Biomechanical effects of posterior lumbar interbody fusion with vertical placement of pedicle screws compared to traditional placement

Figure 1 Finite element models of vertebral bodies and pedicle screws.

Figure 2 Diagram depicting application of loads during human forward bending, backward extension, rotation, and lateral bending. A: Extension; B: Forward bending; C: Right lateral bending; D: Left lateral bending; E: Right rotation; F: Left rotation.

Figure 3 Vertebral stress distribution map. A: Vertebral stress distribution at 0-degree transverse section angle (TSA); B: Vertebral stress distribution at 17-degree TSA.

Figure 4 Rod system stress distribution. A: Stress distribution of the pedicle screw system at 0-degree transverse section angle (TSA); B: Stress distribution at 17-degree TSA.