Understanding Sacroiliac Joint Dysfunction
The sacroiliac (SI) joints connect the sacrum — the triangular bone at the base of the spine — to the iliac bones of the pelvis. There are two SI joints, one on each side, and they transfer load between the upper body and legs. Although they have limited range of motion, they are subject to significant stress and can become a source of chronic pain.
SI joint dysfunction is estimated to account for 15–30% of chronic low back pain cases — yet it is frequently misdiagnosed as lumbar disc disease or hip arthritis. The key to diagnosis is targeted diagnostic injection, which both confirms the diagnosis and provides temporary relief.
- Deep buttock pain, often one-sided
- Pain that radiates into the hip, groin, or upper thigh
- Difficulty sitting for prolonged periods
- Pain rolling over in bed or climbing stairs
- Pain worse with standing on one leg
- Low back pain below the belt line
- Stiffness in the pelvis or sacral region
- Degenerative joint disease of the SI joint
- Pregnancy and post-partum ligamentous laxity
- Prior lumbar fusion (adjacent segment stress)
- Leg length discrepancy
- Inflammatory arthritis (ankylosing spondylitis)
- Traumatic injury to the pelvis
- Prolonged asymmetric loading or gait abnormalities
Treatment Pathway
Most spine conditions are managed with a stepped approach — starting with the least invasive option and progressing only when needed. Our surgeons evaluate each patient individually.
When Surgery May Help
SI joint fusion is considered for patients with confirmed SI joint-mediated pain — confirmed by diagnostic injection — who have not achieved adequate relief with at least 6 months of conservative management. The minimally invasive lateral approach uses small implants placed through a small incision with fluoroscopic guidance, and most patients return to walking the same day. Clinical evidence supports significant and durable reduction in pain and disability scores following minimally invasive SI joint fusion in well-selected patients.