Did You Know?

Since the 1950s, Epidural Steroid Injections (ESIs) have played a major role in the non-surgical management of spine-related pain. Originally introduced to treat disc herniations and spinal stenosis, ESIs gradually expanded into other areas of the spine as medical understanding and techniques evolved.

In later years, steroids began to be injected not only around nerve roots but also into:

• Facet joints
• Sacroiliac joints (SIJ)
• Intervertebral discs (intra-discal)
• Ligaments supporting the spine

Types and Evolution of ESI Techniques

Early ESI methods were performed without imaging guidance—a practice known as “blinded” injection. These included:

• Blinded Interlaminar ESI (via the midline approach, commonly used in labor and delivery):
  
  • Miss rates up to 40%
  • No longer recommended
• Blinded Caudal ESI (injection into the base of the spine):
  
  • Miss rates up to 36%
  • No longer recommended

Imaging-Guided ESI: A Game-Changer

In the late 1980s, the introduction of fluoroscopic guidance—real-time X-ray imaging—dramatically improved the accuracy of epidural injections. This ushered in a new era of targeted spine care.

Three primary fluoroscopic approaches emerged:

• Transforaminal ESI (TFESI)
  
  • Targets individual nerve roots
  • Performed unilaterally or bilaterally
  • Most effective, with up to 80% of patients reporting improvement
• Caudal ESI
  
  • Second most effective approach
  • Especially beneficial at the L4-5 or L5-S1 levels
  • Often used if a TFESI is unsuccessful
• Interlaminar ESI
  
  • Entered in the midline but now guided by fluoroscopy
  • Least effective among the three
  • Less commonly performed then the above approaches

The development of image-guided ESIs marked a major advancement in spine care. Yet despite these improvements, limitations in long-term relief remain—leading clinicians to explore more sustainable, regenerative options such as Platelet-Rich Plasma (PRP).

Read more from the series “Evidence for Platelet-Rich Plasma in Spine Care”:

• The History of Epidural Steroid Injections
• How Many Steroid Injections Are Too Many? (Coming Soon)
• When Is a Steroid Injection Actually Warranted? (Coming Soon)
• How PRP Compares to Steroids in Spine Treatment (Coming Soon)
• The Protocol for Using PRP in Spine Care (Coming Soon)