S1 Transforaminal Epidural Steroid Injection

Abstract

The transforaminal epidural steroid injection was developed to deliver injectate to the ventral epidural space because the putative site of pain generation is the posterior anulus and the ventral aspect of the nerve root sleeve. The transforaminal epidural steroid injection technique described in this chapter is performed for potentially therapeutic value only.

Keywords

disc herniation, epidural steroid injection, lumbar, radiculopathy, sacral, transforaminal

Note: Please see pages ii , iii for a list of anatomic terms/abbreviations used throughout this book.

The transforaminal epidural steroid injection delivers injectate to the ventral epidural space, the posterior anulus, and the ventral aspect of the nerve root sleeve.

Trajectory View

Confirm the level (with the anteroposterior view) before obtaining the trajectory view (see Chapter 1 ).

Tilt the fluoroscope cephalad ( Fig. 11.1 ).

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Line up the superior S1 end plate by tilting the beam cephalad. The goal is to optimize visualization of the dorsal S1 foramen. Squaring off the superior S1 end plate provides an initial starting point for optimizing visualization.

Oblique the fluoroscope ipsilaterally .

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The target needle destination is the dorsal S1 foramen, just inferior to the S1 pedicle.
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The dorsal S1 foramen is better visualized with a slight ipsilateral oblique view. Optimal visualization is dependent on anatomy, and, in some individuals, it may be achieved without using the oblique view. Repositioning the fluoroscope to a less cephalad tilt may help in visualizing the dorsal S1 foramen.
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Aim to be in the superolateral aspect of the posterior S1 foramen because the nerve runs inferolateral.
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The ventral S1 foramen may be in line with the dorsal S2 foramen as a result of the cephalad tilt of the fluoroscope beam.