无症状中国年轻人颈椎矢状位曲度正常值及其与全脊柱平衡的关系

Normative values of cervical sagittal alignment according to the whole spine balance:Based on 126 asymptomatic Chinese young adults

目的:探讨无症状中国年轻人颈椎矢状位曲度的正常值及其与全脊柱平衡的关系。方法:2011年11月—2014年12月招募并选择年龄18~30岁的志愿者行全脊柱侧位X线检查,在X线片上测量指标包括C_(0)-C_(2)角、从C_(2)-C_(3)到C_(6)-C_(7)的间盘角、从C_(3)到C_(7)的椎体角、T_(1)倾斜角、胸椎后凸角(thoracic kyphosis,TK)、腰椎前凸角(lumbar lordosis,LL)、骨盆入射角(pelvic incidence,PI)、骶骨倾斜角(sacral slope,SS)、C_(2)-C_(7)矢状轴向垂线(C_(2)-C_(7)sagittal vertical axis,C_(2)-C_(7)SVA)、头重心至C_(7)的矢状位轴向垂线(center of gravity of head to C_(7)SVA,CGH-C_(7)SVA)、C_(7)到S 1的矢状位轴向垂线(C_(7)-S 1SVA)。依据脊柱骨盆矢状位形态进行Roussouly分型,比较不同Roussouly分型下的颈椎曲度及形态。结果:共纳入126名志愿者参与研究,其中男性67名,女性59名,平均年龄(21.4±2.3)岁。C_(0)-C_(7)前凸角平均为26.0°±12.8°,其中C_(0)-C_(2)前凸角平均为15.2°±6.7°,C_(2)-C_(3)到C_(6)-C_(7)间盘前凸角总和平均为9.1°±12.1°,C_(3)到C_(7)的椎体前凸角总和平均仅为1.4°±10.2°。C_(2)-C_(7)SVA(18.6±7.9)mm和CGH-C_(7)SVA[(22.9±12.3)mm]由C_(7)-S 1SVA[(-21.6±31.0)mm]完美代偿。不同的Roussouly分型间颈椎曲度差异有统计学意义(P<0.01)。颈椎曲度与T_(1)倾斜角(P<0.01)、胸椎后凸角(P<0.01)有显着相关性。从T_(1)倾斜角到C_(0)-C_(2)角,相邻节段间盘角之间存在显著相关性(P<0.05)。结论:测量并计算了无症状中国年轻人颈椎椎体角和间盘角的正常值,发现颈椎前凸主要发生在C_(0)-C_(2)和椎间盘水平,这些角度受到其他脊柱部位形态(T_(1)倾斜角、胸椎后凸角和Roussouly分型)的影响,且相邻间盘角之间存在显著的相关性。

Objective:To explore the normal distribution of cervical sagittal alignment and the relationship between cervical alignment and global spine balance in asymptomatic young adults.Methods:A cohort of 272 asymptomatic Chinese adults(including 161 males and 111 females,with an average age of(23.2±4.4)years,ranging from 18 to 45 years)were prospectively recruited from November 2011 to December 2014.The C_(0)-C_(2)angle,disk angles from C_(2)-C_(3)to C_(6)-C_(7),vertebral angles from C_(3)to C_(7),T_(1)slope,thoracic kyphosis(TK),lumbar lordosis(LL),pelvic incidence(PI),sacral slope(SS),C_(2)-C_(7)sagittal vertical axis(C_(2)-C_(7)SVA),center of gravity of head to C_(7)SVA(CGH-C_(7)SVA),C_(7)-S 1SVA were measured and statistically analyzed.All the subjects were categorized with the Roussouly classification and the cervical morphologies were evaluated as lordotic,straight,sigmoid or kyphotic.Spinal sagittal alignment parameters were compared between different sexes and Roussouly classifications with independent student t test,analysis of variance(ANOVA)or Chi-square test.Correlations between cervical sagittal alignment and global spine sagittal alignment were calculated using the Pearson and Spearman correlation coefficient.Linear regression analysis was performed.Results:Sixty-seven males and 59 females aged from 18 to 30 years old were included in the study.The mean value of C_(0)-C_(7)was 26.0°±12.8°,composed of 15.2°±6.7°for C_(0)-C_(2),9.1°±12.1°for sum of disk angles from C_(2)-C_(3)to C_(6)-C_(7),and 1.4°±10.2°for sum of vertebral angles from C_(3)to C_(7).C_(2)-C_(7)SVA[(18.6±7.9)mm]and CGH-C_(7)SVA[(22.9±12.3)mm]were offset ideally by C_(7)-S 1SVA[(-21.6±31.0)mm].Males had a larger T_(1)slope(P<0.05)and accordingly,a larger cervical lordosis C_(2)-C_(7)(P<0.01)and C_(0)-C_(7)angle(P<0.01)than females.Males had a smaller C_(7)-S 1SVA(P<0.01)and accordingly,a smaller CGH-C_(7)SVA(P=0.165)than females.Significant difference was found between cervical alignment of different Roussouly types(P<0.01).In general,a larger LL was consistent with a set of larger TK,C_(2)-C_(7)angle,C_(0)-C_(7)angle,and vice versa.There was no significant correlation between cervical morphology and the Roussouly classification(Chi-square=10.548,P=0.308).There was significant correlation between cervical alignment and T_(1)slope(P<0.01),TK(P<0.01).There was significant correlation between adjacent segmental angles from T_(1)slope up to C_(0)-C_(2)angle(P<0.05).Conclusion:Normative values of each vertebral angle and disk angle were established.The cervical lordosis occurred mainly at C_(0)-C_(2)and disk levels,which was influenced by parameters of other parts of the spine,such as T_(1)slope,TK and the Roussouly classification.There was significant correlation between adjacent disk angles.