| Part one Establishment of animal model of chronic compressive cervical spondylotic myelopathy and Study on the expression of inflammatory factorsObjective: a rat model of chronic compressive cervical spondylotic myelopathy(CSM)was established to explore the relationship between cervical degenerative lesions with different degrees of compression and the expression of confirmatory factors.Methods: 3 group of fitness male rats were stochastic assigned as matched group(n=10),mild compression group(n=30)and severe compression group(n=30).In the model group,the interlaminar ligaments were excised under the C5-C7 lamina,and carefully placed into 1.6mm×0.8mm×0.4mm and 5.5mm×1.6mm×0.8mm,respectively two different size of water absorbent materials,PVA,IPN hydrogel,mild compression group and severe compression group model were established.At the same time,in the model group,part of the posterior cervical muscles were removed to accelerate cervical degeneration.The rats in the control group were not placed in the hydrogel,and 6 rats were stochastic chosen at fourth,eighth and 12 weeks Post-op.The rats were subjected to the inclined plate climbing test.After they were executed,the C5-7 segment of the intervertebral disc and spinal cord were taken out.HE stain was applied to look into the changes histological of the medulla spinalis in the corresponding segments.TUNEL staining was applied to test the apoptotic cells.Then the PCR group and the Western blot way were applied to test the content of protein and m RNA of TNF-?,IL-1?,IL-33 and IL-6 in C5-7 between the model group and the matched group.Results: the consequence of slope climbing test indicate that there was no Statistical differences in the motor function between the matched group and the Preoperative matched group at 4,8 and 12 weeks Post-op(P > 0.05),but the inclined plate angle that the rats in each model group could bear decreased after operation,and there was Statistical differences between the two groups at8 and 12 weeks Post-op(P < 0.05).HE staining of rat's spinal cord,At the 4th week after operation,there was no Statistical differences in the degeneration degree of spinal cord tissue morphology between the compression model group and the control group(P > 0.05).Compared with the control group,at the 8th week after operation,the mild compression group had more degeneration and atrophy than the control group,while the severe compression group had less morphological cells,obvious shrinkage,demyelination and vacuolar degeneration;at the 12 th week after operation,the mild compression group had more severe degeneration than the control group,with severe demyelination and vacuolar degeneration of axons Neuronal cell necrosis,diffuse demyelination and axonal vacuolar degeneration(P < 0.05).At the same time,there was obviously increase about the positive cells in model group than which in the corresponding matched group,At 8 and 12 weeks after operation,the m RNA and protein content of IL-1?and other factors in the intervertebral disc of the model group were high,and the expression levels were up-regulated with the degree of compression and modeling time.Conclusion:The results showed that polyvinyl alcohol polyacrylamide interpenetrating polymer network hydrogel was used as compression material to establish a chronic spinal cord compression model of cervical spondylotic myelopathy in rats.The injure of the spinal cord increased as the time of modeling,and the inflammatory factors were highly expressed in the intervertebral disc of the model rats with different modeling time,and the expression level increased significantly with the extension of the degenerative degree or compression time.Part two Clinical application of large channel endoscopic ecompression in posterior cervical spine disordersObjective: to estimate the clinical effect of posterior large channel endoscopic decompression in cervical spondylosis,It provides a new idea for the treatment of CSMMethods: Clinical data from February 2016 to March 2018 were gathered for 32 patients with single-segment CSM or CSR who underwent posterior cervical percutaneous large channel endoscopic decompression and completed a regular follow-up exam at 12 months Post-op.Surgical information(duration of surgery,blood loss,patient bed days,complications,etc.).The JOA and VAS were used to evaluate the results of operation for everybody.Cervical spine radiographs were used to evaluate cervical curvature(Cervical spondylotic angle(CSA),C2–7Cobb angle)and CT and MRI were used to assess the extent of laminectomy and nerve root decompression.The results were analyzed statistically,and We had put into use the modified Macnab criteria to estimate the clinical effect of large channel endoscopy in posterior cervical at the last follow-up exam.Results: The JOA and VAS scores were compared Pre-op and Post-op(1day Pre-op;3 days,3 and 12 months Post-op).there were Statistical difference(P<0.05).There were statistical difference in cervical curvature(C2-7 Cobb angle)between the time points(1 day Pre-op;3 days,3 and 12 months Post-op),but CSA angle had significant difference only between 3 days Post-op and 1 day Pre-op(P < 0.05).The duration of surgery range was45-110 min(mean 68.6±23.8 min);the intraoperative bleeding volume range was 20-85 ml(mean28±14.8 ml),and the patient bed days was 3-8 days(mean4.5 days).The modified Macnab criteria was used as the final evaluation method of large channel endoscopic decompression.29 patients were great satisfaction,the super rate was 93.75%.3 patients had moderate results.Post-op CT and MRI showed that the compression of the spinal cord or nerve roots was completely relieved.Conclusion: Endoscopic decompression of posterior cervical vertebral disorders is a security,good effect,and small trauma surgical procedure with quicker recover.This procedure warrants additional research and clinical application.Part three Biomechanical finite element analysis of percutaneous endoscopic posterior cervical spine surgeryObjective: To simulate the effect of large channel endoscopic decompression in Posterior Cervical Spine on the mechanical properties of C4-C7 intervertebral disc by three-dimensional finite element method,so as to provide reference for doctors and subsequent experimental research.Methods: A three-dimensional finite element model of large channel endoscopic decompression in Posterior Cervical Spine mechanics was established,and the range of motion and maximum stress of cervical disc segment were verified.Results: In the Post-op model group,the Rom of C4-5 intervertebral disc did not change compared with the normal group.The Rom of C5-C6 segment in the operation model group was increased compared with the normal model group in flexion,extension,left and right bending and left and right rotation.Among them,the left flexion and the right flexion increased by 4.61% and5.13% respectively,while the C6-7 segment increased slightly in flexion,extension and lateral flexion,with the largest increase of 6.07% in right of lateral curvature,and separately,it is 0.5% and 0.11% in left-to-right twisting.After posterior cervical laminectomy,the stress of flexion and extension of C5-C6 segment decreased by 1.64% and 1.77% respectively,and the maximum stress of left flexion,right flexion and left rotation increased by1.64%,1.13% and 1.81% separately.The stress of C4-5 disc remained unchanged,while that of C6-7 disc increased in all directions except flexion The maximum stress increases by 11.43% in the right-hand bending.The results show that the maximum stress of C4-7 model decreases by 4.69% in flexion and 10.08% in extension,and increases in left flexion,right flexion,left rotation and right rotation compared with normal model.The maximum stress of C4-7 model increases by 9.95% in right bending.Conclusion: The PED of the posterior cervical spine maintained stability of the cervical spine,while the stress of the corresponding intervertebral disc was improved during the dynamic movement of the cervical spine,which may promote the degenerative changes of the late cervical spine.Generally speaking,the mobility and maximum stress of each segment after operation can reach or even be better than the original normal state. |
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