青少年特发性脊柱侧凸患者顶椎区脊髓位置变化及其临床意义

Variation and its clinical relevance of the spinal cord at the apex of the curve in adolescent idiopathic scoliosis

目的:分析青少年特发性脊柱侧凸(AIS)患者顶椎区脊髓偏移和旋转情况,并探讨其临床意义。方法:在28例AIS患者横断面MRI图像上测量顶椎区脊髓中心到椎管前、后内壁及凹、凸侧内壁的距离和脊髓、椎体的旋转角度,将脊髓旋转与椎体旋转的关系按Maruta分型分为O型、U型和R型,并分析脊髓在椎管内的位置及脊髓位置与Cobb角、脊髓旋转角度、椎体旋转角度之间的相关性。结果:顶椎区脊髓中心距脊柱凹侧、凸侧椎管内壁距离分别为7.13±1.89mm、13.68±2.93mm,距凹侧距离明显小于距凸侧距离(t=-9.56,P<0.01);距椎管内壁前、后缘距离分别为7.50±1.63mm、6.99±1.61mm,两者比较无显著性差异(t=1.22,P=0.23)。椎体旋转角度为17.53°±6.70°,脊髓旋转角度为16.46°±9.16°,O型8例,U型13例,R型7例。脊髓旋转角度与椎体旋转角度、Cobb角及脊髓中心到凸凹侧椎管内壁的差值之间均呈正相关(分别为r=0.45,P=0.01;r=0.43,P=0.02;r=0.64,P<0.01),与脊髓中心到椎管内壁前后缘的差值之间无显著相关性(r=0.28,P=0.15)。结论:AIS患者顶椎区脊髓向凹侧偏移,椎体与脊髓都存在旋转,脊髓的旋转方向因人而异。在行后路脊柱矫形椎弓根螺钉置入时,应特别注意凹侧脊髓及神经根,避免损伤。

Objective：To analyze the shift and rotation of spinal cord at the apex of the curve in adolescent idiopathic scoliosis （AIS） by MRI and explore its clinical relevance.Method：The MRI images from twentyeight cases of AIS were collected and analyzed.The distance between the center of spinal cord and the four inner wall of vertebral canal,and the rotational angle of the spinal cord and vertebral body at the apex of the curve in AIS were recorded respectively.According to the relationship between the rotational angle of the spinal cord and vertebral body,the patients were classified into three distinct groups termed as type O,type U and type R.The relationship between rotation and shift of the spinal cord at apical region,as well as the rotation of vertebra,Cobb angle were analyzed either.Result：The average distance from the center of spinal cord to the inner wall of vertebral canal on the convex side was 13.68±2.93mm,and 7.13±1.89mm on the concave side,with the latter less than the former（ t=-9.56,P〈0.01）.The average distance from the center of spinal cord to the anterior inner wall and posterior inner wall of vertebral canal was 7.50±1.63mm and 6.99±1.61mm respectively with no significant difference （t=1.22,P=0.23） noted.The average rotational angle of vertebral was 17.53°±6.70° with the spinal cord average tilt angle of 16.46°±9.16°.There were 8 cases of type O,13 cases of type U ,7 cases of type R.The spinal cord tilt was statistically correlated with the rotation angle of vertebral, Cobb angle and the distance variation from the center of spinal cord to the inner wall of vertebral canal on convex and concave side respectively（r=0.45,P=0.01, r=0.43,P=0.02, r=0.64,P〈0.01）,while the spinal cord shift was not statistically correlated with the distance variation from the center of spinal cord to the anterior and posterior inner wall of vertebral canal （r=0.28.P=0.15）.Conclusion：The shift of spinal cord to concavity occurred at the apex of the eurve in AIS and the rotation of spinal cord occurred individually.It should be cautious to avoid injury to the spinal cord and nerve roots while implanting pediele screw during posterior approach.