Correlation Between Spinopelvic Sagittal Alignment And Lumbar Disc Degeneration

Objectives: A retrospective study to explore the role of spinopelvic sagittal alignment in the development of lumbar disc degeneration(LDD).Methods: Retrospective analysis was conducted on 76 patients with lumbar disc degeneration disease(lumbar disc herniation,degenerative lumbar instability)underwent surgery in our hospital from January 2013 to December 2015.Record and analyze the general condition of the patient.Location ? range and degree of intervertebral disc degeneration are evaluated and graded on T2-weighted magnetic resonance images using the Pfirrmann grading system.Full-length radiographs of the spine were taken to evaluate pelvic incidence(PI),sacral slope(SS),pelvic tilt(PT),thoracic kyphosis(TK),lumbar lordosis(LL),and sagittal vertical axis(SVA).Analyze the correlations between location?range and degree of intervertebral disc degeneration and spinopelvic parameters.Explore the differences in gender and PI size.Results: The mean age of male patients and female patients are 58.86 and 53.28(P?0.05).The value of location?range and degree are 3.74±0.78?3.92±1.07(P?0.05)?2.41±1.36?1.81±1.01(P?0.05)?3.73±0.73?3.38±0.54(P?0.05),respectively.We found a statistically significant correlation(Pearson's bilateral test)between the following values:age and TK(r=0.376,P?0.01)?age and location(r=-0.358,P?0.01),age and range(r=0.329,P?0.01)?age and degree(r=0.452,P?0.01)?TK and LL(r=0.531,P?0.01)?LL and PI(r=0.409,P?0.01);LL and SS(r=0.827,P?0.01)?PI and SS(r=0.0.532,P?0.01)?PI?PT(r=0.711,P?0.01)PI and location(r=-0.257,P?0.05)?SVA and range(r=0.304,P?0.01)?SVA and degree(r=0.353,P?0.01).The value of location in patients with PI>50°is 4.14±0.64,yet value of location in patients with PI?50°is 3.57±1.08(P?0.05).Conclusions: 1.With the degeneration of lumbar disc,the morphology of the spine and pelvis changes constantly to adjust the center of gravity and reduce energy consumption.2.The location?range?degree of lumbar disc degeneration is closely related to age.3.The location of lumbar disc degeneration usually appears in the lower lumbar spine and is correlated with spinopelvic parameter.PI is an important factor causing the different location of lumbar disc degeneration--patients with PI?50°,more likely to occur lumbar disc degeneration from L4/5 to L5/S1 disc,yet patients with PI>50°,more likely to occur lumbar disc degeneration in L3/4?L4/L5 disc.