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Updated: Sep 26, 2025
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Three-dimensional Navigation-guided, Prone, Single-position, Lateral Lumbar Interbody Fusion Technique
Published on: July 15, 2021
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Anatomical positional changes in the lateral lumbar interbody fusion
Shashank V Gandhi1, Robert Dugan2, Samuel H Farber2
1Texas Back Institute, 6020 W. Parker Road, Suite 200, Plano, TX, 75093, USA. Shashankvg@gmail.com.
Summary
Patient positioning significantly alters lumbar anatomy, with the lateral-flexed position causing the greatest anterior psoas movement. Understanding these anatomical shifts is crucial for safe and efficient minimally invasive spine surgery approaches.
Area of Science:
- Spine surgery
- Anatomy
- Medical imaging
Background:
- Anterior lumbar interbody fusions (ALIFs) and lateral lumbar interbody fusions (LLIFs) are increasingly used for adult spinal conditions.
- Surgical techniques are evolving, with modifications like lateral-ALIF and prone-LLIF aimed at improving efficiency.
Purpose of the Study:
- To characterize anatomical changes in the surgical corridor with varying patient positions.
- To provide data for optimizing surgical approaches like ALIF and LLIF.
Main Methods:
- MRI scans of 10 healthy volunteers were analyzed in five positions: supine, prone (flexed/extended hips), and lateral (flexed/extended hips).
- Anatomical changes in the psoas muscles, inferior vena cava, aorta, and iliac vessels were assessed relative to spinal disc spaces (L1-S1).
Main Results:
- The psoas muscle showed the most anterior elongation in the lateral-flexed position compared to supine.
- The psoas muscle was 'thinnest' in the lateral-extended position.
- Vascular structures (IVC, aorta) shifted significantly, with the IVC moving medially and the aorta laterally in the lateral-flexed position compared to prone-extended.
Conclusions:
- Patient positioning causes significant movement of the psoas muscle (and lumbar plexus) and vasculature.
- Knowledge of these positional anatomical changes is vital for preoperative planning and safe intraoperative execution of spine surgeries.
- The lateral-flexed position demonstrates the greatest anterior displacement of the psoas and vessels, while the prone-extended position shows the least.
