Lumbar Spine Fluoroscopic Anatomy for the Pain Management Interventionalist

This article is designed to review all the basics around spine anatomy that would be helpful for performing procedures. Any pain management inverventionalist/proceduralist will rely on this basic anatomy, understanding of fluoroscopy images and C-arm use. It is written with a few basic goals:

  • Review basic vertebrae and spine anatomy
  • Discuss that in the context of fluoroscopic images and C-Arm positioning for procedures
  • Outline basic principles that can set a foundation for the various articles on this site

Basic Anatomy

There are generally 5 lumbar vertebrae. Most procedures revolve around knowing the basic structures of the vertebrae in the diagram and are referenced throughout this site:

  • Transverse process (TP)
  • Spinous process (SP)
  • Superior articulating process (SAP)
  • Inferior articulating process (IAP)
  • Neuroforamen (NF)

AP (Anterior-Posterior) fluoroscopy view

  • The spinous processes should be midline.
  • Flatten the endplates at the level that you’re working on.
  • With significant scoliosis you can’t get all SPs midline, so you do so at the levels you’re interested in.
lumbar medial branch block anterior posterior fluoroscopy
Note spinous process mostly aligned vertically and midline (blue). Target here is sacral ala with the needle so the top of sacrum is leveled off (red)

Lateral fluoroscopy view

L3 lumbar medial branch block technique fluoroscopic lateral view

Oblique/scotty dog fluoroscopy view

  • Attempt to look down the barrel of the facet joint at the level you’re working at. This means you see the facet joint straight on so it is lucent/transparent
  • Scotty dog (highlighted here in green)
  • Nose = TP, ear = SAP, front foot = IAP, body = lamina
scotty dog diagram fluoroscopy left L4
front half of the scotty dog outlined (green), the superior endplate of L4 is flat (red), the L3-L4 joint is “down the barrel” so it’s translucent (blue).

EXAMPLE 1: You want to place a needle at the junction of the TP and SAP at L4 on the left (also known as a left lumbar medial branch block at L4).

Naming/Numbering of bony structures and nerve roots

(coming soon)