A lumbar epidural injection is usually recommended to treat pain originating from spinal nerve roots.1 This injection is typically considered:
- After initial nonsurgical treatments, such as medications and/or physical therapy, have been tried with insufficient or no pain relief,2 but before surgery is considered.
- If the patient is in too much pain to progress with physical therapy. An epidural injection may provide enough pain relief to engage in rehabilitative therapy.
Pain relief from these injections may help limit or eliminate the need for oral medications and postpone surgery for a few weeks or months in some cases.3,4 Sometimes, the need for surgery may also be potentially eliminated.
Epidural Steroid Injections Aim to Reduce Nerve Pain
Pain from irritated, inflamed, or compressed lumbar spinal nerve roots usually originate deep in the buttock and travels down the thigh and leg with possible lower back and/or foot pain. This condition is called lumbar radiculopathy and the symptoms are commonly referred to as sciatica.
Epidural steroid injections help control inflammation in lumbar radiculopathy, reducing or eliminating the sciatica symptoms. If the injection is successful in reducing pain, the results may last for a week or up to a year.1
Common Indications for Epidural Steroid Injections
A few common causes of lumbar radiculopathy when epidural steroid injections may be given are discussed below.
Lumbar Herniated discs
When a disc herniates, the inner jelly (nucleus pulposus) pushes through the outer fibrous covering (annulus fibrosis), inflaming and/or compressing the adjacent spinal nerve root. This mechanical pressure results in pain, weakness, and/or numbness along the distribution of the nerve.1
Lumbar Degenerative disc disease
The gradual breakdown of intervertebral discs may cause the collapse of disc space, bringing the adjacent vertebrae closer and resulting in a compression of the corresponding spinal nerve root.1
Foraminal spinal stenosis
The compression of nerve roots due to narrowing of the bony openings (foramina) for spinal nerves may cause radiculopathy pain. Stenosis may be secondary to herniated discs, degenerative changes in the bone, or arthritis of the vertebral facet joints.1
Epidural steroid injections may also be given to treat nerve pain due to spinal cysts or spondylolisthesis (slipping of one vertebra over the other).1
Less Common Indications for Epidural Steroid Injections
Back pain without radiculopathy may sometimes be treated with epidural steroid injections. A few examples include:
- Axial low back pain. This pain is confined to the lower back and may be caused due to inflammatory changes in the vertebral end plates (bony coverings of the inner surfaces of vertebrae), spinal dura (covering of the spinal cord), or spinal ligaments.5,6 Axial low back pain can also originate from degenerated discs.7 In general, injections for axial low back pain is usually considered when associated leg pain is also present.
- Neurogenic claudication. Back pain and leg pain (usually present in both legs) that occurs while walking variable distances and/or bending the spine backward. This pain is usually caused when the central spinal canal is stenosed, compressing the spinal cord.6
When Epidural Steroid Injections May Not be Given
The presence of certain health conditions may increase the possibility of risks and/or complications following epidural steroid injections. A few examples are discussed below.
Epidural steroids must not be given when the following conditions are present1:
- Infection in any part of the body, including the site of injection
- Bleeding disorders
- Tumors or cancer
Additionally, the injection must not be used if there is a known allergy to the steroid medication, local anesthetic, or the contrast dye used for fluoroscopy (live x-ray).
Epidural steroids may or may not be given when the following conditions are present1:
- Uncontrolled diabetes mellitus
- Heart problems, such as congestive heart failure
- Pregnancy, especially if fluoroscopy is used
A doctor may decide if the injection may be given in these cases depending on various factors, such as the patient’s age and overall health.
While epidural steroid injections may help control spinal pain for up to 1 year1, some patients may not experience any benefits from this procedure.