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Fluoro-anatomy of the Lumbar Spine - Dr Debjyoti Dutta. MD. FIPP. POUS (MSK)

Fluoro Anatomy Of the Lumbar Spine

Introduction: Fluoro-anatomy of the Lumbar Spine

Understanding the Fluoro-anatomy of the Lumbar Spine is paramount for any medical professional involved in pain management interventions or spinal procedures. Fluoroscopy serves as a crucial tool for visualizing the intricate structures of the spine in real-time, aiding in accurate diagnosis and precise treatment delivery. In this comprehensive guide, we will delve into the fluoroscopic anatomy of the lumbar spine, discussing its basic components, imaging techniques, and variations encountered in clinical practice.

Basic Anatomy of the Lumbar Spine

The lumbar spine consists of five vertebrae labelled L1 to L5, forming the lower region of the vertebral column. Each vertebra comprises various anatomical structures essential for understanding fluoroscopic images and conducting procedures effectively.

Lumbar Spine Lateral Image

Vertebral Components of the Lumbar Spine

1. Transverse Process (TP): These bony projections extend laterally from the vertebrae, serving as attachment sites for muscles and ligaments.

2. Spinous Process (SP): SPs are posterior projections arising from the vertebral arch, providing attachment points for muscles and contributing to spinal stability.

3. Superior Articular Process (SAP): SAPs articulate with the corresponding inferior articular processes of the superior vertebra, forming facet joints that facilitate spinal movement.

4. Inferior Articular Process (IAP): IAPs articulate with the superior articular processes of the inferior vertebra, forming facet joints crucial for spinal stability and motion.

5. Neuroforamen/Intervertebral Foramen (NF): These are passageways through which spinal nerves exit the spinal canal, branching out to various parts of the body.

Neuroforamen/Intervertebral Foramen (NF): These are passageways through which spinal nerves exit the spinal canal, branching out to various parts of the body.

Anatomy of the Typical Lumbar Vertebra
Anatomy of the Typical Lumbar Vertebra

Lateral Image of the Lumbar Spine

Curves of the Lumbar Spine

Imaging Techniques for the Lumbar Spine

Fluoroscopic imaging allows for dynamic visualization of the lumbar spine, enabling healthcare providers to perform precise interventions. Three primary fluoroscopic views are commonly utilized: Anterior-Posterior (AP), Lateral, and Oblique.

AP (Anterior-Posterior) View:

In the AP view, the patient lies supine, and the X-ray beam passes through the anterior aspect of the body, projecting images onto the fluoroscopy monitor. Key principles for obtaining optimal AP images include:

  • Aligning the spinous processes midline: This ensures proper orientation and symmetry of the vertebrae.

  • Flattening the endplates at the targeted level: By adjusting the C-arm position, the endplates should appear flat, facilitating accurate needle placement.

  • Accounting for spinal curvature variations: Individual spinal curvatures may necessitate adjustments in C-arm positioning to achieve ideal imaging alignment.

AP View Lumbar Spine

Lateral View:

The lateral view provides a side-on perspective of the lumbar spine, allowing visualization of vertebral alignment and intervertebral spaces. Important considerations for obtaining clear lateral images include:

  • Ensuring flat endplates: Vertebral bodies should appear rectangular, indicating proper alignment and minimizing distortion.

Outlining neuroforamen: Clear delineation of neuroforamen aids in identifying nerve root pathology and guiding needle insertion during procedures.

Lateral View Lumbar Spine on C Arm

Oblique View (Scotty Dog View):

The oblique view, also known as the Scotty Dog view, offers a tilted perspective of the lumbar spine, particularly useful for visualizing facet joints. Key aspects of the oblique view include:

  • Aligning the facet joints parallel to the X-ray beam: This creates a "down-the-barrel" view, where facet joints appear translucent, facilitating accurate needle placement.

  • Identifying anatomical landmarks: The Scotty Dog analogy helps localize key structures, such as transverse processes (nose) and superior articular processes (ear).

Oblique View Lumbar Spine

Variations and Clinical Considerations: Fluoro-anatomy of the Lumbar Spine

While the lumbar spine typically consists of five vertebrae (L1-L5), variations in anatomy may occur, presenting challenges during procedures. Some common variations include:

  • Additional lumbar vertebrae (e.g., L6): Rarely, individuals may exhibit extra lumbar vertebrae, necessitating careful counting and localization during interventions.

  • Sacralization and lumbarization: Anomalies such as sacralization of the lowest lumbar vertebra or lumbarization of the upper sacrum can affect spinal morphology and require adaptation of procedural techniques.

Scotty Dog View


Fluoroanatomy of the lumbar spine is essential knowledge for medical students embarking on careers in pain management or interventional procedures. Mastery of basic vertebral anatomy, fluoroscopic imaging techniques, and recognition of anatomical variations are fundamental for safe and effective patient care. By understanding the principles outlined in this guide, medical students can develop the skills necessary to navigate the complexities of lumbar spine interventions with confidence and proficiency.

About The Author

Dr Debjyoti Dutta

Dr. Debjyoti Dutta is a highly regarded pain specialist and acclaimed author, affiliated with Samobathi Pain Clinic and Fortis Hospital in Kolkata. Presently, he serves as a registrar at the Indian Academy of Pain Medicine, specializing in musculoskeletal ultrasound and interventional pain management. Dr. Dutta's influential publications, including "Musculoskeletal Ultrasound in Pain Medicine" and "Clinical Methods in Pain Medicine," underscore his commitment to advancing effective pain management strategies. Moreover, he plays a crucial role as a faculty member for the Asian Pain Academy Courses, facilitating exceptional pain management fellowship training in Kolkata, India. Through his dedicated efforts, Dr. Dutta significantly contributes to the professional development and education of individuals in the field.




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