The hazard of the lumbar transpedicular screwing: radiological consideration for a correct path

To evaluate the anatomical relationship between lumbar vertebral bodies and major vascular structures through computed tomography (CT) imaging, with the aim of identifying high-risk trajectories for transpedicular screw placement and minimizing iatrogenic vascular injury. A retrospective analysis of 100 consecutive lumbar CT scans (T12–L5) was performed. The anterior surface of each vertebral body was divided into four sagittal quadrants (A–D). In each quadrant, the presence and distance of adjacent vascular structures (aorta, inferior vena cava, iliac arteries and veins) were recorded. Vessels located ≤ 5 mm from the vertebral body were considered at risk. Data were analyzed by vertebral level, quadrant, and type of vessel. Vascular structures were found within 5 mm of the vertebral body in 53.1% of cases. The incidence of vascular proximity increased from the upper to lower lumbar spine: 44.5% at T12, 40.2% at L1, 36.0% at L2, 51.0% at L3, 67.7% at L4, and 79.2% at L5. The most frequently involved vessels were veins, particularly the iliac veins at L4–L5 and the inferior vena cava from T12 to L3. Quadrants B and C had the highest frequency of vascular proximity, while quadrant D represented the most hazardous pathway, especially at lower levels. Transpedicular screw placement in the lumbar spine carries a measurable risk of vascular injury, which increases at lower vertebral levels and in certain quadrants. Detailed preoperative radiological assessment, including quadrant-based anatomical evaluation, is essential to identify safe screw trajectories and reduce the risk of iatrogenic vascular complications.