青少年L_5/S_1峡部裂性腰椎滑脱患者脊柱-骨盆矢状面形态分析

Analysis of spinopelvic sagittal morphology of adolescent L_5/S_1 isthmic spondylolisthesis

目的探讨青少年L_5/S_1峡部裂性腰椎滑脱患者的脊柱-骨盆矢状面形态改变。方法回顾性分析2009年10月—2017年1月收治的29例青少年L_5/S_1峡部裂性腰椎滑脱患者影像学资料,以30例年龄匹配的正常青少年影像学资料作为对照。在站立位全脊柱侧位X线片上测量滑脱角(SA)、滑脱距离(SD)、骨盆入射角(PI)、骨盆倾斜角(PT)、骶骨倾斜角(SS)、骨盆矢状面厚度(SPT)、L_5入射角(L_5I)、腰椎前凸角(LL)、胸椎后凸角(TK)、脊柱矢状位平衡(SVA)、骶骨平台角(STA)、S_1指数、腰骶角(LSA)等脊柱-骨盆矢状面参数,并计算滑脱率(SP),比较滑脱组与对照组以及低滑脱(SP≤17%)与高滑脱(SP>17%)亚组之间的差异,并采用Pearson相关检验分析SP与各影像学参数的相关性。结果滑脱组SA为-4.5°±9.6°,SD为(7.1±3.6)mm,SP为(22.2±11.1)%。滑脱组的LSA、STA、S_1指数小于对照组,PI、PT、SS、SPT、L_5I、SVA及LL大于对照组,差异均有统计学意义(P<0.05);2组TK差异无统计学意义(P>0.05)。高滑脱亚组的SA、TK、LSA、STA及S_1指数均显著小于低滑脱亚组,PI、PT、SS、SPT、L_5I和SVA均大于低滑脱亚组,差异均有统计学意义(P<0.05);2个亚组的LL差异无统计学意义(P>0.05)。滑脱组PI、PT、SPT、L_5I、LL与SP呈正相关,TK、LSA、STA及S_1指数与SP成负相关,SS、SVA与SP无明显相关性。结论腰骶部先天发育不良可能是青少年峡部裂性腰椎滑脱发生的始动因素。受滑脱程度影响,其脊柱-骨盆矢状面形态显著异常,表现出腰椎前凸增大、躯干前倾,同时骨盆后旋、屈髋屈膝等异常代偿姿势。

Objective To investigate the change of spinopelvic sagittal morphology in adolescent L5/S1 isthmic spondylolisthesis patients. Methods The data of 29 adolescent L5/S1 isthmic spondylolisthesis patients admitted between October 2009 and January 2017 were retrospectively analyzed, and an age-matched control group of 30 normal adolescents were recruited. The spinopelvic sagittal parameters were measured on the standing lateral roentgenograph that spanned from occiput to hip joints. The parameters included slip angle（SA）, slip distance（SD）, slip percentage（SP）, pelvic incidence（PI）, pelvic tilt（PT）, sacral slope （SS）, sagittal pelvic thickness（SPT）, L5 incidence（L5I）, lumbar lordosis（LL）, thoracic kyphosis（TK）, sagittal vertical axis （SVA）, sacral table angle（STA）, S1 index and lumbar-sacral angle（LSA）. The radiographic parameters were compared between spondylolisthesis and control groups, and between low-grade spondylolisthesis（SP ≤ 17%） and high-grade spondylolisthesis （SP 〉 17%） subgroups. Pearson correlation test was used to analyze the relationship between spinopelvic sagittal parameters and SP. Results The SA was -4.5°±9.6°, SD（7.1±3.6）mm, and SP（22.2±11.0）% in spondylolisthesis group. The STA, S1 index and LSA were lower in spondylolisthesis group than in the control group, while PI, PT, SS, SPT, L5I, SVA and LL were higher in spondylolisthesis group than in the control group; and all with statistical significance（P〈0.05）. There was no statistical significance in the difference of TK between the 2 groups（P〉0.05）. The SA, TK, STA, LSA and S1 index in high grade spondylolisthesis subgroup were significantly lower than in the low-grade spondylolisthesis subgroup; the PI, PT, SS, SPT, L5I and SVA in high-grade spondylolisthesis subgroup were significantly higher than in the low-grade spondylolisthesis subgroup; and all with statistical significance（P〈0.05）. There was no statistical significance in the difference of LL between the 2 subgroups（P〉0.05）. In spondylolisthesis group, SP was found to be positively correlated with PI, PT, SPT, L5I and LL; while negatively related with TK, LSA, STA and S1 index. No correlation was found between SP and both SS and SVA. Conclusion Congenital sacral dysplasia may be the initiating factor for adolescent lumbar isthmic spondylolisthesis. Lumbar isthmic spondylolisthesis could lead to significant abnormality of the spinopelvic morphology of the sigittal plane, which presents as increased lumbar lordosis, forward-leaning of the trunk, backward