Comparative Study On The Imaging Parameters Of Intervertebral Foramina In Patients With Degenerative Lumbar Spondylolisthesis

Background:Degenerative lumbar spondylolisthesis（DLS）is the most common type of spondylolisthesis,and its occurrence and development are inevitably accompanied by intervertebral slippage,intervertebral foramen morphological changes and so on.At present,there are few literatures to compare and analyze the imaging differences of intervertebral foramen between normal people and DLS patients before and after operation.Based on computed tomography（CT）,it is necessary to further explore the characteristics of intervertebral foramen imaging parameters of DLS patients,the changes before and after operation,and compare them with the relevant parameters of normal population.Objectives:To compare and study the differences of imaging parameters of bilateral intervertebral foramen between normal people and DLS patients of different genders.To analyze and evaluate the changes of anatomical parameters of intervertebral foramen in DLS patients before and after operation.To analyze the influencing factors of lumbar intervertebral foramen area by multivariate linear regression and to provide suggestions for the diagnosis and treatment of lumbar intervertebral foramen stenosis.Methods:80 DLS patients treated in our hospital from September 2017 to June2020 were selected as the case group,40 males and 40 females with complete imaging data.All patients were L4-L5 single segment spondylolisthesis（L4 anterior spondylolisthesis）and had posterior lumbar interbody fusion（PLIF）.In the case group,males were 41-75years old,with an average of 56.22±8.62 years old;females were 39-78years old,with an average of 58.90±9.66 years old.In the same period,120 healthy adults of the same age group were selected as the control group,60 males and 60 females underwent lumbar or abdominal CT.In the control group,males were 41-72 years old,with an average of56.13±7.75 years old;females were 42-76 years old,the average age was58.73±7.43 years.According to the CT imaging data of lumbar vertebrae or abdomen,the minimum cross section of lumbar intervertebral foramen was selected along the direction of L4 pedicle.Upper anteroposterior diameter（UAD）,Lower anteroposterior diameter（LAD）and Longitudinal diameter（LD）of lumbar intervertebral foramen were measured,and the mean values of UAD and LAD were taken as Mean anteroposterior diameter（MAD）.Intervertebral foramen area（IFA）was measured by Image J software.Along the median sagittal diameter of L4 vertebral body,the distance from the posterior edge of L4 vertebral body to L5 vertebral body,the distance from the anterior edge of L5 vertebral body to L4 vertebral body and the midline distance between them were measured,and the mean value was taken as Mean disc height（MDH）.The imaging parameters of lumbar intervertebral foramen in control group and case group were analyzed by nonparametric rank sum test,and the area of lumbar intervertebral foramen was analyzed by multivariate linear regression analysis.Results:UAD,LAD,MAD,LD,IFA and MDH in control group were11.63±1.28mm,16.31±1.43mm,13.97±1.15mm,19.66±1.44mm,164.91±15.51mm²and 11.74±1.22mm;The above parameters before operation in case group were 15.44±2.15mm,10.65±2.73mm,13.04±1.59mm,15.85±2.03mm,131.23±15.04mm²and 7.27±2.18mm;The above parameters after operation in case group were 11.71±1.82mm,13.89±2.29mm,12.80±1.42mm,19.18±2.22mm,167.96±16.88mm²and12.03±1.46mm.After statistical analysis,UAD,LAD,MAD,LD and IFA of the same sex in control group had no statistical significance（P>0.05）.There was no significant difference in UAD,LAD,MAD,IFA and MDH between male and female in control group（P>0.05）,but LD of male was slightly larger than LD of female and showed statistical significance（P<0.05）.Compared with the control group,UAD in the case group increased before operation,while LAD,MAD,LD,IFA and MDH decreased significantly（P<0.05）.UAD,LD,IFA and MDH in the case group can be effectively recovered after operation,and there was no statistical significance compared with the control group（P>0.05）,but there was still a statistical difference despite the increase of LAD,which made MAD statistically significant（p<0.05）;PLIF reduced UAD and increased LAD,which made MAD not statistically significant before and after operation（P>0.05）.In addition,the regression equation Y=12.060+1.663X₁+3.242X₂+3.968X₃（Y is IFA,X₁,X₂and X₃are UAD,LAD and LD）was obtained after multivariate linear regression analysis of IFA,and the model test showed that this equation was statistically significant（P<0.001）.Conclusions:The lumbar intervertebral foramina imaging parameters of normal people have no obvious gender and side differences,while the LD of male was slightly higher than that of female.The lumbar intervertebral foraminal imaging parameters and MDH of DLS patients have obvious changes compared with the normal people,and PLIF can effectively recover UAD,LD,IFA and MDH.The multivariate linear regression analysis showed that IFA was positively correlated with UAD,LAD and LD,and the impact of LD was significant.