Sacroiliac Joint Injections for Back Pain: 2026 Guide

Sacroiliac joint injections calm inflammation at the base of the spine and confirm, in one visit, whether the SI joint is actually the source of a patient’s low back pain. This guide walks through what the procedure involves, what happens step by step, and what to expect from Hudson Pain and Spine in 2026.

TL;DR

• Sacroiliac joint injections for back pain deliver corticosteroid and anesthetic directly into the joint under imaging guidance.
• Research links the SI joint to 15% to 30% of chronic low back pain cases, often mistaken for disc or facet pain.
• A single injection typically brings 3 to 6 months of relief and doubles as a diagnostic test.
• Dr. Saurabh Dang performs SI joint injections at Hudson Pain and Spine locations in Englewood, Woodland Park, and Edison, NJ.
• Patients who respond well to injections are often candidates for radiofrequency ablation for longer-lasting relief.

Why this matters

Low back pain gets blamed on the disc or the facet joints almost by default, but the sacroiliac joint, where the spine meets the pelvis, is a common and frequently missed source. Studies in pain medicine literature put the SI joint’s share of chronic low back pain cases between 15% and 30%, which means a meaningful slice of patients spend years chasing the wrong diagnosis.

The joint sits low, near the dimples above the buttocks, and pain from it often mimics hip pain, sciatica, or lumbar disc pain. That overlap is exactly why an injection matters: it treats inflammation and it tells the physician, with real precision, whether this joint is the actual problem. At Hudson Pain and Spine, that diagnostic clarity shapes the entire treatment plan going forward.

What you’ll need

• A clinical exam and imaging review — X-ray, MRI, or CT to rule out disc herniation or facet arthritis as the primary driver.
• A referral or direct consult with a board-certified interventional pain specialist who performs image-guided joint injections.
• A pain diary or symptom log covering the two weeks before the visit — location, triggers, and what movements worsen it.
• A driver for the appointment day, since sedation or numbness can affect reflexes for a few hours.
• Insurance verification completed ahead of time, since most plans require documented conservative treatment first.
• Comfortable, loose clothing that allows access to the lower back and hip area during the procedure.

Patients who’ve already tried physical therapy or oral anti-inflammatories without relief are the strongest candidates. Those still early in conservative care may be better served starting with options covered in the guide to candidates for epidural steroid injections, which treats a different but sometimes overlapping source of pain.

The steps: how sacroiliac joint injections relieve low back pain

1. Confirm the diagnosis with a physical exam

The physician tests specific movements, like the FABER test and thigh thrust, that stress the SI joint without loading the spine directly. Reproducing the patient’s exact pain pattern during these maneuvers narrows the diagnosis before any needle is involved. Skipping this step is the single biggest reason injections underperform, since a joint that isn’t actually inflamed won’t respond to a steroid regardless of technique.

2. Review imaging to rule out competing causes

MRI or CT confirms there isn’t a herniated disc, spinal stenosis, or advanced facet arthritis producing the same symptoms. This matters because treating the wrong structure wastes the injection and delays real relief. Patients with imaging suggesting disc involvement are often redirected toward options in the guide on treating a herniated disc without surgery.

3. Position the patient and prep the injection site

The patient lies face down on the procedure table, and the skin over the SI joint is cleaned and numbed with a local anesthetic. This step takes two to three minutes and causes only a brief pinch, not the discomfort of the injection itself. Positioning accuracy here determines whether the needle reaches the joint on the first pass.

4. Guide the needle with fluoroscopy or ultrasound

Real-time imaging lets the physician track the needle into the joint capsule, a target that’s roughly the width of a pencil and impossible to hit reliably by feel alone. Contrast dye is often injected first to confirm placement inside the joint space rather than the surrounding tissue. This is the step where fellowship training in interventional techniques shows up most, since imprecise placement is the top reason patients report weak or short-lived relief.

5. Deliver the corticosteroid and anesthetic mixture

Once placement is confirmed, a combination of corticosteroid and numbing medication is injected directly into the joint. The anesthetic works within minutes and gives an immediate read on whether the SI joint is the pain generator; the steroid’s anti-inflammatory effect builds over the following days. Most injections take less than 15 minutes start to finish.

6. Monitor immediately after the injection

Patients rest for 15 to 20 minutes and report how much of their usual pain has changed. A drop of 50% or more in that window is considered a positive diagnostic response and strongly predicts the joint is the true source. No change at all points the team back toward disc, hip, or facet causes instead.

7. Track relief over the following weeks

The steroid effect typically builds over three to five days and can hold for 3 to 6 months, though duration varies by how much inflammation was present. Patients keep a short symptom log during this window to give the physician clear data for the follow-up visit. This log is what separates a one-time fix from a real long-term plan.

8. Plan the next step based on response

Strong, lasting relief may mean repeating the injection when symptoms return, while a good but short-lived response often points toward radiofrequency ablation of the nerves feeding the joint. Details on that longer-lasting option are in the guide to radiofrequency ablation for chronic low back pain.

Troubleshooting: common problems and fixes

• Soreness at the injection site for 24 to 48 hours. This is expected and usually resolves with ice and acetaminophen; it isn’t a sign the injection failed.
• No pain relief at all. This usually means the SI joint wasn’t the true pain source, and imaging or exam findings should be revisited before trying again.
• Relief lasts only a few weeks instead of months. This can still confirm the diagnosis correctly while pointing toward radiofrequency ablation for a longer-term fix.
• Pain flares before it improves. A temporary steroid flare in the first two days is common and typically settles within 72 hours.
• Numbness or weakness in the leg after the procedure. This is almost always from the local anesthetic and resolves within a few hours; it should not persist past the day of the injection.
• Return of pain months later after good initial relief. This is normal joint behavior, not procedure failure, and a repeat injection or ablation is usually the next conversation.

Talk to a pain specialist in NJ

Schedule an evaluation for sacroiliac joint pain with Hudson Pain and Spine.

Book a consult

Tools and resources

• Physical exam findings and imaging reports, brought to the first consultation
• A symptom log tracking pain location, intensity, and triggers over two weeks
• Guidance on low-impact exercises for chronic low back pain to support recovery between injections
• A plan for driving and activity restrictions on procedure day
• Insurance documentation showing prior conservative treatment, if required by the plan

What to do next

Patients who get strong but short-lived relief from a diagnostic injection are frequently candidates for a longer-term nerve procedure. Review the guide on radiofrequency ablation for facet joint pain to understand how that next step compares in terms of relief duration and recovery.

FAQ

What are sacroiliac joint injections for back pain?

Sacroiliac joint injections for back pain deliver corticosteroid and anesthetic medication directly into the SI joint under imaging guidance to reduce inflammation and confirm the diagnosis. The procedure takes under 15 minutes and doubles as both treatment and diagnostic test.

How long does relief last after an SI joint injection?

Relief typically lasts 3 to 6 months per injection, depending on how much inflammation was present in the joint. Patients with shorter relief windows are often good candidates for radiofrequency ablation instead.

Is an SI joint injection painful?

Most patients feel a brief pinch from the local anesthetic and mild pressure during the injection itself, not sharp pain. Soreness at the site for 24 to 48 hours afterward is common.

How do doctors know if the SI joint is causing my back pain?

A positive diagnostic response is a 50% or greater drop in pain within 15 to 20 minutes of the injection, since the anesthetic acts immediately. This response confirms the SI joint as the pain generator rather than the disc or facet joints.

Can SI joint injections be repeated?

Yes, injections can be repeated when relief fades, though most physicians limit them to a few per year to avoid excess steroid exposure. Patients needing frequent repeats are usually moved toward radiofrequency ablation.

Who is a good candidate for sacroiliac joint injections?

Good candidates have low back pain concentrated near the dimples above the buttocks, a positive physical exam for SI joint stress tests, and imaging that rules out significant disc or facet disease. Patients who haven’t responded to physical therapy or oral medications are typically prioritized.

Do I need a referral for SI joint injections in New Jersey?

Requirements vary by insurance plan, but many patients can consult directly with an interventional pain specialist without a referral. Hudson Pain and Spine sees patients from Bergen, Passaic, and Middlesex counties at offices in Englewood, Woodland Park, and Edison.

What happens if the injection doesn’t work?

No change in pain after the injection usually means the SI joint isn’t the primary source, prompting a review of disc, hip, or facet joint causes instead. This is a normal and useful diagnostic outcome, not a failed procedure.

One last thing

The most overlooked detail in SI joint injections isn’t the needle, it’s the 15-minute window right after the injection. That’s when the anesthetic gives its clearest, most honest read on whether the joint is truly the source of the pain, before inflammation or guarding can muddy the response. Patients who track that window carefully, rather than judging relief days later, give their physician the sharpest data for deciding between a repeat injection and radiofrequency ablation.

Related guides

• Best low-impact exercises for chronic low back pain
• How to return to work safely after a pain procedure