To Explore The Measurement Of The Lumbar Lamina Angle And Its Relationship With Lumbar Spinal Stenosis

Purpose:As a common disease in clinical work,lumbar spinal stenosis(LSS)often occurs in the elderly.The patients always suffer from typical symptoms including pain and numbness in the lumbar and lower extremities and intermittent claudication,which causes more obvious impact on their daily life.So far,most scholars have been consistent with the application of transverse diameter,median sagittal diameter of vertebral canal and sagittal diameter of lateral recess as main imaging diagnostic basis of LSS,while the parameter of lumbar lamina angle(LLA)has not been yet extensively used in the diagnosis of LSS.With the measurement and further statistical analysis of transverse diameter,median sagittal diameter of spinal canal and bilateral LLAs,we aimed at exploring whether there were statistical differences between the LLA values in central LSS patients and that in normal ones.We were also curious about whether there was any correlation between transverse diameter or median sagittal diameter of spinal canal and LLAs,as well as the relationship between the ratio of transverse diameter with median sagittal diameter(MSD/TD ratio)and LLAs.The conclusions we drew would offer a new diagnostic reference index of central LSS and a new thinking in diagnosis and treatment in LSS patients.Methods:Our research group retrospectively collected parameters of 100 cases(Among those 100 cases,there were 52 cases of male and 48 cases of female)who seek medical advices and did lumbar magnetic resonance imaging(MRI)examinations between July,2017 and March,2020.All the cases were divided into LSS group(experimental group)and non-LSS group(control)according to the situation whether there was any central LSS in each lumbar intervertebral space(L1/2,L2/3,L3/4,L4/5,L5/S1).Moreover,the LSS group was further divided into two groups namely median sagittal diameter stenosis group(MSD group)and transverse diameter stenosis group(TD group).In-hospital data including age,sex,and admission number as well as lumbar MRI images were collected for further data processing.Digimizer software was applied to measure the minimum median sagittal diameter,transverse diameter and bilateral LLA values of each intervertebral space in all the cases.SPSS 20.0 software was applied to do statistical analysis.Average median sagittal diameter,transverse diameter and bilateral LLA values were calculated in each group,while homogeneity of variance test and independent-sample t test were used to verify whether there was statistical differences between bilateral LLAs and among LLA values in the four groups.With the help of Pearson correlation analysis of continuous variables,we verified whether there was any correlation between median sagittal diameter of lumbar canal and LLAs,transverse diameter of lumbar canal and LLAs,as well as LLAs and MSD/TD ratio.Result:100 cases were brought into our research,and there were 52 male cases and 48 female cases with an average age at 52.94112.96 years old.The bilateral LLA values from each intervertebral space were processed with homogeneity of variance test.It was shown that all the P values were greater than 0.05,which verified the homogeneity of variance.Moreover,the results of t test verified that there were no statistical differences between the bilateral LLAs with all the P values greater than 0.05.It was verified that there were statistical differences between the LLAs in central LSS group and control group with t test,while the same results came out between the MSD group and control group,with P values smaller than 0.05.The t test results of LLAs between TD group and control group showed that there were statistical differences in all the intervertebral spaces with P values smaller than 0.05,except L3/4.There were no statistical differences between LLAs in MSD group and TD group with P values greater than 0.05 in all intervertebral spaces except L2/3 and L4/5.It was verified by Pearson correlation analysis that there was a positive correlation relationship between left or right side LLAs and median sagittal diameters of spinal canal in each intervertebral space with P values smaller than 0.05.Similar conclusions were found in the correlation analysis of bilateral LLAs and MSD/TD ratios with P values smaller than 0.05 except in L5/S1 intervertebral space.However,it was found that there was no significant correlation between left or right side LLAs and transverse diameter of spinal canal with P values greater than 0.05 except in L1/2 and L3/4 intervertebral spaces.Conclusion:It was shown in our research that there were significant statistical differences of LLAs among central LSS patients and normal ones.While there was a strong correlation between LLA and median sagittal diameter of spinal canal.Similar correlation relationships were found between LLA and MSD/TD ratio in multiple lumbar intervertebral spaces except L5/S1.Such results showed that LLA could reflect the morphological characteristics of spinal canal and the degree of median spinal stenosis to a certain extent.Moreover,compared to other parameters,the measurement processes of LLA were easier to practice and it would be easier to be accomplished in clinical work.Therefore,the measurement of LLA supplied a new thinking in imaging diagnosis of central LSS.It could also bring more aids to the diagnosis and treatment of LSS.