Sacroiliac Joint (SIJ) Dysfunction

Sacroiliac (SIJ) joint dysfunction is a recognized but often underdiagnosed cause of low back, gluteal, and sometimes posterior hip or even leg pain. It accounts for an estimated 10–38% of cases of chronic low back pain. The SI joint’s complex anatomy and overlapping symptomatology with lumbar spine and hip pathology can make diagnosis challenging.

Etiology and Pathophysiology:
SI joint dysfunction can be mechanical (e.g., abnormal movement or instability), degenerative, inflammatory (such as in spondyloarthropathies), infectious, traumatic, or, rarely, neoplastic. Mechanical dysfunction is most common and is typically non-inflammatory.

Clinical Presentation:
Patients often report pain localized to the posterior superior iliac spine, buttock, or lower lumbar region, sometimes radiating to the groin or posterior thigh. Pain is usually unilateral, worsened by prolonged standing, walking, or transitional movements (e.g., standing from sitting). Some describe sciatica-like symptoms, but true radiculopathy is uncommon.

Diagnosis:

• History and Physical Exam:
  Diagnosis is primarily clinical. Provocative maneuvers (e.g., FABER, Gaenslen, thigh thrust, compression/distraction tests) are used, but no single test is highly sensitive or specific. The likelihood of SIJ involvement increases if three or more provocative tests are positive.
• Imaging:
  Imaging (X-ray, CT, MRI) is mainly used to exclude other causes or identify red flags (e.g., infection, fracture, tumor). Imaging findings for SIJ dysfunction are often non-specific.
• Diagnostic Injections:
  Image-guided intra-articular anesthetic injections can help confirm the SIJ as the pain generator, but false positives and negatives are possible.

Management:

• Conservative (First-line):
  • Physical therapy focusing on core and pelvic stabilization
  • NSAIDs or other analgesics
  • Manual therapy and exercise
  • Cognitive-behavioral therapy and, if needed, psychological support
• Interventional:
  • Image-guided corticosteroid injections (can provide relief for weeks to months)
  • Radiofrequency ablation (RFA) of the lateral branches of S1–S3 and L5 dorsal ramus; cooled RFA has shown the strongest evidence for efficacy
• Surgical:
  • Minimally invasive SIJ fusion is reserved for refractory cases after failure of conservative and interventional therapies. Evidence suggests improved outcomes compared to non-surgical management in selected patients.

Special Considerations:

• SIJ pain is more common after lumbar fusion, especially when the fusion extends to the sacrum or pelvis.
• Multidisciplinary and multimodal approaches are recommended, as outcomes are best when physical, pharmacologic, and interventional strategies are combined.

Overall, SIJ dysfunction should be considered in patients with persistent low back or buttock pain, especially when lumbar and hip pathology have been excluded.

Author

Paddy Kalish OD, JD and B.Arch Author and Blogger