Placement of pedicle screws using three-dimensional fluoroscopy-based navigation in lumbar vertebrae with axial rotation

Abstract

Despite potential advantages of three-dimensional fluoroscopy-based navigation, there still remain a lot of controversies about the indications of this technology, especially whether it is worthy of being used in placement of pedicle screws in lumbar spine. However, according to the inconsistent conclusions reported in the literature and our experiences, the traditional method relying on anatomical landmarks and fluoroscopic views to guide lumbar pedicle screw insertion is unable to meet the requirement of precise screw placement. Based on our observation, screw malposition seems to occur concomitant with vertebral axial rotation which is a ubiquitous phenomenon. Threedimensional fluoroscopy-based navigation can provide the most valuable axial images in real-time, so it may be useful for placement of pedicle screws in lumbar spine. This study was intended to evaluate the effect of axial rotation of lumbar vertebrae on the accuracy of pedicle screw placement using the traditional method, as well as assess the value of three-dimensional fluoroscopy-based navigation in improving the accuracy. Sixteen lumbar simulation models at different degrees of axial rotation (0°, 5°, 10°, and 20°), with every four assigned the same degree, were equally divided into two groups (traditional method group and three-dimensional fluoroscopy-based navigation group). Random placement of pedicle screws was carried out, followed by CT scan postoperatively. Then the outer pedicle cortex contours were depicted from reconstructed sectional pedicle images using Photoshop. The accuracy of pedicle screw placement was evaluated by determining the interrelationship between screw trajectory and pedicle cortex (quality), and measuring the shortest distance from pedicle screw axis to outer cortex of the pedicle (quantity). Eighty pedicle screws were implanted, respectively, in each group. In traditional method group, statistical difference existed in the accuracy of pedicle screw placement at different axial rotational degrees (P \ 0.05). With degrees increasing, the accuracy declined. The accuracy of threedimensional fluoroscopy-based navigation group was higher than traditional method group in vertebrae with axial rotation (P \ 0.01). In qualitative evaluation, the accuracy of the two methods had statistical difference when the degree was 20°, and in quantitative evaluation, statistical difference existed in 5°, 10°, and 20°of vertebral axial rotation.

Accuracy of lower cervical pedicle screw placement with assistance of distinct navigation systems: a human cadaveric study

“…Although the 3D images, especially the reconstructed images, were not as exact as CT images, the sections of the 3D images were of no difference from the CT images and could satisfy the need in accuracy. Our previous studies demonstrated that the safety and accuracy of the upper cervical screw placement and lumbar vertebrae with axial rotation were also substantially improved [13,14]. Additionally, we performed an analysis of 818 cases of navi- The usage of virtual fluoroscopy navigation and CT-based navigation has dramatically declined in our department since then.…”

Intraoperative image-guided spinal navigation: technical pitfalls and their avoidance

“…12,27,43,64,66 Scheufler et al reported the accuracy of cervical (99.3%), thoracic (97.8%), and lumbar (94.4%) pedicle-screw placement using CT-based neuronavigation systems. 58,59 Silberman et al compared freehand with navigation-guided pedicle screw insertion and found a breach rate of 5.9% with the freehand technique and a breach rate of 1% using navigation for lumbar screw placement.…”

Cost-effectiveness of confirmatory techniques for the placement of lumbar pedicle screws

“…Several studies have demonstrated a role for 3D fluoroscopy in improving accuracy of pedicle screw placement. 26,28,29 Although there are data to support either the use of multimodality neurophysiological monitoring or the use of isocentric fluoroscopy to confirm pedicle screw placement, there are no studies that directly compare these 2 techniques or determine cost-effectiveness of each modality.…”