Understanding the SI Joint Injection
What is a sacroiliac joint injection?
The sacroiliac (SI) joints connect the lower spine to the pelvis. An SI joint injection places medication into the joint using live X-ray guidance (fluoroscopy) and contrast to confirm accurate needle position.
SI joint pain is commonly felt below the beltline and may extend into the buttock, hip, groin, or upper thigh. The injection may be performed on one side or both sides when clinically appropriate.
Diagnostic or therapeutic — which am I having?
| Diagnostic | Therapeutic | |
|---|---|---|
| Medication | Local anesthetic only — no steroid. | Local anesthetic plus corticosteroid. |
| Purpose | Temporarily numb the joint to test whether it is causing your usual pain. | Reduce SI-joint inflammation and provide longer-lasting relief. |
How will the result be evaluated?
- Diagnostic: record your pain before the injection and during the expected local-anesthetic window. Perform normal, safe activities that usually provoke your SI-joint pain and note the percentage and duration of relief.
- Therapeutic: track pain relief and improvements in walking, standing, sitting, sleep, exercise, and daily activities over the following days and weeks.
The exact relief threshold used to define a positive diagnostic injection depends on the clinical purpose and applicable coverage requirements.
Risks and possible side effects
Temporary soreness, bruising, numbness, leg heaviness, dizziness, fainting, or a pain flare may occur. Rare risks include infection, bleeding or hematoma, allergic reaction, unintended medication spread, nerve injury, or persistent worsening of pain. Serious complications are uncommon.
Preparing for Procedure Day
Medications
SI joint injections are generally low bleeding-risk procedures. NSAIDs and many prescribed blood thinners can often be continued, but patient-specific factors may change the plan. Never stop a prescribed medication on your own.
- Tell us if you take aspirin, Plavix/clopidogrel, warfarin, Eliquis/apixaban, Xarelto/rivaroxaban, Pradaxa/dabigatran, Lovenox/enoxaparin, or another blood thinner or antiplatelet medication.
- NSAIDs — including ibuprofen, naproxen, meloxicam, diclofenac, ketorolac, and celecoxib — are generally continued unless Renova Pain gives you different instructions.
GLP-1 medications for diabetes or weight loss
Examples include Ozempic®, Wegovy®, Mounjaro®, Zepbound®, Trulicity®, Victoza®, Saxenda®, Rybelsus® and similar drugs. Tell us the schedule, last dose, recent dose changes, and any nausea, vomiting, abdominal pain, bloating, or constipation. Follow the anesthesia team’s individualized instructions.
Tell us before the procedure
- Any infection, fever, antibiotics, open wound, recent hospitalization, pregnancy or possible pregnancy, contrast allergy, medication allergy, bleeding problem, new weakness or numbness, or major symptom change.
- Diabetes or poorly controlled blood sugar — steroid may temporarily raise glucose. Monitor as instructed and contact the clinician managing your diabetes for significant elevations.
Sedation and procedure-day checklist
Diagnostic injections are usually performed without sedation because sedation may affect pain reporting. If sedation is medically necessary or planned, follow the facility’s fasting and transportation instructions.
If instructed to fast: no solid food for at least 8 hours before arrival; stop clear liquids 2 hours before arrival unless the facility gives stricter instructions.
Take only approved morning medications with a small sip of water. Ask specifically about insulin and other diabetes medications.
Wear loose clothing. Bring a photo ID and updated medication list. If sedated, arrange for a responsible adult to drive you home.
What to Expect After an SI Injection
Diagnostic injection — local anesthetic only
- Relief may begin within minutes and should generally last only as long as the local anesthetic. Pain returning afterward does not mean the diagnostic injection failed.
- Complete the pain diary carefully. Record pain before the injection, immediately afterward, and at the requested time points while performing safe activities that usually cause pain.
Therapeutic injection — with corticosteroid
- The local anesthetic may provide brief relief. The steroid usually begins helping over 2–7 days; improvement may continue for up to 2 weeks and can last weeks to months.
- A temporary pain flare, facial flushing, insomnia, mood change, headache, menstrual change, or increased blood sugar may occur. Contact us if symptoms are severe or persistent.
Bandage, bathing, activity, and sedation safety
When to Call
Call us promptly if you develop fever, chills, increasing redness, warmth, swelling, drainage, severe or rapidly worsening pain, persistent numbness or weakness, difficulty walking, severe headache, uncontrolled blood sugar, or signs of an allergic reaction.
Call 911 or go to the nearest emergency department for new paralysis, loss of bowel or bladder control, trouble breathing, facial or throat swelling, chest pain, or loss of consciousness.
General education only. Follow the individualized instructions from your procedural team and call with questions.