Sacroiliac Joint Insufficiency
Question: What is sacroiliac (SI) joint dysfunction, and why can it be confused with a lumbar disc herniation?
Answer: The sacroiliac joint lies between the tailbone (sacrum) and the pelvic bone. Excess motion in the joint or SI-joint–origin pain can mimic lumbar disc herniation and sciatica-like symptoms. In clinical series, the SI joint may be the pain source in approximately 15–30% of patients with low back pain.
Question: Isn’t there a “special test” for diagnosis?
Answer: Diagnosis is typically suspected based on history and examination (provocation tests) and, when necessary, supported with methods such as diagnostic injections/blocks. Many studies have examined the diagnostic value of evaluating provocation tests together.
“Is it a disc herniation or the SI joint?” What should I look for at home?
Answer (practical observations):
- If pain is mainly on the side/back of the hip and lower back area, and there is no typical leg-line numbness/electric-shock sensation suggestive of a disc herniation, the SI joint may be considered.
- If pain is triggered from a single point (the junction of the lower back and hip), note it.
- For a definite distinction, an examination is needed rather than “home tests.”