The Characteristics And Correlation Of Spinopelvic Sagittal Parameters In L4 Degenerative Spondylolisthesis

ObjectiveTo investigate the characteristics and correlation of spinopelvic sagittal parameters in patients with L4 degenerative spondylolisthesis(DS).[Methods] From January 2011 to June 2014,a total of 44 patients with L4 DS and 41 asymptomatic volunteers were enrolled.The spinopelvic sagittal parameters including pelvic incidence(PI),pelvic tilt(PT),sacral slope(SS),lumbar lordosis(LL),sagittal vertical axis(SVA)and T1 pelvic angle(TPA)were measured in standard lateral spine radiographs.All cases were stratified according to the PI value and Roussouly classification for the lumbar lordosis curvature.ResultsCompared with the normal group,L4 DS group showed significantly greater PI,PT and smaller SS.The LL,SVA and TPA showed no significant difference between the two groups.In DS patients,the PT and TPA were significantly higher,but SS were significantly lower in the normal PI group than in the NC and large PI group(P<0.05).According to the Roussouly classification,the distribution of NC group was: 9.8% type 1,56.1% type 2,26.8% type 3 and 7.3% type 4;while the DS group was: 4.5% type 1,25% type 2,43.2% type 3 and 27.3% type 4.Additionally,PI was correlated well with the PT and SS in both groups(P<0.05).TPA had a significant correlation with PI,PT,LL and SVA(P<0.05).ConclusionPelvic incidence was higher in patients with L4 DS than the normal population.Retroverted pelvic contribute to the compensatory mechanism.The T1 pelvic angle was a useful parameter for evaluating the global sagittal spine balance in DS patients.