Spinal Injections for Diagnosing and Treating Pain

Medically reviewed by

on November 17, 2020

A spinal injection is an invasive procedure used for both diagnosing and treating low back pain. The purpose of a spinal injection is to deliver medicine directly to the specific site of pain.

When you have a diagnostic injection, the goal is to find out whether a specific medication relieves your pain. If it does so in the area your doctor suspects is the source, based on your physical exam and medical history, they can confirm the diagnosis. Pain relief from diagnostic injections is generally temporary—usually lasting just a few hours.

When you have an injection as a treatment, the relief tends to last longer.

Here are four commonly administered spinal injections.

Selective Nerve Root Block

Spinal column, illustration — BSIP / UIG / Getty Images

Selective nerve root blocks are one of the most commonly given spinal injections. They are used to treat or diagnose back and/or leg pain resulting from damaged nerve roots, a collection of nerves that branch off the main spinal cord all along your spine. A compressed or irritated nerve root can result in leg pain that most people call sciatica, although its technical name is radiculopathy.

A 2013 guidelines report by the American Society of Interventional Pain Physicians (ASIPP) points out that although the evidence for accuracy of diagnostic selective nerve root blocks is limited, they are recommended for patients whose pain source is uncertain and occurs on multiple levels of the spine.

Lumbar Facet Joint Nerve Blocks

Human Spine, Pelvis, Chiropractic, Orthopedic, Medical Model, Heathcare, Isolated — 1Photodiva / Getty Images

If, based on a physical exam, your doctor suspects your pain is coming from the joints at the back of your spine, they may recommend trying a facet injection. Facet joints are connections between the bones of the spine on each side and each vertebral level. They add integrity to the spine by limiting excessive movement. The facet joint is a common site for spinal arthritis.

ASIPP guidelines state that evidence for diagnostic lumbar facet joint nerve blocks is good: The standard is 75 to 100 percent pain relief, and they are recommended in patients who've been diagnosed with facet joint pain.

But beware: Some research shows that for the most part, facet joint injections for pain (not diagnosis) are not proven long-term pain relievers. A facet injection alone is not likely to give you lasting results.

Injections into Your Sacroiliac Joints

Doctor pointing to Sacroiliac Joint on skeleton — Jan-Otto / Getty Images

Sacroiliac joint injections include intra-articular steroid injections (also the type given for painful facet joints) and periarticular injections (intra-articular means "inside the joint"; periarticular means "around the joint"). Botox and steroids are commonly used for periarticular injections.

Only limited evidence supports the use of the intra-articular and periarticular types of sacroiliac injections. However, as a diagnostic tool, intra-articular sacroiliac joint injections with local anesthetics that relieve 75 to 100 percent of your usual pain have good science behind them, according to ASIPP.

Another treatment option is pulsed or conventional radiofrequency neurotomy. Radiofrequency neurotomy introduces heat into the joint to interrupt nerve pain transmission.

A review study in 2014 showed that radiofrequency treatments significantly reduce pain in the short term, but more evidence is needed to show whether treatments have long-term benefits.

Epidural Steroid Injections

If you have a herniated disc or disc radiculitis, your doctor may suggest an epidural injection. A spinal epidural injection delivers steroid medication into the epidural space, an area between the spinal cord and the vertebral canal and near the very sensitive spinal cord.

For herniated disc or disc radiculitis, ASIPP recommends one of three approaches: caudal, interlaminar or transforaminal. These are also recommended for pain from stenosis. (By the way, these fancy words refer to the direction and location of the needle insertion.)

Your doctor might also suggest an epidural injection if you have
discogenic pain, which arises from inside the disc rather than from an injury or herniation. In this case, either interlaminar or caudal epidural injections are recommended.