What is sacroiliac joint dysfunction?
The sacroiliac joints - one on each side - connect the base of your spine (the sacrum) to your pelvis. They are strong, low-movement joints that transfer the weight of your upper body into your legs and absorb shock as you walk. Sacroiliac joint dysfunction (also called SI joint pain, SI joint dysfunction, or sacroiliac joint syndrome) is pain that arises when one of these joints moves too much or too little, or becomes inflamed.
It is a recognized source of low back pain. The pain is usually felt low down and to one side, in the back, buttock, or hip, and it can sometimes be mistaken for sciatica or a disc problem.
The reassuring part: SI joint pain is a mechanical problem, and most people improve with non-surgical care. Because it can mimic other conditions, our first job is to confirm the SI joint is actually the source before recommending any treatment.
Symptoms to look for
SI joint pain often has a recognizable pattern:
- Low back or buttock pain, usually on one side - sometimes described as deep or aching.
- Pain standing up from sitting, climbing stairs, or rolling over in bed.
- Pain that spreads into the hip, groin, or back of the thigh, and can feel sciatica-like.
- Stiffness or reduced movement in the lower back, pelvis, and hips.
- A sense of instability - the pelvis may feel as though it could give way.
Symptoms can flare and settle, and often worsen with prolonged standing, sitting, or one-sided activities. A careful examination - not the scan alone - is what tells us whether the SI joint is the real source.
NOTE
SI joint pain is not usually an emergency. But if low back pain follows a significant fall or accident, or comes with fever, unexplained weight loss, or new numbness, weakness, or loss of bladder or bowel control, see a doctor promptly so other causes can be ruled out.
What causes sacroiliac joint dysfunction?
SI joint pain can come from the joint moving too much (too little stability) or too little (stiffness), as well as from inflammation of the joint itself. Common contributors include pregnancy and childbirth, which loosen the pelvic ligaments; an injury such as a fall, a heavy landing, or a car accident; and arthritis or general wear with age. A difference in leg length, an altered walking pattern, or previous lower spine fusion surgery can change how load passes through the joint and add to the strain. Long hours seated and one-sided activities can also play a part, and inflammatory conditions such as ankylosing spondylitis can affect the joint too.
How we diagnose it
Diagnosis begins with your history and a focused examination, including gentle movement tests that stress the SI joint to reproduce your pain. Because the SI joint can mimic disc or hip problems, imaging such as X-ray, MRI, or CT is often used mainly to rule out other causes rather than to confirm the joint itself.
Where the source is unclear, a diagnostic SI joint injection - placing a small amount of local anesthetic into the joint under image guidance - can help confirm whether it is driving your pain. We match the findings to your symptoms and treat the person, not the scan. Your assessment is led by a US board-certified neurosurgeon.
Treatment - least invasive first
We follow a measured, surgery-last approach, starting with the simplest options that can give lasting relief.
- Conservative care (first line for most). Activity adjustments, short-term anti-inflammatory medication, and sometimes a pelvic support belt can settle a flare and ease day-to-day pain.
- Physiotherapy. A guided program of stretching and targeted strengthening for the muscles that support the pelvis and lower back, helping to stabilize the joint and improve how you move.
- SI joint injections. If pain persists, an image-guided injection can reduce inflammation in the joint, both easing symptoms and helping confirm the diagnosis.
Surgery for the SI joint is uncommon and is reserved for the small number of people whose pain does not respond to thorough non-surgical care. If you have already been told you need surgery, we are glad to give an honest second opinion on whether a less invasive path could work for you.
What to expect
Many people with SI joint pain improve over several weeks to a few months with activity changes and physiotherapy, though the exact timeline varies from person to person. Because it is often a mechanical problem, the focus is on stabilizing the joint and managing flares rather than a single quick fix. If you have an injection, relief can last from weeks to months and can usually be repeated if helpful. Your specialist will explain the likely timeline for your specific case, and the plan is built around you, with clear explanations at every step.
Common questions
What does sacroiliac joint pain feel like?
SI joint pain is usually felt low down and to one side of the back, in the buttock or hip, often as a deep ache. It can spread into the groin or the back of the thigh and feel like sciatica. It commonly worsens when you stand up from sitting, climb stairs, or roll over in bed.
What causes SI joint dysfunction to flare up?
Flares are often triggered by the joint moving too much or too little - after pregnancy, an injury or fall, or with arthritis and age. Prolonged sitting or standing, one-sided activities, a leg-length difference, or previous lower spine fusion can add strain. Identifying your triggers is part of settling the pain and preventing further flares.
How is sacroiliac joint dysfunction diagnosed?
Diagnosis starts with your history and a focused examination, including gentle movement tests that stress the joint to reproduce your pain. Scans are often used mainly to rule out other causes. Because the SI joint can mimic disc or hip problems, a diagnostic injection of local anesthetic into the joint can help confirm it is the source.
Can SI joint dysfunction be treated without surgery?
Usually, yes. Most SI joint pain improves with non-surgical care - activity changes, physiotherapy to stabilize the pelvis, short-term anti-inflammatory medication, and sometimes an image-guided injection. Surgery is uncommon and is reserved for the small number of people whose pain does not respond to thorough non-surgical treatment.
Is walking good for sacroiliac joint pain?
Gentle movement, including short walks, is generally helpful, as staying still for long periods can stiffen the joint and worsen pain. Very long walks or one-sided, high-impact activity may aggravate a flare. A physiotherapist can guide how much activity suits you and add targeted exercises to support the pelvis and lower back.
How long does SI joint dysfunction take to heal?
Many people improve over several weeks to a few months with activity changes and physiotherapy, though timelines vary from person to person. Because it is often a mechanical problem, the aim is to stabilize the joint and manage flares. If an injection is used, relief can last from weeks to months and can usually be repeated if it helps.