Pre-operative 3D-CT Measurement And Post-operative 3D-CT Evaluation Of Lumbar Degenerative Diseases Treated By Unilateral Biportal Endoscopy Surgery

Objective 1.Before operation,3D-CT of lumbar spine has the advantages of stereoscopic display and accurate measurement of lumbar spine structure,so as to observe and measure the stereoscopic structure of lumbar spine in order to provide further anatomical basis for UBE technology.2.Follow-up the injury of facet joints in UBE operation by lumbar 3D-CT after operation,and analyze the risk factors of facet joint injuries,so as to reduce the degree of facet joint injuries.Methods 1.Cross-sectional investigation.A total of 50 patients which are diagnosed as "lumbar disc herniation" and treated with "Excision of lumbar disc herniation assisted with unilateral biportal endoscope" were selected from the Department of Spinal surgery of the second affiliated Hospital of Anhui Medical University from January 2019 to June 2020.The three-dimensional CT images of the lumbar vertebrae were reviewed,the overall shape of the lumbar vertebrae was observed and described,and four indexes closely related to the operation process were measured,namely the angle between the laminae on both sides,the width of vertebral lamina,the sagittal degree of facet joint,and the degree of downward movement of vertebral lamina.2.The patients diagnosed as lumbar disc herniation and lumbar spinal stenosis in our hospital from December 1,2020 to May 31,2021,who underwent nucleus pulposus removal of lumbar disc herniation or spinal canal decompression by UBE technology,were followed up with 3D CT within one month after operation.A total of 120 postoperative patients,including 65 males and 55 females;The average age was 55 years old（range: 24-84 years old）,and the degree of articular process injury was evaluated.Results 1.（1）The spinous process is smoothly linked with the bilateral vertebral plates in a herringbone shape,and the bilateral vertebral plates arc out to both sides,and the included angles L3~5 between the two sides of the lamina gradually increase,which are（69.56±11.18）,（77.96±12.23）and（91.82±13.19）mm.（2）The lower edge of the vertebral plates extends to both sides,and the lateral width L3~5 gradually widens and is the same.The left side were（14.04±2.43）、（15.68±2.59）and（18.65±2.76）mm,respectively.The right side were（57.94±11.05）,（48.14±10.42）and（39.90±13.22）mm,respectively.（3）The end of the lamina gradually widened and expanded to form the articular surface,and the articular surface L3/4^L5/S1 gradually changed from sagittal to coronal.There was statistically significant difference between the left and right sides of the same segment compared with L3/4（P <0.05）,but there was no statistically significant difference between the left and right sides of L4/5 and L5/S1（P>0.05）,The right side were（60.40±10.25°）,（49.54±8.76°）and（41.68±10.51°）,respectively;the right side were（57.94±11.05°）,（48.14±10.42°）and（39.90±13.22°）,respectively.（4）The degree of lamina descending gradually decreases,and the difference between L3 and L5 was statistically significant（P <0.05）,with the mean values gradually decreasing to（6.81±2.06）,（5.06±2.26）and（2.44±2.25）mm,respectively.2.Among the 141 lumbar vertebrae composed of 2,120 patients undergoing single and double-level surgery,the degree of injury from grade 0 to grade 4 was 24（17%）,36（26%）,54（38%）,24（17%）and 3（2%）.According to the diagnosis,82 cases were diagnosed as "lumbar disc herniation",and the injury degree of 88 lumbar vertebrae composed of single and double segments was 22 segments,32 segments,28 segments,6segments and 0 segments from grade 0 to grade 4.Thirty-eight cases were diagnosed as "lumbar spinal canal stenosis".Among the 53 lumbar vertebrae composed of single,double and three segments,the degree of injury from grade 0 to grade 4 was 2,4,26,18 and 3 in turn.According to the surgical segment,there are 2 lumbar vertebrae in L2/3,and the degree of injury is Grade 2 and Grade 3 respectively.L3/4 has 14 lumbar vertebrae,and the degree of injury is grade 2,grade 3,grade 3,grade 9,and grade 4,grade 2 respectively.There are 83 lumbar vertebrae in L4/5,and the degree of injury is7 in grade 0,21 in grade 1,43 in grade 2,11 in grade 3 and 1 in grade 4 respectively.There are 42 lumbar vertebrae in L5/S1,and the degree of injury is 17 in grade 0,15 in grade 1,7 in grade 2 and 3 in grade 3 respectively.According to the site of operation,there are 87 lumbar vertebrae on the left,with the degree of injury of 11 lumbar vertebrae in grade 0,16 lumbar vertebrae in grade 1,41 lumbar vertebrae in grade 2,17 lumbar vertebrae in grade 3 and 2 lumbar vertebrae in grade 4 respectively,and 54 lumbar vertebrae on the right,with the degree of injury of 13 lumbar vertebrae in grade0,20 lumbar vertebrae in grade 1,13 lumbar vertebrae in grade 2,24 lumbar vertebrae in grade 3 and 1 lumbar vertebrae in grade 4 respectively.The results of rank test showed that there was significant difference in the degree of articular process injury between the groups diagnosed as lumbar disc herniation and lumbar spinal stenosis.There was significant difference in the degree of articular process injury between different surgical segments.There were also significant differences in the degree of injury between the left and right facet joints in different surgical sites.The results of multiple Logic regression showed that the diagnosis type and surgical segment were the main factors that affected the degree of articular process injury.Conclusion 1.The anatomical structure of the lumbar spine is an organic whole,and deepening the overall understanding of the anatomy of the lumbar spine can help avoid intraoperative disorientation.From L3 to L5,the Angle between the two sides of the lamina gradually increases,the lateral width of the lamina gradually increases,the facet joint gradually changes from sagittal to coronal,and the descending degree of the lamina gradually decreases.Understanding the segmental changes in the anatomy of the lumbar spine can help with the smooth operation,the determination of the extent of lamina removal,the protection of facet joints,and the location of the disc.2.UBE operation has the advantages of less trauma and flexible operation,but it will still cause different degrees of facet joint injuries.The main influencing factors of facet joint injuries are the diagnosis types of lumbar diseases and the surgical segments of lumbar vertebrae.