中文摘要：

目的：研究青少年L5／S1发育不良性滑脱患者的骶骨矢状面形态。方法：回顾性分析2002年5月-2016年3月人院手术治疗的13例青少年L5／S1发育不良性滑脱患者，男2例，女11例，年龄12．2±3．1岁（9～18岁）。以年龄匹配的30例正常青少年为对照组。在站立位全脊柱侧位x线片上测量骶骨形态、姿势等参数。采用独立样木t检验对滑脱组和对照组以及滑脱组内低度发育不良亚组和高度发育不良亚组的各参数进行对比分析。结果：滑脱组患者中，10例存在S1上终板拱顶样改变，6例L5椎体楔形变，9例L5-S1后凸成角畸形。其腰骶角、骶骨平台角和S1指数均显著低于对照组；骶骨形态也异于对照组，骶骨角和S1上角显著小于对照组，骶骨头端（S1）曲度减小，然而骶骨的整体后凸角度显著大于对照组（Cobb法：50．1°±10．6°比18．1°±10．4°；Ferguson法：40．50±9．9。比23．1。±11．50）。滑脱组矢状面平衡显著大于对照组（46．5±42．3mm比-25．6＋21．8mm），且其骨盆入射角、L5入射角、骨盆倾斜角、骨盆矢状面厚度均显著大于对照组（P〈0．01），而骶骨倾斜角却显著小于对照组（P〈0．05）。滑脱组呈现出躯干明显前倾、骨盆后旋、骶骨直立的姿态。滑脱组中高度发育不良8例，低度发育不良5例。高度发育不良组与低度发育不良组相比．其滑脱程度、骶骨后凸角及矢状面轴向垂直距离均显著增大[（67．3±18．6）％比（45．4±12．5）％；45．8°±8．4°比32．2°±5．1°：52．6±24．7mm比21．6±9．5mm（P〈0．05）。结论：青少年L5／S1发育不良性腰椎滑脱患者除腰骶局部发育不良外，骶骨呈明显后凸形态。因躯干前倾，骨盆后旋和骶骨垂直化以代偿矢状面失衡，而这些异常形态受发育不良程度影响。

英文摘要：

Objectives： To evaluate the sagittal morphology ofsacruminadolescents with LS/S1 dysplastic spondylolisthesis. Methods： 13 adolescent patients with L5/S1 dysplastic spondylolisthesis （2 males and 11 females; mean age, 12.2±3.1 years; range, 9 to 18 years） and age-matched control group of 30 normal adolescents were recruited in this retrospective study. All patients received surgical intervention from May 2002 to March 2016 in our hospital. Radiographic measurements including sacral morphology parameters, postura] parameters were carried out on the standing upright lateral radiographs of the spine and pelvis. Independent samples t tests was used to analyze the differences of radiographic parameters. Results： Adolescent patients with LS/S1 dysplastie spondylolisthesis had significant morphologic difference in segmental sacrum morphology and global sacral configuration. There were 10 domed sacrums, 6 wedged L5 vertebral bodys and 9 lumbosaera] kyphosis among 13 dysplastic patients. The sacral angle and S1 superior angle of dysplastic groups were much lower, but both sacral kyphosisin Cobb method （50.1°±10.6° versus 18.1°±10.4°） and in Ferguson method（40.5°±9.9° versus 23.1°±11.5°） were higher than those in control group, which meant that dysp]astic patients characterized with a more vertical S1 vertebrae and much severer global sacral kyphosis. Compare to control group, the lumbosaeral angle, sacral table angleand S1 index of dysplastic group were extremely lower（P〈0.01）. While sagittal vertical axis（46.5＋42.3mm versus -25.6＋21.8mm）, L5 incidence, pelvic tiltand sagittal pelvic thicknessin dysplastic group were significantly higher than those in control group （P〈0.05）, sacral slope were much lower. The dysplastic patients had aabmorlual posture containing trunk forward leaning, pelvic retroversion and vertical sacrum. In comparison with the mild dysplastic spondylolisthesis group（5 cases）, thehigh group（8 eases） were significantly higher on slip percentage[?