Accurate diagnosis of sacroiliac joint dysfunction Accurately diagnosing 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). A diagnosis is usually arrived at through physical examination and/or an injection: Physical examination to determine the source of pain In physical examination, the doctor may try to determine if the sacroiliac joint is the cause of pain through movement of the joint. If the movement recreates the patient’s pain, and no other cause of pain has been found (such as a disc herniation on an MRI scan), the sacroiliac joint may be the cause of the pain. There are several orthopedic provocative tests that can be used in attempt to reproduce the symptoms associated with sacroiliac joint dysfunction. As a rule, several positive tests that reproduce pain specifically located at the sacroiliac joint improves the probability of the diagnosis of sacroiliac joint dysfunction. For example: The patient may lie face up on an examination table with the leg of the affected side resting on a nearby stool so that the sacroiliac joint lies on the edge of the table. In this position, there is no support for the hip joint and pressing down on the iliac crest (pelvis) may reproduce the patient’s pain. Injections to determine the source of pain A sacroiliac joint injection – sometimes called an arthrogram or sacroiliac joint block – can be a useful diagnostic test. It takes a highly skilled and experienced physician to be able to insert a needle into the correct portion of the sacroiliac joint. In this test, a physician uses fluoroscopic guidance (live X-ray) and inserts a needle into the sacroiliac joint to inject lidocaine (a numbing solution). 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 sacroiliac joint and decrease pain.