腰椎滑脱合并上段腰椎后滑脱的矢状面形态分析

Sagittal alignment of lumbar spondylolisthesis:radiological evaluation and factors related to retrolisthesis

[目的]研究腰椎滑脱合并后滑脱脊柱-骨盆矢状面形态特征,探讨腰椎后滑脱的原因。[方法]回顾性分析2012年1月~2013年12月55例有完整影像学资料的腰椎滑脱患者,其中腰椎前向滑脱合并后向滑脱19例（后滑脱组）,男8例,女11例;平均年龄59.6（51~69）岁;前向腰椎滑脱36例（无后滑脱组）,男22例,女14例;平均年龄53.6（30~69）岁。对两组患者脊柱骨盆矢状面形态学参数进行测量：腰椎前凸（lumber lordosis,LL）、胸椎后凸（thoracic kyphosis,TK）、矢状面轴向垂直距离（sagittal vertical axis,SVA）、骨盆入射角（pelvic incidence,PI）、骨盆倾斜角（pelvic tilt,PT）、骶骨倾斜角（sacral slop,SS）、胸腰段交界后凸（thoracolumbar junction,TLJ）、前滑脱椎体滑脱率及分度。采用独立样本t检验对两组患者的上述指标进行比较。[结果]后滑脱组患者T10~L2后凸角及年龄分别为（16.2±8.5）°、（59.5±5.3）岁,明显高于无后滑脱组的（3.4±5.5）°、（50.5±9.2）岁（P〈0.05）,两组患者的骨盆参数PI[无后滑脱组（55.5±9.6）°,后滑脱组（52.0±13.1）°]、PT（16.1±5.5°,18.1±13.0°）、SS（39.3±7.2°,38.3±7.0°）、LL（53.9±8.6°,53.5±15.5°）、TK（30.4±9.6°,33.3±11.9°）、SVA（30.2±45.2 mm,33.9±26.5 mm）及椎体滑脱率（21.8±9.6%,15.3±8.1%）之间差异无统计学意义（P〉0.05）。[结论]后滑脱的发生提示患者矢状面代偿能力不足或已达到失代偿,而PI较小、TLJ增大及高龄可能是腰椎滑脱患者合并椎体后向滑移的重要危险因素。

[ Objectivel To investigate the role of sagittal spino - pelvic alignment in the pathogenesis of lumbar retrolisthe- sis. [Methods] From January 2012 to December 2013, 19 patients （8 males and 11 females with an average age of 59.6 years） treated at our department for lumbar retrolisthesis accompanied by anterolisthesis were retrospectively reviewed. Thirty - six patients with lumbar anterolisthesis alone （22 males, 14 females; mean age 53.6 years） were selected to serve as the control group. The following parameters were evaluated on standing upright lateral radiographs and compared between the two groups u- sing the student t test： lumbar lordosis, thoracic kyphosis, sagittal vertical axis, pelvic incidence, pelvic tilt, sacral slope, tho- raeolumbar junctional angle, and slip grade. [ Results ] Gender did not differ between the groups, whereas patients with both retrolisthesis and anterolisthesis were found to be significantly older than those with anterolisthesis alone （59. 5 vs. 50. 5 years, P 〈 0. 05） . Regarding the sagittal spinopelvic parameters, no statistical differences were noted between the two groups except for the thoracolumar junctional （TLJ） angle which was significantly larger in the retrolisthesis group （ 16. 2± 8.5° vs. 3.4 ± 5.5 ° , P 〈 0. 05 ） . Additionally, Pearson test revealed a significant correlation between the TJL and slip grade （ r = 0. 664, P = 0. 002） . [ Conclusion ] Lumbar retrolisthesis acts as a compensatory mechanism in maintaining the sagittal balance by mov- ing the gravity axis posteriorly. Older patients with larger thoracolumbar junctional angle are at increased risk for the development of lumbar retrolisthesis.