Sacroiliac Joint Diagnostic Injections


An accurate diagnosis of sacroiliac joint dysfunction can be difficult. The symptoms mimic other common conditions, such as disc herniation and radiculopathy (pain along the sciatic nerve that radiates down the leg).

Sacroiliac (SI) joint presents pain frequently is difficult to distinguish from facet pain. The SI joint is large and bilateral, connecting the spine to the pelvis. Pain typically occurs with direct palpation, with thigh extension and/or with hip flexion and external rotation. The SI joint is frequently overlooked as a source of pain.

Diagnosis and therapy are accomplished by injecting the joint with local anesthetic and steroid. These injections are frequently performed without X-ray guidance, but there is little guarantee that a “blind” injection will result in joint infiltration and, therefore, such injections have limited diagnostic value. At SPS, SI joint injections are performed under fluoroscopic guidance, but even with the use of radiological guidance, the correct needle placement is frequently difficult.


The patient is placed supine and the fluoroscope is angled obliquely toward the caudal aspect of the joint. A 22 or 25 gauge needle is placed and 0.5 to 1 cc of contrast is injected. If placement is confirmed, one to two cc’s of local anesthetic and steroid is injected. Diagnosis of the SI joint’s involvement in the generation of pain is confirmed by the resolution of the patient’s pain, secondary to the local anesthetic effect. The injections may be repeated two-to-three times a year in order to obtain extended relief.

If the injection relieves the patient’s pain, it can be inferred that the sacroiliac joint is the source of the pain. Usually, a steroid solution is injected at the same time to decrease inflammation in the joint and decrease pain.

The following is the protocol at SPS:

  1. SPS contacts the patient 24-48 hours in advance to review medications/allergies
  2. Blood thinners are stopped 48 hours in advance.
  3. The patient will need a driver. Due to the effects of certain medications, the patient’s driving reflexes may be impaired. Consequently, he/she should arrange for a driver in advance


A small minority of patients