基于数字技术的国人下腰椎椎弓根螺钉置钉角度特征

背景：椎弓根螺钉内固定是目前脊柱手术的主流术式，置钉安全性的关键是使螺钉通过椎弓根中心，置钉角度是决定修复质量的关键因素，以往文献中确定置钉角度多以患者躯体作为参照物，容易被体位等因素干扰。 目的：应用数字技术以椎体局部解剖标志为参照物对下腰椎椎弓根螺钉置钉角度进行测量。 方法：选取100例患者的3D-CT资料，将第4，5腰椎进行三维重建后利用数字技术进行模拟手术，实现最佳位置置钉。完成模拟置钉操作以后，对椎弓根螺钉的角度进行测量，以螺钉中线与棘突中线所在平面的夹角作为冠状位角度，以螺钉中线与椎体上表面所在平面的夹角作为矢状位角度。 结果与结论：测量结果表明，各角度均较以往文献中所介绍的角度大，考虑为选取参照标志不同所致。各角度值的标准差也较大，说明椎弓根解剖差异较大，因此应注重个体化置钉。这种以单个椎体的解剖标志作为定位参考的方法可以最大程度避免体位的干扰，与术前三维重建等数字技术相结合，更符合个体化置钉的要求，能有效提高置钉的准确性。中国组织工程研究杂志出版内容重点：人工关节；骨植入物；脊柱；骨折；内固定；数字化骨科；组织工程

Characteristics of lower lumbar pedicle screw angle in Chinese population using digital technology

BACKGROUND:Pedicle screw fixation is the mainstream type of spine operation currently. The key point of the fixation is to make the screw pass through the center of pedicle. The angle of pedicle screw implantation is a key factor for repair quality. In previous literatures, angle of pedicle screw is determined according to the patient body, and is easily disturbed by factors such as position of the body.  OBJECTIVE:To determine the inserting angle of pedicle screw of lower lumbar spine taking local anatomic landmark as a reference using digital technology. METHODS:3D-CT data of 100 patients were selected. The fourth and fifth lumbar vertebrae received three-dimensional reconstruction, and the operation was simulated using digital technology to achieve optimal placement. After simulation, the angle of pedicle screw was measured. The angle of the planes of the midline of the screw and the midline of the spine served as coronal angle. The angle of the planes of the midline of the screw and the upper surface of the vertebral body served as sagittal angle.  RESULTS AND CONCLUSION:Measure results suggest that each angle was bigger than the angle in previous studies, which might be induced by different reference markers. Standard deviation of each angle was also big. These findings verify that the anatomical differences of pedicles were apparent. Thus, we should insert the  pedicle screws individually. Method of locating reference using anatomic landmarks of a single vertebral body can maximize to avoid interference posture. The combination with preoperative three-dimensional reconstruction is more in line with the requirements of pedicle screw, and can effectively improve the accuracy of pedicle screws.