Manual and computer-assisted pedicle screw placement plans: A quantitative comparison

Abstract

In this paper, we present a quantitative comparison of manual and computer-assisted preoperative pedicle screw placement plans, obtained from three-dimensional (3D) computed tomography (CT) images of 17 patients with thoracic spinal deformities. Manual planning was performed by two spine surgeons by means of a dedicated software for planning of surgical procedures, while computer-assisted planning was based on automated 3D segmentation and modeling of vertebral structures from CT images, and automated modeling of the pedicle screw in 3D with maximization of the screw fastening strength. The analysis of the size (diameter and length) and insertion trajectory (pedicle crossing point, sagittal and axial inclinations) for 316 pedicle screws revealed a statistically significant difference in the screw size and insertion trajectory. However, computer-assisted planning did not propose narrower and shorter screws, which was reflected through a higher normalized screw fastening strength.