重度僵硬性脊柱侧后凸手术后三维椎管内壁长度的变化

In-vivo change of the spine canal after surgical corrections of severe and rigid kyphoscoliosis

目的研究重度僵硬性脊柱侧后凸截骨手术后,椎管内壁长度的变化,以此测量脊髓在脊柱凸手术矫形过程中不同位置被拉伸或缩短的程度。方法回顾性分析2016年8月至2018年12月北京朝阳医院收治的10例重度脊柱侧后凸患者的临床及影像学资料,其中5例行Ponte截骨,5例行后路全椎体截骨(VCR截骨)。通过站立位X线测量术前及术后Cobb角;通过3D建模软件将CT图像重建成全脊柱3D模型,在椎弓根平面对椎管横截面进行测量和标记,最后连接所有平面椎管横截面生成完整3D模型。测量上下端椎(U/LEV)范围内,T2~L2范围内前侧、后侧、左侧、右侧和中央的椎管长度(SCL)。测量T2~L2间的垂直相对距离。手术前后数据比较采用t检验。结果5例行Ponte截骨患者,术后冠状位Cobb角改善89°±17°(56%±11%),矢状位改善84°±16°(56%±8%)。T2~L2凹侧SCL平均延长(9.9±4.8)mm,凸侧平均延长(6.0±12.7)mm;U/LEV间凹侧SCL平均延长(7.2±5.4)mm;凸侧U/LEV范围内SCL平均延长(-0.5±7.9)mm;T2~L2间椎体垂直距离平均改善(66.1±12.0)mm,U/LEV范围内平均改善(38.0±15.3)mm。5例行VCR截骨患者,术后冠状位Cobb角平均改善83°±19°(60%±10%),矢状位平均改善82°±22°(56%±10%),T2~L2凹侧SCL平均延长(-5.5±5.3)mm;凸侧平均延长(-14.0±6.6)mm;凹侧U/LEV范围内SCL平均延长(-8.3±8.4)mm;凸侧U/LEV范围内SCL平均延长(-20.7±11.6)mm;T2~L2间椎体垂直距离平均延长(41.5±12.4)mm。结论重度脊柱侧凸患者手术矫形后,凹侧椎管延长明显不同于凸侧,Ponte截骨导致凹侧椎管延长较凸侧多,VCR截骨导致凸侧缩短长度大于凹侧。

Objective To measure the length changes of the spine canal of patients with severe kyphosis after treatments of deformity using osteotomy surgeries.Methods Retrospectively investigated the data of 10 severe kyphosis patients who were treated between August of 2016 and December of 2018 at Beijing Chaoyang Hospital(5 with Ponte and 5 with posterior vertebra column resection(VCR)osteotomy surgeries).For each patient,the full-spine X-Ray images were used to measure Cobb angles before and after the surgery;3D CT images were used to construct a 3D model of the spine,including the T2 to L2 vertebrae and the spine canal.The 3D model was then used to measure the spinal canal lengths(SCLs)between the upper and lower vertebrae(U/LEV)and between T2-L2 vertebrae at 5 locations on the spine canal cross section(anterior,central,posterior,left and right locations),and the vertical distance between the T2 and L2 vertebrae before and after the surgery.The data were statistically analyzed using t tests.Results For the 5 patients of Ponte osteotomy,the Cobb angles were improved by 89°±17°(56%±11%)and 84°±16°(56%±8%)in the coronal and sagittal planes respectively after the surgery.The changes of the SCL between the T2-L2 vertebrae were(9.9±4.8)mm and(6.0±12.7)mm,and those were(7.2±5.4)mm and(-0.5±7.9)mm between the U/LEV,respectively at the concave and convex sides of the canal.The vertical distance between the T2-L2 vertebrae increased by(66.1±12.0)mm.For the 5 patients with VCR osteotomy,the Cobb angles improved by 83°±19°(60%±10%)and 82°±22°(56%±10%)in the coronal and sagittal planes,respectively.The changes of the SCL between the T2-L2 vertebrae were(-5.5±5.3)mm and(-14.0±6.6)mm,and those were(-8.3±8.4)mm and(-20.7±11.6)mm between the U/LEV,respectively at the concave and the convex sides of the canal.The vertical distance between the T2-L2 vertebrae increased by(41.5±12.4)mm.Conclusions The Ponte osteotomy significantly elongates the SCLs,especially at the concave side,and the VCR osteotomy shortens the spinal canal,resulting in significant compression of the spinal cord at the convex side.