短节段腰椎融合术后从站位到坐位的脊柱矢状位序列变化

目的:研究短节段腰椎融合术后患者从站位到坐位时的脊柱矢状位序列的变化,以及与正常人群在体位改变时的变化差异,探讨短节段腰椎融合术对不同体位下矢状位序列的影响。方法:回顾性分析2010年~2012年在北京大学第三医院行腰椎融合内固定术的患者资料58例(A组),其中男30例,女28例,年龄63.7±8.5岁(43~81岁),根据术中腰骶是否融合将A组分为腰骶融合组(A1组,26例)与腰骶未融合组(A2组,32例)。对照组为90例中老年健康志愿者(B组),其中男39例,女51例,平均年龄53.2±5.7岁(42~71岁)。所有受试者均行站立位和坐位时的全脊柱X线片检查,应用院内图片存档和通信系统(PACS)测量脊柱矢状位轴(SVA)、T1骨盆角(TPA)、骨盆入射角(PI)、骨盆倾斜角(PT)、骶骨倾斜角(SS)、腰椎前凸角(LL)、胸椎后凸角(TK)。采用独立样本t检验分别比较A组与B组的差异,以及A1组、A2组和B组在站位和坐位时矢状位序列变化的差异。结果:A组患者从站位到坐位时,SVA增加(19.7±33.1mm vs 37.9±27.4mm,P<0.001),TPA增加(11.7°±6.2°vs 17.1°±8.0°,P<0.001),LL减小(41.6°±13.6°vs 35.6°±14.3°,P<0.001),TK减小(30.5°±12.0°vs 28.0°±12.1°,P<0.05),PT增加(15.1°±6.7°vs 19.4°±9.5°,P<0.001),SS减少(32.3°±8.7°vs 28.7°±9.9°,P<0.001)。A组患者LL和TK的减小,以及SVA的增加显著小于B组(P<0.05),其中A1组PT的增加显著小于B组(2.1°±7.1°vs 6.1°±8.9°,P<0.05),而A2组PT的增加程度与B组无统计学差异(6.0°±6.6°vs 6.1°±8.9°,P>0.05)。结论:短节段腰椎融合术后的脊柱从站位到坐位时表现为骨盆后旋,胸、腰椎曲度变直,脊柱矢状轴前移,但其胸腰椎曲度变化和矢状轴前移的幅度显著小于对照组。短节段腰椎融合术会限制坐位时骨盆的后旋。

The differences in the sagittal alignment of patients who had short-segment lumbar fusion when moving from standing to sitting

Objectives:To explore how the sagittal alignment of spine after short-segment lumbar fusion changes from standing to sitting and compare this change with that of healthy people.Methods:The lateral whole spinal radiography in the standing and sitting positions of 58 patients(group A,30 males,28 females;mean age,63.7±8.5 years)who underwent lumbar fusion surgery in Peking University Third Hospital was reviewed.And the group A was divided into the group with lumbosacral fusion(group A1,26 subjects)and the group without lumbosacral fusion(group A2,32 subjects).The control group contained 90 healthy elderly volunteers(group B,39 males,51 females;mean age,53.2±5.7 years).The parameters including sagittal vertical axis(SVA),T1-pelvic angle(TPA),pelvic incidence(PI),sacral slope(SS),pelvic tilt(PT),lumbar lordosis(LL)and thoracic kyphosis(TK)were measured.The parameters in different position(group A)were compared by using paired t test and the differences in changes from standing to sitting between patients(group A,A1,A2)and the control group(group B)were compared by using independent t test.Results:When moving from standing to sitting in group A,SVA increased(19.7±33.1mm vs 37.9±27.4mm,P<0.001),followed by decrease in LL(41.6°±13.6°vs 35.6°±14.3°,P<0.001)and TK(30.5°±12.0°vs 28.0°±12.1°,P=0.006),and TPA increased(11.7°±6.2°vs 17.1°±8.0°,P<0.001)with the increased in PT(15.1°±6.7°vs 19.4°±9.5°,P<0.001)and SS(32.3°±8.7°vs 28.7°±9.9°,P<0.001).Compared with the control group,the patients in group A showed smaller increase in TPA,SVA,PT and smaller decrease in LL,TK(P<0.05),while the patients with lumbosacral fusion(group A1)presented significantly smaller increase in PT(2.1°±7.1°vs 6.1°±8.9°,P<0.05).But the patients without lumbosacral fusion(group A2)showed similar PT(6.0°±6.6°vs 6.1°±8.9°,P>0.05)compared to the control group.Conclusions:When moving from standing to sitting,the spine went forwards with a straighter curvature in lumbar and thoracic spine,followed by pelvic retroversion.However,the straightening in lumbar and thoracic curve,as well as increase in SVA was smaller in patients,and the lumbosacral fusion would limit the pelvic retroversion in the sitting position.