Treatment Of Complex Cervical Spondylotic Myelopathy By Staged Anterior And Posterior Approach

AIMStaged anterior and posterior surgery can be selected for complex cervical spondylotic myelopathy,but the treatment scheme of staged surgery has not yet reached a consensus.The purpose of this study was to compare the clinical efficacy of staged anterior and posterior surgery and simple anterior or posterior approach surgery in patients with complex cervical spondylotic myelopathy,and to explore the surgical sequence,the timing of secondary surgery and the influencing factors of secondary surgery.METHODSA retrospective comparative analysis was conducted on 27 patients with complex cervical spondylotic myelopathy(observation group)treated by staging anterior and posterior surgery in our hospital from 2009 to 2020,and 40 patients with complex cervical spondylotic myelopathy treated by single surgery(control group).The gender,age,operation sequence,two operation intervals,postoperative complications,preoperative and postoperative Japanese Orthopaedic Association(JOA)scores and follow-up JOA scores of the two groups were recorded.The imaging evaluation included-the first preoperative MRI-T2WI intramedullary high signal classification(T2WI ISI classification),anterior spinal canal encroachment rate,and spinal cord compression rate(CR).The C2-C7Cobb angle,T1 slope angle(T1S),C2-C7 Sagittal vertical axis(SVA),and C3-C6Pavlvo ratios were measured before and after operation.RESULTSThe observation group included 27 cases,18 males and 9 females,with an average age of 60.8±8.9 years(37-74 years)and preoperative JOA score of 11.04±3.02.The control group included 40 cases,25 males and 15 females,with an average age of 57.3±10.4 years(3 8-76 years).The preoperative JOA score was 12.00±2.70.All patients were followed up for at least 12 months.The observation group was followed up for 22.2(12.0,34.9)months,and the control group was 24.3(16.8,27.2)months.The Pavlov ratio of each segment in the observation group was significantly lower than that in the control group,and the ISI grade on T2WI was significantly higher than that in the control group.There was no significant difference in sex ratio,age and follow-up time.All patients in the observation group received two surgical treatments,including 14 cases of anterior surgery and 13 cases of posterior surgery.The control group received one operation,20 cases of anterior and posterior surgery.Anterior surgery using ACDF or ACCF,posterior surgery choose posterior single open-door laminoplasty or laminectomy pedicle screw fixation.The interval between two operations in the observation group was 148(101,534)days.The JOA score of the observation group increased significantly after two operations,and the Pavlov ratio increased.The JOA scores of the two approaches in the observation group increased significantly after the first operation.The C2-C7 cobb angle in the posterior group decreased and the Pavlov ratio increased,while there was no significant change in the anterior group.The JOA scores of the control group after the two approaches were significantly increased.The C2-C7cobb angle of the anterior approach group increased,while the C2-C7cobb angle and T1 tilt angle of the posterior approach group decreased,and the Pavlov ratio increased.The above changes were statistically significant.The first postoperative improvement in the observation group was compared with that in the control group.The Pavlov ratios after the two approaches in the observation group were lower than those in the control group,but there was no significant difference in the difference of Pavlov ratios between the two groups before and after operation.After the first operation,the improvement rate of JOA in the observation group was significantly lower than that in the control group,while after the second operation,there was no significant difference in the improvement rate of JOA between the observation group and the control group.The correlation analysis between the JOA improvement rate after the first operation in the observation group and the control group and the preoperative imaging parameters in the two groups showed that the JOA improvement rate was positively correlated with the Pavlov ratio and negatively correlated with the T2SI grade,that is,the narrower the preoperative spinal canal was,the more serious the spinal cord degeneration was,and the worse the JOA improvement rate after operation was.CONCLUSIONSStaged anterior and posterior surgery is a safe and effective treatment for complex cervical spondylotic myelopathy.The choice of the first surgical approach needs to be combined with the actual situation of patients and the experience and habits of the surgeon.The second operation was mainly due to the poor JOA improvement rate after the first operation.The JOA improvement rate was related to the degree of cervical spinal stenosis and spinal cord degeneration before operation.The timing of the second operation should be determined according to the recovery of neurological function after the first operation and the symptoms of spinal nerve compression.