应用数字骨科技术获取腰椎双皮质椎弓根螺钉的置入参数

背景:对伴发骨质疏松患者,为提高脊柱固定稳定性进行椎体双皮质椎弓根螺钉固定是可行的方法。但双皮质椎弓根螺钉置入不当除了易误伤脊髓、神经根外,还会损伤椎前大血管和脏器,所以术前测量双皮质椎弓根螺钉置入参数很有必要。目的:应用CT和数字骨科技术,术前虚拟腰椎双皮质椎弓根螺钉置入,测量个体化双皮质腰椎椎弓根螺钉置入参数。方法:将骨质疏松患者L1-4CT扫描数据导入Mimics10.0软件和GE工作站,三维重建并虚拟椎弓根螺钉置入双皮质固定L1,3椎体,定位并测量置钉相关数据。结果与结论:通过Mimics10.0软件重建CT三维腰椎影像并虚拟椎弓根螺钉人字嵴顶点置入,测量椎弓根的最小宽径、虚拟置入双皮质椎弓根螺钉的矢状面角、内倾角(水平面角)、水平置入最大限深,推算出平行上终板置入的最大限深。获取个体化腰椎双皮质椎弓根螺钉置入数据,从而提高螺钉固定的安全度和精确性。

Parameters of bi-cortical pedicle screws implantation in the lumbar vertebrae with digital orthopedic technology

BACKGROUND： To improve the lumbar stability after operation, inserting bi-cortical pedicle screws in the vertebrae is viable when the patients associated with osteoporosis. But the bi-cortical pedicle screws improperly invert may lead to serious complications such as spinal cord, nerve root, abdominal aorta, inferior vena cava and organs damage. So it is important to measure the parameters of inverting the screws pre-operation. OBJECTIVE： To measure the preoperative individual parameters of inserting bi-cortical pedicle screws in the lumbar vertebrae with CT and digital orthopedic technique. METHODS： The image data of L 1-4 that scanned by CT was imported into the Mimics 10.0 software and GE workstation, and L 1-4 three-dimensional image was reconstructed. The individual parameters of inserting bi-cortical pedicle screws in the L1, 3 were measured. RESULTS AND CONCLUSION： The three-dimensional CT lumbar image was reconstructed clearly, and the placement of bi-cortical pedicle screws on the crista lambdoidalis was simulated by Mimics10.0 software. The minimum diameter, sagittal angle of simulated inserting bi-cortical pedicle screws, leaning angle （horizontal angle） and the horizontal depth were measured by the Mimics 10.0 software. Meanwhile, the limited depth of the screws when parallel to vertebral end-plate was calculated. It is a reliable method to get individual parameters of inserting bi-cortical pedicle screws in the lumbar vertebrae and it can improve the safety and accuracy of screw fixation.