Facet Joint Injection

Overview

Facet joints are the small paired joints located at the back of each spinal segment that let the spine bend, twist, and extend. Like any joint, they can become a source of pain from arthritis, wear and tear, or injury, producing pain that is often worse with backward bending, twisting, or prolonged standing. A facet joint injection places a small amount of local anesthetic, sometimes combined with a steroid, directly into or around the joint using fluoroscopic (real-time X-ray) guidance to confirm accurate needle placement.

The procedure serves two related purposes. As a diagnostic tool, it helps confirm or rule out the facet joint as the actual source of pain, since imaging alone often cannot prove which structure is generating symptoms. As a therapeutic tool, the anti-inflammatory steroid component can calm irritation within the joint and provide longer-lasting relief, though this effect is more variable than the diagnostic value of the anesthetic.

When it's recommended

Facet joint injections are typically considered for chronic neck or back pain that is worse with extension or rotation, has not responded adequately to physical therapy, activity modification, and medication after several weeks, and is not explained by a clear disc herniation or nerve compression on imaging. They are also used when exam findings, such as pain reproduced by twisting or arching the spine, point toward the facet joints rather than the discs or nerve roots as the likely pain generator.

Because no single exam finding or imaging result reliably confirms facet joint pain on its own, the diagnostic injection itself is often the deciding test: if pain relief closely tracks the expected duration of the local anesthetic used, the facet joint is considered a likely source and further facet-directed treatment is reasonable. If relief does not occur, the search for the cause of pain typically shifts elsewhere.

How it works

The procedure is done with the patient lying face down or on their side, with the skin cleaned and numbed with local anesthetic. Using fluoroscopic guidance, the physician advances a thin needle to the targeted facet joint or joints and confirms placement with a small amount of contrast dye before injecting the anesthetic, with or without a steroid. The whole procedure usually takes fifteen to thirty minutes, and patients are monitored briefly afterward before going home the same day.

Many pain specialists now favor a related technique, the medial branch block, which numbs the small nerves supplying the facet joint rather than injecting the joint itself. Medial branch blocks are considered a more reliable diagnostic step, and a strong, reproducible response on two separate occasions is generally what determines candidacy for radiofrequency ablation (RFA), a longer-lasting treatment that uses heat to disable those same nerves.

Preparing for the procedure

Preparation typically involves a review of current medications, since blood thinners, aspirin, and certain supplements often need to be paused beforehand under your provider's guidance, and screening for allergies to contrast dye, local anesthetics, or steroids. Patients are usually asked to arrange a ride home, since mild sedation may be offered, and to eat a light meal beforehand unless instructed otherwise. Keeping a brief pain diary in the hours after the injection, noting when and how much relief occurs, is one of the most useful things a patient can do, since it directly informs the diagnostic value of the procedure.

Recovery and aftercare

Most patients can resume normal activity the same or next day, though some soreness at the injection site for a day or two is common. If a local anesthetic alone was used, any significant pain relief is expected to be short-lived, typically hours, which is the intended diagnostic signal rather than a sign the treatment failed. If a steroid was included, therapeutic benefit, if it occurs, tends to build over several days and can last weeks to months.

Patients are usually asked to avoid strenuous activity for a day or two and to track their pain response closely, since this information guides the next step, whether that is repeating the injection, moving to medial branch blocks, or considering radiofrequency ablation if relief has been clear and reproducible.

Risks and considerations

Facet joint injections are generally low risk, but potential complications include infection, bleeding, an allergic reaction to contrast or medication, and temporary numbness or weakness if anesthetic spreads to a nearby nerve. Steroid injections carry additional considerations, including transient facial flushing, temporary blood sugar elevation in patients with diabetes, and a cumulative dose limit that restricts how often they can be safely repeated at the same level.

The main limitation is diagnostic uncertainty from placebo response, which is why many practices require a positive response on two separate blocks, sometimes using anesthetics of different durations, before considering a joint confirmed as a pain source. Facet injections are not typically effective for pain caused primarily by disc herniation, nerve root compression, or spinal instability, so accurate patient selection matters as much as the technical performance of the injection itself.