How It Works
An epidural steroid injection (ESI) is a combination of a corticosteroid with a local anesthetic pain relief medicine. Corticosteroids are strong anti-inflammatory medicines used to relieve pain. The local anesthetic medicine helps give you immediate pain relief. Corticosteroid medicines take longer to have an effect.
Within the spinal canal , an ESI is injected into the space around the spinal cord and nerve roots (epidural space). The injection does not go into the membrane (thecal sac) that contains the spinal cord and nerve roots.
ESIs sometimes are used to treat pain and inflammation from pressure on the spinal cord. ESI is usually not tried unless symptoms caused by lumbar spinal stenosis have not responded to other nonsurgical treatment.
Imaging tests, such as magnetic resonance imaging (MRI) or computed tomography (CT) scans, are usually done before you are given the injection. These tests are used to identify the exact location where nerve roots are being squeezed. During the injection, an X-ray machine (fluoroscope) is often used to guide placement of the needle.
Why It Is Used
An epidural steroid injection (ESI) may be tried when other nonsurgical treatments have failed to relieve severe leg pain from lumbar spinal stenosis.
The corticosteroids in an ESI can help provide relief from leg pain by reducing swelling and inflammation. Local anesthetics help relieve pain but do not reduce inflammation. Lidocaine can also help relieve pain quickly, before the corticosteroid has taken effect.
How Well It Works
Lumbar spinal stenosis may cause pain that radiates from the lower spine to the hips or down a leg. Epidural steroid injections (ESIs) are used for leg pain rather than back pain from lumbar spinal stenosis.
Steroid injections can help relieve pain for a short time (2 to 3 weeks) in some people. Experts do not know how well injections work over longer periods of time.1 Some people get enough pain relief that they can delay or no longer need surgery.
These injections may relieve symptoms and reduce inflammation but do not cure spinal stenosis.