Caudal and Lumbar Epidural Steroid Injection

For Low Back and Leg Pain

An epidural steroid injection is an outpatient procedure for treating low back and leg pain.

What is epidural space?

The dura is a protective covering of the spinal cord and its nerves.  The space surrounding the dura is called the epidural space.  In the lower back it is called the lumbar epidural space.

What causes pain in the epidural space?

The lumbar area of the spine has five bones, called vertebrae.  Soft discs found between these vertebrae cushion them, hold them together, and control motion.  If a disc tears, chemicals inside may leak out. This can inflame nerve roots or the dura, and cause pain.  A large disc tear may cause a disc to bulge, inflaming nerve roots or the dura, and cause pain.  Bone spurs, called osteophytes, can also press against nerve roots and cause pain.

How do I know if I have disc and nerve root pain?

If you have pain in your low back when you bend your back, you may have lumbar disc and dural inflammation.  If pain travels to your leg when you move your back, you may have nerve root inflammation.  Common tests such as MRIs can show disc bulges and nerve root compression, but may not show a torn and leaking disc.  A lumbar epidural injection may provide relief if disc problems, or dural, or nerve root inflammation are causing your pain.

What is an epidural steroid injection?

In a lumbar epidural injection, a corticosteroid (anti-inflammatory medicine) is injected into the epidural space to reduce inflammation.  A local anesthetic (numbing medicine) may also be injected.  When it is done through the bony opening in your tailbone this is called a caudal epidural injection. 

What happens during an injection?

A local anesthetic will be used to numb your skin.  The doctor will then insert a thin needle directly into the epidural space. Fluoroscopy, a type of x-ray, must be used to ensure the safe and proper position of the needle.  A dye may also be injected to make sure the needle is at the correct spot.  Once the doctor is sure the needle is correctly placed, the medicine will be injected.