Sacroiliac (SI) joint pain is one of the most common—and commonly overlooked—sources of lower back and pelvic pain. Because its symptoms often overlap with sciatica, hip pain, or lumbar spine issues, many people struggle for months or years before finding the right diagnosis. The good news? SI joint dysfunction is highly treatable once identified.
This post breaks down what causes SI joint pain, how it feels, and the most effective treatment options available today.
What Is the Sacroiliac Joint?
The sacroiliac joints connect your spine (the sacrum) to your pelvis (the ilium). You have one on each side, and they act like shock absorbers that stabilize your body during movement.
When these joints become irritated, inflamed, or too mobile—or not mobile enough—pain can develop across the low back, buttocks, or even down the leg.
Common Causes of SI Joint Pain
- Pregnancy and childbirth (ligament laxity + postural changes)
- Trauma, such as falls or car accidents
- Repetitive stress, including long walks, running, or prolonged sitting
- Arthritis or degeneration
- Leg length discrepancies
- Previous spine surgery, especially fusions
Because the SI joint is central to almost all lower-body movement, even subtle problems can cause significant discomfort.
Symptoms of Sacroiliac Joint Pain
- Pain on one side of the lower back or buttock
- Pain that worsens with standing up, climbing stairs, or turning in bed
- A feeling of instability or “catching” in the pelvis
- Pain that radiates into the groin or thigh
- Relief when lying down
SI joint pain is rarely symmetrical—most cases involve just one side.
How SI Joint Pain Is Diagnosed
Diagnosing SI joint dysfunction requires a combination of:
- Physical exam maneuvers designed to stress the SI joint
- Imaging (X-ray, MRI, CT), mostly to rule out other causes
- Diagnostic injections, the gold standard to confirm joint involvement
If pain relief occurs after the injection, the SI joint is confirmed as the source.
Effective Treatment Options
1. Conservative Care
- Physical therapy focused on pelvic stabilization
- SI belts or bracing
- Activity modification
- Anti-inflammatory strategies
2. SI Joint Injections
Corticosteroid or regenerative injections can reduce inflammation and pain while improving mobility. These are performed under imaging guidance for accuracy.
3. Radiofrequency Ablation (RFA)
If the surrounding nerves are consistently generating pain, RFA uses heat to interrupt pain signals. Relief often lasts several months or longer.
4. Regenerative Medicine
For ligament laxity or chronic instability, platelet-rich plasma (PRP) and other orthobiologic therapies may help strengthen supporting tissues around the joint.
5. Minimally Invasive SI Joint Fusion
For cases unresponsive to conservative or interventional treatments, SI joint fusion surgically stabilizes the joint. This minimally invasive procedure is typically reserved for severe or persistent dysfunction.
The Bottom Line
Sacroiliac joint pain is common—but often misdiagnosed. With better understanding, accurate diagnostics, and modern treatment options, most patients can achieve lasting relief and improved mobility.
If you’re dealing with persistent lower back or pelvic pain, evaluating the SI joint is a key step toward finding the right solution.
