以棘突顶点皮缘连线作为胸腰椎椎弓根经皮置钉矢状面进钉角度的参照

Angle of upper terminate plate parallel line of thoracolumbar vertebral body against the line between the percutaneous anatomic landmarks of the highest point of the spinous process

背景:胸腰椎椎弓根螺钉的置入在技术上要求很高并且涉及到辐射暴露,大量的射线对患者和外科医生都有严重的影响。目的:介绍一种以棘突顶点皮缘连线作为椎弓根螺钉矢状面进钉角度参照的经皮置钉技术,以有效减少术中辐射暴露。方法:收集100例正常成人的胸腰椎MRI(健康对照组),分为正常体质量组及肥胖组,分别测量T1-L5椎体上终板的平行线与相应棘突顶点皮缘连线的夹角并进行统计学分析。同时再收集100例L1椎体压缩性骨折患者MRI,分为正常体质量组及肥胖组,同样方法对L1椎体临近的上下椎体进行测量,即T12及L2棘突顶点皮缘连线与椎体上终板的交角,与健康对照组测得值分别比较,并进行统计学分析,得出棘突顶点皮缘连线与椎体上终板的角度。结果与结论:①健康对照组正常体质量者中,矢状面上棘突顶点皮缘连线与椎体上终板平行线夹角为87°-95°(T1-L4范围),健康对照组肥胖患者矢状位片上在86°-94°(T8-L2范围),2组平均值均为90°;②骨折组所测角度范围在90°附近,与健康对照组比较差异无显著性意义(P>0.05),提示该角度并不受椎体骨折影响;③结果表明在胸腰椎椎弓根螺钉徒手置钉手术中,正常体质量者T1-L4范围、肥胖者T8-L2范围矢状面上保持椎弓根螺钉置钉角度与棘突顶点皮缘连线夹角在90°左右,可使椎弓根螺钉与椎体上终板保持平行。提示以棘突顶点皮缘连线作为椎弓根螺钉矢状面进钉角度参照的经皮置钉技术是一项治疗脊柱骨折有效可行的方法。

BACKGROUND: Placement of thoracolumbar pedicle screws needs high technology and radiation exposure. Large amount of radiation makes serious effects on patients and the surgeons. OBJECTIVE: To introduce a percutaneous pedicle screw placement technique with reference to the percutaneous anatomic landmarks of the highest point of the spinous process, so as to effectively reduce intraoperative radiation exposure. METHODS: One hundred cases of normal thoracolumbar MRI were recruited and were divided into normal weight group and obese group. The angle of connection between the percutaneous anatomic landmarks of the highest point of the spinous process and the corresponding line between the parallel lines of the endplate was measured. At the same time, 100 cases of thoracolumbar MRI with thoracolumbar fracture were collected and divided into normal weight group and obese group. The same method was used to measure the angle between the two lines in adjacent vertebral segments (T12 and L1). The measured angle values of the fracture group and the normal group were compared and analyzed statistically to obtain the angle of the line between percutaneous anatomic landmarks of the highest point of the spinous process and the upper terminate plate. RESULTS AND CONCLUSION:(1) The angle of the parallel lines of the endplate against the line between percutaneous anatomic landmarks of the highest point of the spinous process was 87-95° at T1-L4 in the normal weight group, while the angle was 86-94° at T8-L2 in the obese group. The average angle was 90°.(2) The measured angle in thoracolumbar fracture group was around 90°. There was no significant difference between the normal group and the fracture group (P > 0.05).(3) In summary, if we keep the connection angle between the line between percutaneous anatomic landmarks of the highest point of the spinous process and the pedicle screws is about 90° in the thoracolumbar vertebral fracture fixation surgical procedure, we basically can ensure that the pedicle screw parallel to the upper terminate plate. The method of this percutaneous pedicle screw placement with reference to the percutaneous anatomic landmarks of the highest point of the spinous process is a safe, effective technique for treating the spinal fracture.