The joint where your spine meets your pelvis (the sacroiliac, or SI, joint) sits on each side of your lower back, where the base of your spine locks into your hip bone. Built more like a support beam than a hinge, it barely moves, but it carries your whole upper body’s weight every time you stand, twist, or reach for something.

It’s held together by tight ligaments rather than free movement, so when it gets irritated, the pain doesn’t stay confined to one spot.

The sacroiliac joint injection places medication directly into your sacroiliac joint to reduce inflammation and pain. Our back pain treatments hub covers the full range of causes and options behind low back pain.

Key Takeaways

• The injection places medication directly into your sacroiliac joint to reduce inflammation and pain.
• Doctors use either diagnostic injections to confirm the problem or therapeutic injections to provide relief.
• The procedure takes just minutes and uses imaging guidance to place the needle in the right spot.
• Relief typically lasts weeks to months, but results vary from person to person.
• Some patients experience temporary soreness after the injection, but serious side effects are uncommon.

What the injection does

A thin needle, guided by live x-ray (your doctor calls this fluoroscopy), goes straight into the joint where your spine meets your pelvis. Once it’s in place, your doctor delivers two things through it: a numbing medicine and an anti-inflammatory medication.

This is a minimally invasive procedure, done through a tiny puncture rather than a surgical cut, and the whole thing runs under 15 minutes with you awake the entire time.

Most patients walk out the same day. The shot works two ways at once: it confirms whether this joint is actually producing your pain, and it reduces the inflammation so your body can start settling down.

That joint sits wedged tightly between muscles, ligaments, and nerves, and pain from it travels into your buttock, your groin, sometimes all the way down your leg. That’s a big part of why it gets mistaken for a hip problem or a disc problem in the first place.

The numbing medicine answers the diagnostic question within hours: if your usual pain drops sharply, this joint is your source. The anti-inflammatory medication that rides along with it works more like a dimmer than a switch, easing the swelling that’s actually been driving the pain over the days that follow.

Diagnostic vs. Therapeutic Injections

The first shot confirms the diagnosis. The second, if you need it, delivers lasting treatment. Most patients get real value from both in a single visit.

The numbing medicine goes in, and then you get up and do the movements that normally set off your pain, standing from a chair, twisting, climbing a step. Doctors count it as confirmation when pain falls by at least 75% while you’re doing those activities, which tells your doctor this joint is the culprit.

The same logic drives a nerve block treatment overview (numbing medicine placed at a specific nerve to block its pain signal) anywhere in the body: numb first, then treat.

Adding the anti-inflammatory medication to that same injection is what stretches relief from a few hours into weeks or months.

A single injection done without that controlled numbing check can read as a positive result about 20% of the time even when the joint isn’t actually the problem. So doctors sometimes ask for a second, confirming block before recommending anything longer-lasting. It protects you from committing to bigger treatment based on a fluke.

That second block is scheduled as its own appointment. Ask your doctor’s office how much time they want between the two, and our billing office can tell you how each visit will be billed.

Signs you may be a candidate

The pattern that brings most people in looks like this: pain on one side, below the belt line, that gets worse sitting, standing up, or rolling over at night, and hasn’t budged with therapy or pills.

• One-sided pain that stays on the same side of your low back or buttock
• Pain that flares with position changes, such as sitting too long, climbing stairs, or rising from a chair
• Pain reaching into the groin or thigh, though it typically stops above the knee

Injections into this joint are used for pain in the low back, groin, buttock, and leg caused by inflammation around the joint’s nerves.

Other conditions can produce a similar pattern, and here’s how they differ. Sciatica tends to run all the way down to the foot.

Hip arthritis often shows up as groin pain that moves with the leg when you turn it. A bulging disc can mimic several of these patterns at once, and your doctor sorts through that overlap with a hands-on exam and a numbing block.

Once the joint is identified as the source, it helps to know what set it off. A fall onto the buttock or a car accident can jar the joint directly. Pregnancy loosens the ligaments that hold it steady, a pattern covered in more depth in our piece on female back pain causes.

Arthritis wears down the joint surface over years, and a previous spine surgery can shift how you load one side without you noticing. Causes on record include arthritis, gout, psoriasis, fracture, infection, pregnancy, and prior spine surgery.

Before reaching for a needle, doctors work through hands-on exam moves that stress the joint, imaging to rule out other spine sources, and a real trial of physical therapy.

You start with your primary care doctor or come in directly, and imaging gets ordered to rule out other causes. From there we can walk you through whether a diagnostic injection makes sense.

Call (928) 771-8477 and we’ll help sort out the right first step for you.

What goes into the shot

Three things go into the syringe, and only two of them are actual medicine. In the order they matter to you:

• A numbing anesthetic gives you the fast answer
• An anti-inflammatory medication (a corticosteroid) works over the days that follow
• A contrast dye rounds out the mix without treating anything at all

The standard kit uses a numbing agent like lidocaine or bupivacaine, an anti-inflammatory such as triamcinolone or methylprednisolone, and dye to confirm placement. Our cortisone injection overview breaks down how that anti-inflammatory medication works once it’s in the joint, and our explainer on the nerve block procedure covers how the numbing agent quiets a pain signal.

On the live x-ray screen, your doctor watches the dye spread and pool, confirming the needle tip is truly sitting inside the joint space before either medicine goes in.

A dye allergy, blood thinners, and diabetes all affect how your doctor plans the medications, so the office needs to hear about each of these before the day of your shot.

How to Prepare

Everyone should tell the doctor about any blood thinners they take, since those may need to be paused ahead of time. Skip alcohol and smoking beforehand, and pause your diabetes medications if instructed. Wear loose clothing, and plan to arrive early so there’s time for check-in and monitoring afterward.

Sedation isn’t part of a standard visit, since you stay awake so you can report how your pain responds. If sedation is planned for you, those instructions add two more steps: stop eating and drinking the night before, and arrange a ride home.

If sedation isn’t planned, neither step applies and you can eat normally and drive yourself. Ask your doctor’s office whether sedation applies to your appointment so you know which set of instructions to follow, and raise it there if you’re anxious about the needle.

An allergy to the medicines being used, an active infection in the joint, or a growth at the injection site are hard stops, no exceptions. Blood thinners, pregnancy, and poorly controlled diabetes don’t automatically cancel the shot, but your doctor weighs the risk against the benefit before moving forward.

Write down your pain scores during the movements that usually set it off, sitting too long, standing up, turning over in bed. Bring that list with you. It gives your doctor a real baseline to compare against once the injection is done.

What happens during the procedure

You’ll check in, have your vitals taken, then lie face down on the table while the skin over the joint gets cleaned and numbed. From there, your doctor guides a thin needle into the joint using live x-ray, injects a small amount of contrast dye to confirm placement, then delivers the numbing medicine and anti-inflammatory medication. A bandage goes on, and you’re done.

Most of the visit is setup. The needle placement and medicine delivery usually take under 15 minutes total, but getting you positioned, prepped, and confirmed on the x-ray takes longer than the shot does. After that, you’ll rest in recovery for 30 minutes to an hour while staff watch for any reaction before sending you home.

Interventional radiology physicians (a specialty that uses imaging to guide procedures through tiny punctures) perform this procedure. They don’t go by feel, since the joint sits too deep in your pelvis to find reliably by hand.

Image guidance like this runs through the rest of our interventional radiology services, from this injection to a peripheral angiogram procedure in the vessels of the leg. Without image guidance, a needle placed blind lands inside the joint only 12% to 22% of the time.

How much does it hurt?

Most people feel a quick sting, then pressure, not sharp pain. Your doctor numbs the skin first, so the sting fades fast. As the needle advances toward the joint, you’ll feel pressure rather than a stabbing sensation, and once the medicine goes in, there’s often a brief, deep ache as the joint fills. The whole thing takes just a few minutes.

Your report of how much your pain drops afterward, while you do the movements that normally hurt, is part of what confirms the diagnosis. That report is also why most people stay awake for it and don’t need sedation at all. If sedation is used, you’ll need a driver.

Soreness at the site can last a day or two, closer to a deep bruise than the pain that brought you in.

The first 24 hours

The first six hours or so usually feel unusually good, and then the pain creeps back: the numbing medicine gives you strong, fast relief right after the shot, but it fades around the six-hour mark. As it wears off, pain can return before the anti-inflammatory medication picks up the work over the next one to three days.

Most people drive themselves home the same day, unless sedation was used, and walk out under their own power. There are generally no major activity limits, and most patients are back at a desk job by the next morning.

For the rest of the injection day, keep things easy:

• Ice the area rather than using heat
• Skip heavy lifting
• Walk and handle desk work as tolerated
• Ease back into golf, hiking, or yard work over the coming days
• Resume physical therapy on your therapist’s schedule

There’s no fixed day count for when golf or yard work fully comes back, since doctors and patients track how your own pain settles instead of following a calendar. The safest move is easing in gradually and asking your doctor’s office for a timeline specific to you.

Pain that keeps climbing instead of settling, a fever, or spreading numbness isn’t something to wait out. Call your doctor’s office the same day if you notice any of those.

How long relief lasts

Relief typically ranges from several weeks to several months, and it varies quite a bit from person to person. Most people feel some relief right after the shot, with studies showing 50% to 80% of patients getting pain relief immediately.

In one group of 75 patients, 57% had their pain cut at least in half at 48 hours, 55% still did at one week, and 35% still did at three months. Those windows sit in the same range as reported cortisone shot duration and reported nerve block duration elsewhere in the body.

In that same group, patients who needed a second injection typically waited about 11 months before coming back, and only two of the 75 ever needed a fourth. That’s a meaningful stretch of relief for most people, even when it isn’t permanent.

Doctors typically cap injections at three to four per joint per year. Repeated doses too close together can weaken the cartilage, ligaments, and bone around the joint and raise blood sugar, so doctors space doses to protect you.

Three things commonly cut relief short. Going straight back to heavy lifting or hard yard work puts the same load right back on the joint. An untreated hip or spine problem on that same side keeps causing pain independent of the injected joint. And skipping physical therapy means missing the chance to build strength while pain is low.

About half of the patients in that same study paired their injections with physical therapy, a combination that tends to help the relief last.

Side effects and risks

Most people who get this shot deal with something minor for a day or two, and the serious complications are uncommon. You might notice soreness where the needle went in, a brief flare of pain, or a moment of feeling lightheaded right after.

People with diabetes sometimes see a short bump in blood sugar. All of that tends to pass on its own.

The rarer risks include infection in the joint, bleeding, nerve irritation, or the medication reaching a blood vessel instead of the joint space. To avoid hitting a blood vessel, your doctor watches the needle on live x-ray the entire time instead of working by feel.

Call your doctor the same day if you notice any of the following:

• A fever over 100.4
• Spreading redness or drainage at the injection site
• Severe pain that won’t ease up
• New weakness in your leg
• Any loss of bladder or bowel control

Cost and coverage

Without insurance, expect to pay around $1,400 on average for one image-guided injection, though the number moves depending on your facility, the imaging used, and whether sedation is involved.

Medicare covers this injection when your doctor documents that it’s medically necessary, usually after conservative treatment hasn’t worked. Conservative treatment means the non-procedural steps described earlier: a real trial of physical therapy and medication. Most commercial insurance plans follow that same rule.

Whether your diagnostic shot and a second confirming block get billed separately from a treatment injection, and how each counts against your plan’s yearly limit, isn’t something with one universal answer. Our billing office can check your specific plan before you schedule.

Before you schedule, ask your billing office:

• What’s the facility fee?
• Where do I stand on my deductible?
• How many injections does my plan cover this year?

If the injection doesn’t help

When a shot doesn’t work, your doctor uses that result to narrow down where your pain is coming from. This joint may never have been the source, which sends the search to your hip or the rest of your spine. Or it’s the source and needs a different follow-up plan.

A repeat injection paired with physical therapy is often the first move, one of several approaches in our lower back pain treatment guide. Radiofrequency ablation (using heat to quiet the small nerves feeding the joint) is a longer step for people who keep getting short-lived relief.

Joint fusion, permanently joining the two bones, is reserved for the smaller group who keep proving the joint is the problem, and more than 4 out of 5 of those patients get lasting relief.

Using your pain-free window for targeted therapy tends to stretch how long relief holds, though the published evidence on repeat injections and heat treatment is still limited.

Your doctor sits down with you, your imaging, and your injection result to map out the next step together.

Call (928) 771-8477 to Find Out What’s Really Driving Your Pain

Pain that keeps coming back to one side of your low back and buttock has a locatable source, and one image-guided shot can often point to that source and calm it at the same time.

Call (928) 771-8477 to schedule your consultation, find out whether this joint is what’s been causing your trouble, and get back to the golf, hiking, or yard work you’ve been missing.

Frequently Asked Questions

Does a sacroiliac joint injection hurt?

Most people feel a quick sting from the numbing shot, then pressure as the needle goes in, not sharp pain. A deep ache can follow briefly as the joint fills with medicine, and the whole thing takes just a few minutes.

Who performs sacroiliac joint injections?

Interventional radiology physicians perform this procedure. They use live x-ray guidance to place the needle, since the joint sits too deep in your pelvis to find reliably by hand or feel.

What are the contraindications for a sacroiliac joint injection?

An allergy to the medicines used, an active infection in the joint, or a growth at the injection site are hard stops. Blood thinners, pregnancy, and poorly controlled diabetes need your doctor’s judgment first.

How long until the injection starts working?

The numbing medicine gives fast relief within hours, then wears off around six hours later. The anti-inflammatory medication takes over next, usually starting within 24 to 72 hours and reaching full effect within a week.

Can I drive or return to work after the injection?

Yes, most people drive themselves home the same day and return to a desk job by the next morning. There are generally no major activity limits unless you had sedation, which requires a driver.

How does SI joint pain differ from sciatica or a bulging disc?

SI joint pain usually stays one-sided and worsens with sitting, standing up, or rolling over in bed. Sciatica tends to run all the way down to the foot, while a bulging disc can mimic several patterns at once.

How much does a sacroiliac joint injection cost without insurance?

Expect to pay around $1,400 on average for one image-guided injection. The price depends on your facility, the imaging used, and whether sedation is involved, so ask about self-pay rates upfront.