Pain in your lower back or buttocks that just won’t go away might not be from your spine—it could be your sacroiliac (SI) joint. This joint connects the sacrum at the base of your spine to your pelvic bones and plays a key role in stability and movement. When it becomes inflamed or unstable, it can cause serious pain and limit mobility.
In this blog, we’ll explore:
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Why SI joint pain happens
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The difference between inflammation vs. instability
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The most effective non-surgical treatments
How the SI Joint Works
The SI joint doesn’t move much, but it’s stabilized by a strong network of ligaments, muscles, and fascia. These structures absorb shock and keep your body aligned. Pain arises when ligaments are overstretched or when inflammation develops inside the joint.
Inflammatory SI Joint Pain
Sometimes, SI joint pain is caused by autoimmune inflammation. Conditions such as:
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Ankylosing spondylitis
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Psoriatic arthritis
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Inflammatory bowel disease-related arthritis
In these cases, the immune system attacks the joint, causing pain and stiffness.
Signs of inflammatory pain include:
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Pain worse in the morning or waking you early
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Stiffness lasting more than 60 minutes after waking
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Pain improving with movement but worse with rest
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Onset before age 40
Testing may show:
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MRI changes such as bone marrow edema or sacroiliitis
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Elevated CRP or SED rate
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Positive HLA-B27 antibody
If untreated, inflammation can fuse the joint and cause permanent damage. Biologic medications—including TNF inhibitors (Humira, Enbrel, Remicade) and IL-17 inhibitors (Cosentyx)—can reduce inflammation, relieve pain, and protect long-term joint health.
Mechanical SI Joint Pain
Most SI joint pain comes from mechanical instability, often related to:
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Osteoarthritis or wear-and-tear
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Repetitive motion injuries
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Trauma such as falls or car accidents
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Pregnancy-related ligament changes
Clues pointing to instability include:
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Pain worse with standing, walking, or climbing stairs
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Pain when rolling in bed or getting in/out of a car
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Tenderness directly over the SI joint
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Normal blood tests without inflammation
While X-rays and MRIs may not reveal ligament damage, functional testing, ultrasound, or diagnostic injections can confirm the problem.
Non-Surgical Treatment Options
Conservative Care
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Pelvic stabilization exercises
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Targeted physical therapy for SI joint support
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Strengthening of the core, glutes, and pelvic floor
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Postural retraining and safe movement strategies
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SI belts or bracing for temporary stability
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Nutrition and supplements: curcumin, omega-3s, glucosamine, and Boswellia
Regenerative Medicine
When instability or ligament damage is the cause, regenerative options can restore stability:
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Prolotherapy – sugar-based solution to strengthen ligaments
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Platelet-Rich Plasma (PRP) – concentrated platelets to promote healing
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Platelet Lysate – refined PRP for nerve-related pain
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Bone marrow aspirate concentrate (mesenchymal stem cells) – for advanced degeneration or chronic instability
These treatments are guided by ultrasound or fluoroscopy for precision and aim to fix the root cause, not just mask symptoms.
Treatments to Avoid
Some procedures may provide short-term relief but don’t address instability, such as:
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Steroid injections – may damage tissue with repeated use
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Radiofrequency ablation (RFA) – burns pain nerves but doesn’t fix instability
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SI joint fusion surgery – invasive and often unnecessary
Takeaway
SI joint pain is real, common, and treatable without surgery. Whether caused by inflammation or instability, the key is accurate diagnosis and personalized care. With conservative measures and regenerative treatments, most patients can restore stability, reduce pain, and return to living well.
How Ankylosing Spondylitis Differs in Men and Women
What Is Non-Radiographic Spondyloarthropathy? Understanding Back Pain with Normal Imaging
Ankylosing Spondylitis vs. Mechanical Back Pain: Key Differences & When to Seek Help