Lumbar vertebral endplate sagittal morphology of patients with lumbar disc herniation

English Keywords:Lumbar disc herniation  Endplate  Endplate morphology  Lumbar degeneration

English Abstract:

  【Abstract】 Objectives: To investigate the lower lumbar spine(L3-S1) sagittal endplate morphology of lumbar disc herniation(LDH) patients. Methods: A retrospective analysis was performed on patients with lumbar disc herniation and volunteers treated in our hospital from June 2016 to July 2017. A total of 141 patients with LDH were enrolled, including 61 males and 80 females, with an average age of 61.6±10.1(41-79) years and an average BMI of 26.3±3.4(18.3-33.2). The control group included 109 volunteers, including 47 males and 62 females, with an average age of 55.4±12.2(40-87) years and an average BMI of 25.3±3.6(17.6-32.5). Endplate morphological parameters from L3 inferior endplate to S1 superior endplate in LDH patients and control volunteers were measured on mid-sagittal CT reconstruction. Morphology parameters included endplate concavity depth(ECD), sagittal concavity angle(SCA) and endplate concavity apex(ECA). Degeneration of intervertebral discs were evaluated by using Pfirrmann classification on MRI image. Endplates of volunteers were used as control. The t-test was used to compare the sagittal endplate morphological parameters between the LDH group and the control group. Endplate morphology parameters of both LDH patients and control volunteers were grouped according to the degree of disc degeneration(Pfirrmann Ⅱ to Pfirrmann Ⅴ). Kruskal-Wallis test was used to compare the endplate morphology among different groups. Results: The ECD of each segment of LDH group was significantly lower than that of the control group(P=0.016 at L4 superior endplate; P<0.01 at the remaining endplates). The endplate SCA of each segment of LDH group was significantly greater than that of the control group(P<0.01). There were no statistically significant differences of ECA in all segmental endplates except for the L3 inferior endplate(P=0.014). Comparison of Pfirrmann Ⅲ and Ⅳ discs in the L4/5 and L5/S1 segments showed that the ECD of endplates in LDH group was significantly smaller than that of the control group(P<0.05) and there was no significant difference between the groups in the ECA(P>0.05). The results of Kruskal-Wallis test showed that with the progression of intervertebral disc degeneration, the ECD of each segment decreased(P<0.01), the SCA increased(P<0.01), and ECA showed no consistent trend between groups. Conclusions: The results of the present study show that endplates of LDH patients are less concaved compared to those of the controls. Lower degree of endplate concavity corresponds to high degree of intervertebral disc degeneration.