Are Trans-Foraminal Lumbar Injections Better Than Interlaminar Epidural Injections?

Epidural steroid injections are a very effective treatment for pain management and patients with radiculopathy due to nerve root inflammation. Placing steroid medication around the nerve root that is either being compressed from a herniated disc or chemically inflamed can help significantly with pain reduction and potentially surgery avoidance. They do not "fix" the problem, they simply reduce the inflammation, thereby reducing pain.

When a patient receives an epidural steroid injection, the pain relief that is the result may allow that individual to then perform physical therapy, chiropractic treatment, and/or undergo spinal decompression treatment. Prior to the injection, the patient may be in so much pain that it may not be possible to participate in these treatments.

Most studies on epidural steroid injections that have been performed involved the interlaminar approach with the injections. The newer type of injections, referred to as trans-foraminal, have not been the subject of a heavy amount of research. A lot of the initial research on epidural steroid injections was done with the inter-laminar variation of the injections.

One of the issues with these initial studies was that they were not performed using a real time x-ray guidance machine, called a fluoroscopy. Unfortunately, there was at least a 40% miss rate with these injections, so whether or not the studies' injections were accurate is questionable.

Interlaminar injections place the steroid medication in the back part of the epidural space. The newer type of epidural injection, trans-foraminal injections, places the steroid medication farther out the region where the nerve root is trying to exit from the spine. This is typically the area where he herniated disc pushes on the nerve root, creating a pinched nerve situation. As mentioned, the steroid doesn't make the disc herniation "un-herniate" in any way.

There have been some recent studies looking at inter-laminar epidural steroid injections versus the transforaminal variety. Essentially what the studies are showing is that both of the injection types are effective, and equally so. Functional outcomes appear to be equivalent as well. The improvements allow patients to undergo therapy better, work more, and socialize without the unbearable pain.

One of the consistent findings in the recent literature is that epidural steroid injections overall are very effective through either techniques for improving the symptoms from radiculopathy due to a herniated disc. The overall effectiveness is greater than 75%, and some studies have shown upwards of a 90% response rate, particularly in those patients who are symptomatic for less than three months.

One of the overlying conclusions here is that either technique is effective for radiculopathy, but that real-time x-ray guidance should be incorporated to make sure that the epidural steroid medications are being placed most accurately for the benefit of the patient.