Sagittal Radiographic Features Of Lumbar Disc Herniation And Spinal Stenosis

Background:With the change of modern people’s life style,the time for people to bend down and sit down is obviously increased.More and more yovung people have symptoms of neck,chest and back pain,weakness,spinal flexion and extension function decline without obvious trauma.Many of them have found that the physiological curvature of cervical spine disappears,even reverses,and the lumbar lordosis straightens.Therefore,more and more scholars pay attention to the study of spine-pelvis composite sagittal balance.There are many reasons for sagittal imbalance of spine and pelvis,including spine fracture,spinal deformity,infection and degenerative diseases.Lumbar degenerative diseases are the most common clinical diseases.Lumbar disc herniation and lumbar spinal stenosis are common degenerative diseases of the lumbar spine.Objective:The purpose of this study was to study the sagittal imaging characteristics of lumbar disc hemiation(LDH)and lumbar spinal stenosis(LSS),to explore the related factors of spinal anteroposterior inclination.Methods:A retrospective study of 206 cases of LDH and LSS hospitalized in our hospital from January 1,2015 to September 10,2016.There were 94 patients with LDH,48 males and 46 females,aged 50.7+ 13.2 years,112 patients with LSS,45 males and 67 females,aged 63.0+7.8 years.Sagittal measurements of the spine and pelvis include:pelvic incidence(PI)、pelvic tih(PT)、sacral slope(SS)、sagittal vertical axis(SVA)、SVA-Location、T1-Spinopelvic inclination(T1-SPi)、T9-Spinopelvic inclination(T9-SPi)、lumbar lordosis(LL)、apex of total lumbar lordosis(LL Apex)、upper end vertebra of lumbar lordosis(LL UEV)、lower end vertebra of lumbar lordosis(LL LEV)、thoracic kyphosis(TK)、apex of total tihoracic kyphosis(TK Apex)、upper end vertebra of thoracic kyphosis(TKUEV)、lower end vertebra of thoracic kyphosis(TK LEV)、thoracolumbar Junction(TLJ).Pearson chi-sqxuare test was used for gender.The other parameters of independent sample t test and non-paraQetric test were compared between the two groups.According to the difference of positive and negative values of SVA,the two disease groups were divided into two subgroups.The same statistical analysis was carried out among the subgroups,and the related factors of SVA were further explored through correlation analysis.Results:The LDH group was younger than LSS group.The sacral tilt in the LSS group was about 3 degrees larger than LDH group,the luabar lordosis was about 7 degrees larger than LDH group.When SVA>0,the SVA of LSS subgroup was 15 mm smaller than LDH subgroup,the T1SP was 1.4 degrees smaller,the SS was 3.5 degrees larger,the absolute value of LL was 7 degrees larger,and the TK Apex was 1 segment higher.There was no difference between LSS and LDH subgroup whenSVA<0.We use related analysis to analyze the factors that affect SVA.In the LDH and LSS subgroups,SVA was positively correlated with TISP,T9SP,TK Apex,age,PT and PI,negatively correlated with LL Apex and LL LEV,when SVA≧0.In the LDH subgroup,SVA was positively correlated with TISP,T9SP,when SVA<0.In the LSS subgroup,SVA was positively correlated with TISP,when SVA<0.Conclusion:Compared with the LSS group,patients with LDH had smaller thoracic kyphosis,smaller lumbar lordosis and straighter trunk.When SVA≧0,the related factors of SVA in LSS and LDH subgroups were TISP,T9SP,age,PT,PI,LL Apex,LL LEV;when SVA<0,the related factors of SVA in LDH subgroup were TISP,T9SP,and the related factors of SVA in LSS subgroup were only T1SP.