Abstract
BackgroundThrough the comparison of three-dimensional CT reconstruction between the supine position and the prone position, the relative position of thoracolumbar great vessels and vertebral body was studied, and the shortest safe distance between them was measured to improve the safety of bicortical pedicle screw insertion and reduce the risk of vascular injury.MethodsForty adults were selected to participate the research. Three-dimensional reconstruction of thoracolumbar (T9-L3) CT was performed in the prone position and the supine position. The relative distance between the Aorta/Inferior Vena Cava (IVC) and vertebral body was obtained as AVD/VVD respectively. The relative angle of the Aorta/ IVC and the vertebral body was calculated as ∠AOY/∠VOY. Self-controlled experiments were carried out in the prone and the supine positions, and the data obtained were analyzed using SPSS 22.0 statistical software.ResultsThe AVD of the prone position and the supine position was the shortest at T12 (3.18 ± 0.68 mm), but the difference was not statistically significant. The aorta of the T9-L3 segment was shifted from the anterolateral to the anteromedial. The ∠AOY of the other groups differed significantly between the prone and supine positions in all vertebrae except T12 and L1 (P < 0.05), and the aorta in the prone position was more anteromedial than that of supine position.With regard to VVD/∠VOY, there was no significant difference between the prone and supine positions (P ≥ 0.05), and the minimum VVD of L3 segment is greater than 5.4 mm. The IVC has no obvious mobility and is fixed in the range of 20 ° ~ 30 ° near the midline.ConclusionWhen using bicortical anchoring of pedicle screws, it is safe to ensure that the protruding tips of the screw is less than 3 mm. Due to the mobility of the aorta in different postures and individual differences in anatomy, the prone position CT can help doctors to make better preoperative plans and decisions.
Highlights
Through the comparison of three-dimensional CT reconstruction between the supine position and the prone position, the relative position of thoracolumbar great vessels and vertebral body was studied, and the shortest safe distance between them was measured to improve the safety of bicortical pedicle screw insertion and reduce the risk of vascular injury
The enhanced internal fixation will reduce the screw loosening, displacement and pullout, and improves the success rate of the operation [4,5,6,7,8,9]. This technique is at risk of damaging the blood vessels in the anterior part of the vertebral body [10,11,12]. To evaluate this risk and safely implement bicortical screw, the present study used imaging to examine the anatomical relationship between the great vessels and the vertebral body, and it explored ways to improve the accuracy of bicortical fixation and reduce the risk of vascular injury
The aorta of the T9-L3 segment tended to shift from the anterolateral side of the vertebral body to the anteromedial side of the vertebral body, as shown in Fig. 5, getting closer to the Y axis
Summary
Through the comparison of three-dimensional CT reconstruction between the supine position and the prone position, the relative position of thoracolumbar great vessels and vertebral body was studied, and the shortest safe distance between them was measured to improve the safety of bicortical pedicle screw insertion and reduce the risk of vascular injury. The enhanced internal fixation will reduce the screw loosening, displacement and pullout, and improves the success rate of the operation [4,5,6,7,8,9]. This technique is at risk of damaging the blood vessels in the anterior part of the vertebral body [10,11,12]. To evaluate this risk and safely implement bicortical screw, the present study used imaging to examine the anatomical relationship between the great vessels and the vertebral body, and it explored ways to improve the accuracy of bicortical fixation and reduce the risk of vascular injury
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
