A novel approach to navigated implantation of S-2 alar iliac screws using inertial measurement units

作者：Jost Gregory F^*; Walti Jonas; Mariani Luigi; Cattin Philippe

来源：Journal of Neurosurgery-Spine, 2016, 24(3): 447-453.

DOI：10.3171/2015.6.SPINE1594

• spine
• navigation
• S-2 alar iliac screws
• image-guided surgery
• inertial measurement unit
• sacral

OBJECT The authors report on a novel method of intraoperative navigation with inertial measurement units (IMUs) for implantation of S-2 alar iliac (S2Al) screws in sacropelvic fixation of the human spine and its application in cadaveric specimens.
METHODS 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 S2Al screws. The technique was performed without any intraoperative imaging. Screw positions were analyzed on postoperative CT scans.
RESULTS Seventeen of 18 screws showed a good S2Al screw trajectory. Compared with the postoperatively measured tilt angles of the S2Al screws, the IMU readings on the screwdriver were within an axial plane deviation of 0 degrees to 5 degrees in 15 (83%) and 6 degrees to 10 degrees in 2 (11%) of the screws and within a sagittal plane deviation of 0 degrees to 5 degrees in 15 (83%) and 6 degrees to 10 degrees in 3 (17%) of the screws.
CONCLUSIONS IMU based intraoperative navigation may facilitate accurate placement of S2Al screws.

• 出版日期2016-3