L4/5单节段融合对不同腰椎Roussouly分型腰椎骨盆矢状位参数和临床疗效的影响

The clinical efficacy of lumbar L4/5 single level fusion and its effect on the lumbar-pelvis sagittal alignment parameters of differrent Roussouly type

目的：探讨腰椎单节段（L4/5）融合对不同腰椎Roussouly分型腰椎骨盆矢状位参数和临床疗效的影响.方法：回顾我院2008年3月～2012年3月行L4/5节段融合的患者317例,共纳入具有健康相邻节段、随访≥3年、资料齐全者51例.男25例,女26例,平均年龄43.45岁.依据腰椎前凸顶点位置将腰椎矢状位曲线分为四型（Roussouly分型）：Ⅰ型,顶点位于L5椎体或者L4/5椎间隙;Ⅱ型,顶点位于L4底部或者中部;Ⅲ型,顶点位于L4上部或者L3/4椎间隙;Ⅳ型,顶点位于L3椎体及其以上.术前、术后和末次随访时行视觉模拟评分（VAS）、Oswestry功能障碍指数（ODI）、JOA评分,测量腰椎前凸角（LL）、上半圆（UP arc）、L4/5椎间前凸角（I-VA4-5）、骨盆入射角（PI）、骨盆倾斜角（PT）、骶骨倾斜角（SS）、C7垂线骶骨距离/股骨头骶骨距离比值（C7PL/SFD ratio）,术前相邻节段评估应用MRI Modified Pfirrmann Scale（Modic）量表分析,随访应用UCLA量表结合脊柱退变稳定性标准评估影像学相邻节段退变（rASD）情况.结果：本组腰椎Roussouly分型的分布如下：Ⅰ型10例（19.61％）,Ⅱ型15例（29.42％）,Ⅲ型20例（39.22％）,Ⅳ型6例（11.76％）.平均随访42.58个月（36～67个月）.Ⅰ型：术后和末次随访时的LL、UP arc、和SS较术前显著提高,PT减小,具有统计学差异（P＜0.01）.Ⅱ和Ⅲ型：LL末次随访时较术前显著提高（P＜0.05）,而SS、PT、PI无显著性变化,Ⅱ型末次随访时UParc较术前和术后显著提高.Ⅳ型：LL、UP arc、SS、PT和PI手术前和术后对比无显著性差异.各型术后及随访时的IVA4-5较术前提高,而C7PL/SFD比值减小,各型术后及末次随访时的VAS、ODI和JOA评分与术前相比显著改善.本组病例中rASD发病率为17.64％,rASD相关危险因素分析发现：年龄、随访时间、IVA4-5、PI是显著危险因素.结论：单节段融合可显著增加节段前凸角,但在不同腰椎Roussouly分型中对脊柱-骨盆参数的影响有所不同.节段椎间角度是ASD的显著危险因素,年龄越大,随访时间越长,PI值较高时较容易发生rASD.

Objectives：To investigate the effect of single L4/5 fasion（SL4/5） on the lumbar-pelvis sagittal alignment parameters of differrent Roussouly type and its clinical efficacy.Methods：Between March 2008 and March 2012,317 patients with lumbar fusion of SL4/5 were collected,and 51 cases of them（with healthy adjacent segments,complete follow-up data,follow-up time ≥3 years） included in this study,25 males and 26 females,with an average age of 43.45 years.They were categorized into 4 types on the basis of lumbar lordosis of lumbar sagittal vertex position curve（Roussouly type）：Type Ⅰ,vertex located in L5 vertebral body or L4/5 intervertebral space; Type Ⅱ,vertex located at the bottom or middle of the L4; Type Ⅲ,vertex located at the upper part of L4 or L3/4 intervertebral space; Type Ⅳ,vertex located at the L3 vertebral body and above.The VAS,ODI and JOA scores were compared,and the lumbar-pelvic parameters were measured,such as pelvic incidence（PI）,sacral slope（SS）,pelvic tilt（PT）,lumbar lordosis（LL）,UP arc and intervertebral lordosis of lumbar 4-5（IVA4-5）,C7 plumb line/Sacro-femoral distance ratio（C7PL/SFD ratio） at the preopera tion,postoperation and final follow-up.MRI was adopted to evaluate radiographic adjacent segment degeneration （rASD） before the operation,and the UCLA Grading Scale and intervertebral stability criteria of lumbar degeneration were introduced to evaluate rASD after the operation.Changes of the parameters in different periods were statistically analyzed.Results：The mean follow-up time was 42.58 months（36 to 67 months）.The distribution of patients according to Roussouly type was as following：Type Ⅰ,10 cases（19.61％）; Type Ⅱ,15 cases（29.42％）; Type Ⅲ,20 cases（39.22％）; Type Ⅳ,6 cases（l1.76％）.In Type Ⅰ：there were significant improvements（P＜0.01） in LL,UP arc,IVA4-5 and SS at postoperation and final follow-up compared with those at preoperation,but PT decreased.In Type Ⅱ and Ⅲ：IVA4-5 had significant improvement（P＜0.05） at the postoperation and final follow-up compared with that at preoperation,the LL at final follow-up significantly increased（P＜0.05） compared with that at preoperation,while the SS,PT and PI showed no significant differences.In Type Ⅱ,UP arc significantly increased at the final follow-up.In Type Ⅳ：the IVA4-5（P＜0.05） significantly increased with statistically significant differences to the preoperative,but there was no significant difference in LL,UP arc,SS,PT or PI between preoperation and postoperation.The ratio of C7PL/SFD significantly decreased at the postoperation and final follow-up compared with that at preoperation in all types.VAS,ODI,JOA scores at postoperation and final follow-up had significant improvement than the preoperatives.The general prevalence of rASD was 17.64％ in all patients.Analysis of rASD risk factors showed：age,follow-up time,PI,IVA4-5 were major risk factors.Conclusions：SL4/5 can significantly increase IVAL4-5,but has different effects to spine-pelvis sagittal alignment parameters according to the types of Roussouly.IVA4-5 is a significant risk factor of rASD,the older age,the longer follow-up time and higher PI values are more prone to rASD.