Jost Gregory F, Walti Jonas, Mariani Luigi, Cattin Philippe
Spine Surgery and.
Medical Image Analysis Center, University of Basel, Switzerland.
J Neurosurg Spine. 2016 Mar;24(3):447-53. doi: 10.3171/2015.6.SPINE1594. Epub 2015 Nov 13.
The authors report on a novel method of intraoperative navigation with inertial measurement units (IMUs) for implantation of S-2 alar iliac (S2AI) screws in sacropelvic fixation of the human spine and its application in cadaveric specimens.
Screw trajectories were planned on a multiplanar reconstruction of the preoperative CT scan. The pedicle finder and screwdriver were equipped with IMUs to guide the axial and sagittal tilt angles of the planned trajectory, and navigation software was developed. The entry points were chosen according to anatomical landmarks on the exposed spine. After referencing, the sagittal and axial orientation of the pedicle finder and screwdriver were wirelessly monitored on a computer screen and aligned with the preoperatively planned tilt angles to implant the S2AI screws. The technique was performed without any intraoperative imaging. Screw positions were analyzed on postoperative CT scans.
Seventeen of 18 screws showed a good S2AI screw trajectory. Compared with the postoperatively measured tilt angles of the S2AI screws, the IMU readings on the screwdriver were within an axial plane deviation of 0° to 5° in 15 (83%) and 6° to 10° in 2 (11%) of the screws and within a sagittal plane deviation of 0° to 5° in 15 (83%) and 6° to 10° in 3 (17%) of the screws.
IMU-based intraoperative navigation may facilitate accurate placement of S2AI screws.
作者报告一种使用惯性测量单元（IMU）进行术中导航的新方法，用于在人体脊柱骶骨盆固定中植入S-2翼髂（S2AI）螺钉及其在尸体标本中的应用。
在术前CT扫描的多平面重建上规划螺钉轨迹。椎弓根探测器和螺丝刀配备IMU以引导计划轨迹的轴向和矢状倾斜角度，并开发了导航软件。根据暴露脊柱上的解剖标志选择入点。参考后，在计算机屏幕上无线监测椎弓根探测器和螺丝刀的矢状和轴向方向，并与术前计划的倾斜角度对齐以植入S2AI螺钉。该技术在没有任何术中成像的情况下进行。术后CT扫描分析螺钉位置。
18枚螺钉中有17枚显示出良好的S2AI螺钉轨迹。与术后测量的S2AI螺钉倾斜角度相比，螺丝刀上的IMU读数在轴向平面偏差方面，15枚（83%）螺钉在0°至5°范围内，2枚（11%）螺钉在6°至10°范围内；在矢状平面偏差方面，15枚（83%）螺钉在0°至5°范围内，3枚（17%）螺钉在6°至10°范围内。
基于IMU的术中导航可能有助于S2AI螺钉的准确置入。
