in the experimental group were stronger than those in the control group.The surgical segmental magnetic resonance imaging(MRI)showed the results of the muscle anatomy and suggested that the MRI signal of the peripheral spinal muscles in the control group was higher than that of the other parts of the muscle.Paraffin paraffin tissue section HE and Masson staining showed that the muscle tissue surrounding the internal fixation device was seriously damaged,and a large number of fibrous hyperplasia and inflammatory reaction were found in the injured muscle tissue.Conclusions:Through medical imaging,soft tissue biomechanical and histological methods,verify the new spinal external fixation surgery compared with traditional internal fixation nail surgery,through the long arm of percutaneous pedicle screw placement,avoid muscle tendon ligament complex injury caused by extensive dissection.At the same time reduce the postoperative internal fixation device due to extrusion and disturbance induced by chronic inflammatory reaction leads to paraspinal muscle injury.