Determining the source of your symptoms
The most important information you can give your doctor is the exact location of your pain and level of your functionality. Try to notice when the pain occurs and how intensely you feel it in various locations, including your lower back, buttocks, and legs.
Also, be sure to tell your doctor about any previous injury that may have either directly affected your pelvis, or caused you to walk asymmetrically, or may relate in any way to your functionality.
Your doctor will consider all the information you provide, including any history of injury, location of your pain, and problems standing or sleeping. A variety of diagnostic tests may help determine whether the SI joint is a source of your symptoms.
SI Joint Exam
Your doctor may perform a series of provocative tests to manipulate your joints or feel for tenderness over your SI joint. All of these can help establish a diagnosis.1
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 will need to check for other factors that may be causing your symptoms.
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 pain medicine.
Your doctor will deliver the injection with either fluoroscopic guidance or CT guidance to ensure that the needle is accurately placed in the sacroiliac joint. If, following the injection, your pain is decreased a significant amount, then it can be concluded that the SI joint is either the source, or a major contributor, to your lower back pain.2 If the level of pain does not change after the injection, the SI joint is less likely to be the primary cause.