Your doctor will perform a thorough history and physical examination, and ask questions to help determine whether the pain is coming from the SI joints, lumbar spine or hips. A neurosurgeon or pain medicine specialist can develop a probable diagnosis of SI joint dysfunction by palpating the painful areas and performing several movements that may cause pain:
The Gaenslen test applies torsion to the joint. With one hip flexed into the abdomen, the other leg is allowed to dangle off the edge of the table. Downward pressure on the leg causes hip extension and stresses the SI joint.
The iliac gapping test applies pressure to the anterior superior iliac spine.
The iliac compression test applies compression to the joint while you lie on your side.
The FABER or Patrick test helps determine if pain is coming from the SI joints during flexion, abduction and external rotation.
Diagnostic tests include x-rays, CT scan and MRI to evaluate the condition of the joints, bones, muscles and ligaments.
Your pain medicine specialist may inject an anesthetic and a steroid directly into the SI joint using fluoroscopy for either diagnosis or treatment.