Epidural Steroid Injections (ESI): What Your Surgeon Wants You to Know

Epidural steroid injections are a very common form of treatment for spine-related pain, but there are many misconceptions held by both patient and physicians about what they can and cannot do. I want to give an overview of the types of conditions for which an epidural steroid injection can be used, how they are performed, and what can be expected from them. I give a detailed analysis of epidural steroid injections in my book, The Spine Encyclopedia, if you are still looking for more answers after reading this article.

What conditions are Epidurals used to treat?

Spine physicians use epidural steroid injections to treat radiculitis (from the Latin radiculo, meaning “little root,” in reference to the nerve root, and -itis, meaning inflammation), a condition where a nerve exiting the spine is compressed and becomes inflamed and painful. Radiculitis occurs when a spinal nerve is compressed and triggers an intense inflammatory response that further sensitizes the nerve, making it irritable and easily triggered. This results in severe leg and low-back pain. When the condition worsens, radiculopathy can develop, resulting in numbness and weakness in addition to pain. Epidural steroid injections can be an option when more basic treatments such as physical therapy and oral medications have failed.

Common causes for nerve compression include intervertebral disc herniation, spondylolisthesis, and spinal stenosis. Lumbar disc herniations tend to be very painful and inflammatory and offer the best indication for epidural use. Epidurals are also effective for spinal stenosis and spondylolisthesis, but medical society recommendations are not as strong for these conditions. Epidurals may offer some relief for pure back pain caused by degenerative disc disease, but again, the evidence is not as strong as for radiculitis (1). Epidurals can be performed in both the cervical (neck) area and the lumbar spine (low back), but administration in the lumbar spine is much more common and generally considered safer.

Am I a candidate for an epidural steroid injection?

Typically, to be a candidate for an epidural steroid injection you should have symptoms of radiculopathy and radiculitis—namely, radiating pain to the buttocks, leg and foot from the low back. You should have an MRI or CT scan demonstrating nerve root impingement. Chronic narcotic use, smoking, and chronic pain syndromes all negatively affect epidural efficacy (2). Some people should not have epidurals under any circumstances, including those with an ongoing infection or rash over the injection site, or uncontrolled bleeding disorders. Steroids also commonly elevate blood sugar, so talk with your doctor if you have diabetes. If you have hepatitis c, liver disorder, or chronic immunosuppression, you may also not be a good candidate for epidurals (3). If you are allergic or are hypersensitive to contrast, local anesthetics, or steroid medications, you should not have epidural injections. If you have a condition that requires urgent surgery, such as severe spinal compression with worsening weakness and numbness, you should not have epidurals.

What are the risks of Epidurals?

Epidurals are very safe, and complications are exceedingly rare (2,4). However, minor or major complications can occur with epidurals. Minor complications can include bleeding, temporary increase in leg or back pain, or headache caused by spinal fluid leak. More serious adverse events include hematoma formation (bleeding around the injection site) or infection/abscess formation in the spine. In administering epidurals, physicians insert needles close to nerves and the spinal canal, so the possibility of neurologic injury exists, which can result in weakness or paralysis. Blood vessels are also at risk; in rare cases, injury can result in stroke. Thankfully, neurologic and vascular injuries are exceedingly rare (2).

Epidurals can increase the risk of infection following surgery if used too close to the time of a procedure. Thus, in most cases, you will need to wait at least 6 weeks after having an epidural to have any spine surgery (5).

How are Epidurals performed?

Epidural steroid injections refer to an injection performed with a long needle inserted into the epidural space within the spine. The epidural space is the area between the bone and nerves.  The injection typically contains an anti-inflammatory steroid medication such as dexamethasone or methylprednisolone and a local anesthetic (typically lidocaine and bupivacaine). Local anesthetics provide immediate pain relief by numbing the inflamed nerve. Steroid medications then work to stop the inflammatory process, which can desensitize the nerve and relieve radiculitis pain. The steroid is the component thought to be responsible for providing long-lasting relief, but results show that both components are important (6).  Epidural steroid injections are also usually preceded by the injection of iodine-based contrast, such as isovue 200 or omnipaque 240/300, to confirm needle placement.

An epidural can be performed in three ways: midline in the spine (intralaminar), through the side of the spine (transforaminal), or through the sacrum (caudal). Transforaminal epidurals are the most commonly used and considered the most efficacious approach because they target a specific area and side, whereas caudal and intralaminar injections are less specific (7).

In general, epidurals are performed in a procedure room or surgery center using x-ray guidance to ensure the needle is placed safely in the correct location. Sometimes you may be given sedation, but most epidurals are performed under local anesthesia. The doctor uses the x-ray machine to target the area where the inflamed nerve is located, and a small amount of contrast is injected to confirm. Here are some important things to remember before and after your epidural:

·      You need someone to drive you to and from your appointment for an epidural steroid injection.

·      You cannot take blood thinners for 3–7 days prior to your epidural, but discuss with your surgeon and medical doctor.

·      You should call your doctor immediately if you experience headache, worsening numbness, weakness, or new fevers or chills/signs of infection.

Epidural steroid injections are usually performed by a spine surgeon or qualified pain-management doctor. They may be used either “diagnostically” or “therapeutically.” Diagnostic injections are used to anesthetize specific nerves, or perform a so-called selective nerve root block. So, if your pain goes away after the injection, it can help the surgeon determine exactly where your pain is coming from and give more confidence that surgical intervention may help.

Therapeutic in this case just means that the epidural  is long lasting and offers durable symptomatic relief for months to years.

Are Therapeutic Epidural steroid injections effective?

Transforaminal epidural steroid injections are very effective at treating pain from lumbar disc herniations for up to 3–6 months following the injection. They can be helpful for acute lumbar disc herniations, but the evidence for treatment of chronic degenerative stenosis is less robust (4). Randomized controlled trials have shown that, compared to intramuscular steroid injections, epidural steroid injections are more effective in treating sciatic pain (8). In a study where all patients had already decided to undergo surgery to treat their lumbar radicular pain, epidural steroid injection prevented the need for lumbar decompression surgery in 20 of 28 patients (9).

When injections are used therapeutically, they are given in hope that they will treat the ongoing problem. Epidural steroid injections have been shown to reduce the level of pain by more than 50 percent in 63 percent of individuals with lumbar disc herniations, and pain reduction can last up to a year. The success rate in treating pain for spinal stenosis is slightly less, at around 50 percent (10). Injections do not cure mechanical problems such as disc herniations or stenosis in the spine. Instead, injections can relieve inflammation in the spine caused by these very painful conditions. Steroidal injections do not treat numbness or weakness caused by compressed nerves, nor do they shrink disc herniations or whisk away stenosis.

How long will an epidural last?

The duration of pain relief offered by epidurals differs from patient to patient and type of spinal problem. As stated above, epidurals are excellent for lessening acute inflammation. In some cases of chronic disc herniations, some of the inflammation will be burnt out, i.e. the chemicals which start the inflammation and pain will disappear, and epidurals will not be as effective in these cases. While epidurals offer great short-term pain relief for up to 6 months, 75 percent of patients will not get long-lasting relief, and 50 percent will ultimately require additional injections or surgery (11,12).

How many epidural steroid injections can I have?

Epidural steroid injections can be repeated every 3–4 months but are typically repeated only if they were initially successful (13). What this means is that if the injection worked great for you, and provided durable relief, it is worth repeating, assuming you do not have a problem that requires surgery. If there was no immediate or long-lasting effect from the steroid injection, it should not be repeated in the same place, but other locations may be considered (3). In the past, a series of three epidural steroid injections separated by several weeks were given, but this no longer the standard of care.

Conclusions:

Epidural steroid injections are a very safe and effective treatment for sciatic-type pain. They are useful to help the body resolve pain and can also be used diagnostically to help a surgeon target surgical procedures by confirming where your pain originates. They make sense for many patients who are suffering from spine-related pain. Although epidural steroid injections do not typically resolve mechanical problems of the spine, they are great at reducing inflammation and sciatica. For more information, check out my book, The Spine Encyclopedia.

References:

1.         Epidural Interventions in the Management of Chronic Spinal Pain: American Society of Interventional Pain Physicians (ASIPP) Comprehensive Evidence-Based Guidelines. Pain Phys. 2021 Jan 22;S1;24(1;S1):S27–208.

2.         Palmer WE. Spinal Injections for Pain Management. Radiology. 2016 Dec;281(3):669–88.

3.         William J, Roehmer C, Mansy L, Kennedy DJ. Epidural Steroid Injections. Physical Medicine and Rehabilitation Clinics of North America. 2022 May;33(2):215–31.

4.         Transforaminal Epidural Steroid Injections: A Systematic Review and Meta-Analysis of Efficacy and Safety. Pain Phys. 2021 Jan 22;S1;24(1;S1):S209–32.

5.         Kreitz TM, Mangan J, Schroeder GD, Kepler CK, Kurd MF, Radcliff KE, et al. Do Preoperative Epidural Steroid Injections Increase the Risk of Infection after Lumbar Spine Surgery? Spine. 2021 Feb;46(3):E197–202.

6.         Friedly JL, Comstock BA, Turner JA, Heagerty PJ, Deyo RA, Sullivan SD, et al. A Randomized Trial of Epidural Glucocorticoid Injections for Spinal Stenosis. N Engl J Med. 2014 Jul 3;371(1):11–21.

7.         Pandey RA. Efficacy of Epidural Steroid Injection in Management of Lumbar Prolapsed Intervertebral Disc: A Comparison of Caudal, Transforaminal and Interlaminar Routes. J Clin Diagn Res. 2016 Jul;10(7):RC05–RC11.

8.         Ghahreman A, Ferch R, Bogduk N. The Efficacy of Transforaminal Injection of Steroids for the Treatment of Lumbar Radicular Pain. Pain Med. 2010 Aug;11(8):1149–68.

9.         Riew KD, Yin Y, Gilula L, Bridwell KH, Lenke LG, Lauryssen C, et al. The Effect of Nerve-Root Injections on the Need for Operative Treatment of Lumbar Radicular Pain: A Prospective, Randomized, Controlled, Double-Blind Study*. Journal of Bone and Joint Surgery-American Volume. 2000 Nov;82(11):1589–93.

10.       Smith CC, McCormick ZL, Mattie R, MacVicar J, Duszynski B, Stojanovic MP. The Effectiveness of Lumbar Transforaminal Injection of Steroid for the Treatment of Radicular Pain: A Comprehensive Review of the Published Data. Pain Medicine. 2020 Mar 1;21(3):472–87.

11.       Kennedy DJ, Zheng PZ, Smuck M, McCormick ZL, Huynh L, Schneider BJ. A Minimum of 5-Year Follow-Up after Lumbar Transforaminal Epidural Steroid Injections in Patients with Lumbar Radicular Pain Due to Intervertebral Disc Herniation. Spine J. 2018 Jan;18(1):29–35.

12.       Kwak S, Jang SH, Chang MC. Long-Term Outcomes of Transforaminal Epidural Steroid Injection in Patients with Lumbosacral Radicular Pain According to the Location, Type, and Size of Herniated Lumbar Disc. Pain Pract. 2021 Nov;21(8):836–42.

13.       Murthy NS, Geske JR, Shelerud RA, Wald JT, Diehn FE, Thielen KR, et al. The Effectiveness of Repeat Lumbar Transforaminal Epidural Steroid Injections. Pain Med. 2014 Oct;15(10):1686–94.