Sacroiliac Joint Diagnosis:
Intra-articular Sacroiliac Joint Injection
The current reference standard for diagnosing sacroiliac joint pain is an image-guided, contrast-enhanced intra-articular injection with local anesthetic.
A double block technique, using a different local anesthetic for the second block, is recommended to rule out false-positive responses. Levels of pain relief used to determine positive response have been reported between 50%-90%,12,13 though the common clinical practice is to use ≥75% pain relief post-injection on VAS as the metric for defining a positive response.
The injection approach is usually posterior-inferior, with the distal one-third of the joint being the target site. The sacroiliac joint is very low volume, often holding only about 2 ml of fluid. Given this limitation, only about 0.25 ml of contrast followed by 1.25 ml of local anesthetic is typically utilized.
The following guidelines from the American Society of Interventional Pain Physicians (ASIPP) were published in 2009:14
Controlled sacroiliac joint blocks with placebo or controlled comparative local anesthetic blocks are recommended when indications are satisfied. A positive response is considered ≥80% relief with ability to perform previously painful movements.
- The primary indication for sacroiliac joint blocks is the need to know if a patient’s pain is arising from the sacroiliac joint or not.
- Sacroiliac joint injections are indicated in patients:
- With chronic low back pain that is maximal below the level of L5 vertebra
- With or without somatic referred pain in the lower limb, in whom no other diagnosis is readily apparent
- No other possible diagnosis is more likely
- A diagnosis has been made or cannot be made using less invasive options
- Lack of resolution of pain with the passage of time or conservative therapy.
The American Academy of Pain Management & Rehabilitation (AAPM&R) has published detailed educational guidelines on interventional spinal procedures.15 To view the guidelines for sacroiliac joint injection, click on the link to download the PDF.
Next page: Sacroiliac Joint Treatment Options
Sacroiliac Joint Pain Diagnosis
Sacroiliac Joint Treatment Options