Get the Right Diagnostic Test

To determine whether you have a sacroiliac (SI) joint dysfunction, it's very important that you get the right diagnostic tests. Here are the most commonly accepted methods to diagnose SI joint dysfunction.


SI Joint Pain Tests

Sacroiliac joint dysfunction tests include discussing your history and pain experience, a physical examination, tests to rule out other sources of pain, like lumbar spine pain and hip pain, and these commonly accepted methods:

  1. Provocative tests
  2. Diagnostic imaging (X-ray, CT, MRI)
  3. Diagnostic SI joint injections of the SI joint

Provocative SI Joint Tests

Your doctor may perform a series of provocative tests or exams to manipulate your joints or feel for tenderness over your SI joint. All of these can help establish a diagnosis.6,7,8,9,10 Provocative SI joint tests include:

  • Distraction
  • Thigh thrust
  • Compression
  • Gaenslen

In five different positions, your doctor will apply pressure to your hips, knees, and other areas to see which positions may cause discomfort or pain.

Provocative Test - Thigh Thrust (Diagnosis)

Diagnostic Imaging

In addition, X-rays, a CT scan, or MRI may be helpful in diagnosis. It is also important to remember that more than one condition (like a disc or hip problem) can co-exist with SI joint problems and your doctor should check for other factors that may be causing symptoms.

Provocative Tests

Diagnostic Injections of the SI Joint

The most widely used method to accurately determine the cause of SI joint pain is to inject the SI joint with local anesthetic.

Fluoroscopic guided SI joint injection with:

  • local anesthetic
  • contrast medium

Post-injection pain reduction:

  • ≥ 50% SI joint is likely the source of pain
  • < 50% Should consider other pain sources, but SI joint may be a component
Sacroiliac Joint Anatomy

During the SI joint injection procedure, a small amount of numbing medicine (a local anesthetic such as lidocaine) is injected into the SI joint under fluoroscopic guidance or CT guidance.

If the injection results in a significant decrease in SI joint pain (more than 50% pain relief) for an hour or two after the injection, then this is considered a positive or confirmatory diagnostic injection. This means your SI joint is most likely the cause of your pain.11

If the level of pain does not change after the injection, the SI joint is less likely to be the primary cause.

Get Answers

SI Joint Pain Quiz

Studies show that the SI joint is a source of pain in 15-30% of patients with chronic low back pain. Do you have SI joint pain? Take this short 7-step quiz to find out.

Take the Quiz

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