Fig 1.
Schematic representation of a vertebral body instrumented with pedicle screws following the traditional trajectory (left) and the cortical bone trajectory (right). Note the smaller distance between the screw heads and the more sagittal orientation of the cortical bone trajectory configuration. Figure generated by the authors.
Table 1.
Specimen overview.
Fig 2.
The setup used for biomechanical testing can be used for flexion-extension and lateral shear (left), lateral bending and anteroposterior shear (center) and axial rotation and axial compression-decompression (right). Figure adapted from [18].
Fig 3.
CBT screw-rod construct without horizontal cross-connector (left) and augmented with one horizontal cross-connector (right). Figure generated by the authors.
Fig 4.
Boxplots for the range of motion (ROM) for uninstrumented, instrumented and cross-connector configuration between TT (green, left) and CBT (blue, right) shown for flexion-extension, lateral bending, axial rotation, anteroposterior shear, lateral shear and axial compression/decompression. Significant differences between the configurations are marked with asterisks (p<0.05), TT = traditional trajectory, CBT = cortical bone trajectory. Figure generated by the authors.
Fig 5.
Scatter plot for the range of motion (ROM) over the rod-rod distance for instrumented (triangles) and cross-connector-configuration (circles) shown for all six loading directions. No statistically significant correlations were observed. Linear regression fit and their parameters are reported to illustrate the data distribution. Figure generated by the authors.
Table 2.
Recorded range of motion.
Table 3.
Reduction in range of motion due to the addition of one horizontal cross-connector.