Analysis Of Lumbar Intervertebral Height Index,intervertebral Angle And Lumbar Lordosis Angle In Normal Population And Study On The Relationship Between Intervertebral Height Index And Pfirrmann Classification

With the aging of the population in China,the lumbar spine degeneration disease has become an important problem effectting the quality of life especial for aged population.In the study of lumbar spine degeneration disease,Scholars had paid more attention to disc degeneration.Although they have studied the changes of pathophysiology in lumbar intervertebral disc degeneration,but there is still controversy exist over the criteria for determining the degree of degeneration.Most scholars have adopted the image evaluation criteria for proposed by Pfirrmann in 2001.The method divides the intervertebral disc into5 levels mainly according to the height of the intervertebral space,the signal of the intervertebral disc,and the shape of the intervertebral disc.Among them,the height of the intervertebral space is the most important criterion for imaging.Lumbar fusion operation is commonly used in the treatment of lumbar degenerative disease and recover normal intervertebral height can improve the efficacy after operation and reduce postoperative adjacent segment degeneration（ASD）occurs.After the prediction formula of LL:LL=PI+9 is introduced,it is widely used in clinical work.However,with the further research,Scholars found that there is a significant difference between Chinese normal population and the western population.The normal PI and LL values of Chinese normal people are significantly smaller than those of the western population,and it also found that the relationship between PI and LL is changing with age.So,this formula is not suitable for Chinese people.And it is found that the relationship between PI and LL is also changing with age.However,due to the lack of large sample data of normal population,it is difficult to treatment according to the normal data in clinical.In the process of studying normal lumbar intervertebral height index,we found that Pfirrmann classification was lacking of quantitative standard,existing certain error.For this reason,we try to analyze the relationship between the lumbar intervertebral height index（IHI）and the Pfirrmann grading system and establish a regression formula to improve the system at lacking of quantitative evaluation in intervertebral disc height.The specific contents of this article are as follows:The first part.Analysis of lumbar intervertebral height index,intervertebral angle and lumbar lordosis angle in normal imaging populationObjectivesThis study is aimed at measuring the intervertebral height index（IHI）,intervertebral angle（IVA）in every lumbar segment and lumbar lordosis（LL）in normal imaging population,and analyzing its characteristics.MethodsCollecting outpatients from January 2014 to October 2016 in**hospital department of orthopedics.ALL of them underwent standard lateral X-ray,lumbar MRI and show no obvious disease and Pfirrmann Scale changes（P-c）were less than or equal to II grade.According to the inclusion criteria,a total of 303 people,including 144 male and 159female left.Divided into five groups according to age:young group（20-29 years old,56cases）;young and middle aged group（30-39 years old,59 cases）;middle aged group（40-49 years old,83 cases）;middle aged and aged group（50-59 years old,57 cases）;aged group（over 60 years,48 cases）.Two experienced spine surgeons using Surgimap software to get the following parameters in lateral radiographs:IHI,IVA in every lumbar segment and LL.Analyzing the changes of IHI,IVA and LL in different age,gender and P-c groups.ResultsThis study get total 303 case IHI,IVA in every lumbar segment and LL.IHI in different lumbar segment was:L1-2:22.98±3.2;L2-3:26.32±3.3;L3-4:29.09±3.2;L4-5:32.26±3.4;L5-1:34.02±4.7.The IHI is gradually increased from L1-2 to L5-S1,and it’s statistically significant（P<0.05）.L5-S1 segment has reached maximum.Comparing the different in different age,gender and P-G groups in the same segment,there is difference in IHI,but no statistical significance（P>0.05）.IVA in different lumbar segment and LL was:L1-2:4.08±2.4;L2-3:5.98±2.9;L3-4:7.49±3.1;L4-5:9.55±3.8;L5-1:13.72.±4.8;LL:39.42±14.5.The IVA is gradually increased from L1-2 to L5-S1 and it’s statistically significant（P<0.05）.Comparing the different age groups,there is significance difference（P<0.05）in IHI at L2-3,L3-4,L4-5 segments and LL,but no statistical significance in L1-2,L5-S1 segments（P>0.05）.ConclusionThis study got the normal range of IHI,IVA in every lumbar segments and LL in normal imaging population.At no degenerative grade degeneration disc,the lumbar spine IHI remained unchanged and did not vary with age or gender.The changes of IVA and LL in each segment of the lumbar spine varied with age.After entering the middle-aged group,the angle gradually increased with age.The second part.The relationship between intervertebral disc height index and Pfirrmann-classification of lumbar intervertebral discPurpose:To analyze the correlation between the lumbar intervertebral height index（IHI）and the Pfirrmann-classification system and establish a regression formula to improve the system at lacking of quantitative evaluation in intervertebral disc height.Method:From January 2015 to December 2015,600 patients who underwent lumbar spine surgery in**hospital were collected.According to the inclusion criteria,a total of 213patients were incorporated into the group.Among them,110 were male and 103 were female.Age distributed from 21 years to 81 years old.ALL of them had standard lateral X-ray film and lumbar spine MRI examine.3 experienced physicians measured lumbar height index(IHI_4-5)and lumbar 4-5 segments Pfirrmann-classification（P-c）in lateral X-ray film and MRI examine respectively.Investigating the correlation between the IHI_4-5and the P-G,analyzing and establishing a linear regression fitting formula.Results:The ICC was greater than 0.85 in the group and between groups.Pfirrmann-classification distribution were:grade I:15 cases,grade II:68 cases,grade III:72 cases,grade IV:37 cases,grade V:21 cases.The different Pfirrmann grade’s IHI_4-5were:grade I:34.04±4.3,grade II:32.40±3,grade III:28.89±2.9,grade IV:24.04±2.6,grade V:21.68±4.IHI4-5 in different grades of Pfirrmann and different gender is:male:I:33.07+5+3.3;II:32.22;III:28.90+3;IV:23.78+2.3,V:22.03+3.9;female:I:35.14+3.4;II:32.58+2.6 III;grade:28.88+2.9;IV:24.28+2.9,V:21.29+5.There was no significant difference in IHI4-5 between different genders（P>0.05）.The difference between I and II was not statistically significant（P>0.05）.From grade II to grade V,the IHI_4-5 was gradually decreased,and the difference was statistically significant（p<0.05）.IHI_4-5 was significantly related to Pfirrmann grade（r=0.77,p<0.01）.A preliminary regression formula between IHI4-5 and Pfirrmann was:P-c=10.54-0.263×IHI_4-5.（Adjusted R²=0.603,P<0.01）Conclusion:Lumbar intervertebral disc height in_-d_-ex and Pfirrmann classification has certain correlation,regular Pfirrmann grade assessment lack of quantitative standard for disc high,the regression formula is useful for the clinical work to assessment disc degeneration more accurately.