| Objective To analyze the correlation between spinopelvic sagittal parameters and the occurrence of adjacent segmental disease after posterior lumbar interbody fusion by comparing the differences in spinopelvic sagittal parameters before posterior lumbar interbody fusion surgery with those at the last follow-up.Methods The cases admitted to General Hospital of Ningxia Medical University and Yinchuan Guolong Orthopedic Hospital from 2017.01-2022.04 who underwent a second lumbar spine surgery for Lumbar adjacent segment disease(LASDis)after posterior lumbar interbody fusion were collected as the LASDis group,with a total of 36 cases.Cases without adjacent segment disease after posterior lumbar interbody fusion with the same follow-up time,age,BMI,sex,and operative segment were selected by a 1:2 ratio as the F-LASDis group,with a total of 72 cases.The spinopelvic sagittal parameters,including sagittal vertical axis(SVA),lumbar lordosis(LL),high lumbar lordosislow(HLL),lumbar lordosis(LLL),and lumbar lordosis of the operated segment,were measured on lateral whole spine radiographs in standing position before and after the initial surgery and at the last follow-up,segmental lumbar lordosis(SLL),pelvic incidence(PI),pelvic tilt(PT),sacral slope(SS),sagittal vertical axis(SVA),etc.The ratio of SLL to LL and LLL to LL was calculated and recorded as the surgical segmental distribution index(RL)and lumbar lordosis distribution index(LDI),respectively.)The clinical data and sagittal parameters of the spinal pelvis were compared and analyzed by statistical methods between the two groups.Results There were no significant differences between the LASDis and F-LASDis groups in age,gender,BMI,follow-up time and initial surgical segment(P>0.05).the number of cases with SVA≥50mm,RL<0.4,LDI<0.6,PT≥20 ° and PI-LL≥10 ° was significantly greater in the LASDis group than in the F-LASDis group(P<0.05).LL and SLL in the LASDis group were significantly smaller than those in the F-LASDis group(P<0.05),and the angle of tilt of adjacent vertebrae on PT and stance in the LASDis group was significantly larger than that in the F-LASDis group(P<0.05).The conditional logistic analysis revealed that SLL was a protective factor for the occurrence of LASDis,and RL<0.4,LDI<0.6,and PI-LL≥10° were independent risk factors for the occurrence of LASDis.Conclusion There is a strong correlation between spinopelvic sagittal parameters and the occurrence of LASDis after lumbar interbody fusion.RL<0.4,LDI<0.6,and PI-LL≥10°are independent risk factors for the occurrence of LASDis after lumbar interbody fusion. |
