A comprehensive history and physical examination is the first step in this process. Understanding the location, nature, and pattern of your pain is critical in differentiating SI joint pain from other spinal problems, such as, herniated discs, degenerative disc disease, and lumbar stenosis, as well as hip problems. During your physical examination, care is taken check the spine and hip joints, and well as the SI joint through provocative maneuvers (thigh thrust, compression and distraction tests, FABER and Gaenslen positioning).
Imaging studies are needed to visualize the SI joint, and ensure that other problems in the lumbar spine and hip joints are not contributing to the problem. X-rays, CT scans, and MRI studies are often used.
The last component in diagnosis involves image-guided injections into the SI joint. Diagnostic injections typically include an arthogram (injection of dye into the joint) combined with local anesthetic to provide pain relief. If there is at least 50% reduction in pain, then the SI joint is the likely source of your pain. Occasionally steroids are injected into the joint for prolonged pain relief and therapeutic purposes.