If you’ve tried everything for your lower back pain and nothing seems to work, your sacroiliac (SI) joint might be the overlooked culprit. SI joint dysfunction accounts for up to 15–30% of chronic low back pain cases, but is often misdiagnosed【Forst et al., 2006†source】.

What Is the SI Joint?

The SI joints sit where your spine meets your pelvis, acting as small shock absorbers. When they move too much (instability) or too little (stiffness), pain can radiate into your lower back, buttocks, or hips — sometimes mimicking sciatica【Dreyfuss et al., 2004†source】.

Causes and Symptoms

Common causes include prior lumbar fusion surgery, pregnancy, trauma, arthritis, or gait changes. Pain typically worsens when standing, walking, or climbing stairs. A physical exam plus a diagnostic injection can confirm if the SI joint is the pain source.

Treatment Options

Most patients start with conservative treatments — physical therapy, anti-inflammatories, SI belts, or injections. When pain persists, fusion surgery may be recommended to stabilize the joint and stop painful motion【Chin et al., 2025†source】.

Modern Fusion Approaches

Traditional SI fusions often required open surgery and lengthy recovery. Newer percutaneous techniques — like the Sacrix™ SI Fusion System — use a lateral-oblique approach with variable-threaded screws, preserving soft tissue and allowing same-day surgery. This aligns with the LESS™ Society’s R.E.P. philosophy: Restore function, Enable early mobility, Preserve anatomy【Chin et al., 2023†source】.

Takeaway

If you have persistent low back or buttock pain, ask your doctor about an SI joint evaluation. Modern LESS-aligned fusion options offer faster recovery, less tissue disruption, and better long-term outcomes.