Figure 8
Designation of screw insertion positions. (A) The central position is defined as the middle part of the superior and inferior endplates in the lateral plane of the vertebra, while the lower position is the lower third between the superior and inferior endplates. (B) The anterior position is defined as the middle of the anterior third of the vertebral body, the middle position is the middle of the middle third and posterior position is the middle of the posterior third.
