Epidural steroid injections (ESIs) are a common treatment option for many forms of low back pain and leg pain. The goal of the injection is pain relief; at times the injection alone is sufficient to provide relief, but commonly an epidural steroid injection is used in combination with a comprehensive rehabilitation program to provide additional benefit.
Disc prolapse or facet joint arthropathy as well as many others provoke an inflammation that in turn can cause significant nerve root irritation and swelling. The drugs are delivered into the epidural space of the spine, which is the area between the protective covering (dura) of the spinal cord and nerves and the bony vertebrae. Unfortunately, the injection does not make a herniated disc smaller; it only works on the spinal nerves by flushing away the proteins that cause swelling.
Most patients can walk around immediately after the procedure. Patients may experience pain from the procedure for up to 14 days, but this is generally due to the residual effects of the nerve ablation or muscle spasm. Patients are often up and around and back to work 24 to 72 hours after the procedure. Pain relief is typically experienced within 10 days, although relief may be immediate for some patients and take up to three weeks for others.
The effect of the injection tends to be temporary – providing relief from pain for a few weeks up to one year or even more.
An epidural injection is a relatively safe procedure with minimal risk of complications. The complications reported in the literature include a temporary increase in nerve pain, neuritis, neuroma, localized numbness, infection, allergic reaction to medications used during the procedure, and/or lack of pain relief (in less than 30% of patients).