How will my doctor determine whether I have SI joint problems?
Your doctor will consider all the information you provide, including any history of injury, location of your pain, and problems standing or sleeping. Your doctor will also perform a physical examination. You may be asked to stand or move in different directions and point to where you feel pain. Your doctor may feel for tenderness over your SI joint.
In addition, X-rays, a CT scan, or MRI may or may not be helpful in the diagnosis of SI joint disorders. 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 pain.
The most widely used method to determine the cause of SI joint pain is to have a properly performed diagnostic SI joint injection with a local anesthetic. The injection will be delivered with either X-ray guidance or CT guidance to ensure that the needle is accurately placed in the SI joint. If, following the injection, your pain is decreased by more than 50%, then it is likely that the SI joint is either the source, or a major contributor to your lower back pain. If the level of pain does not change after the injection, it is unlikely that the SI joint is the cause of your lower back pain.