The sacroiliac joints connect the pelvic bones and spine. They are small and don’t move much. They absorb the force of the upper body before transferring the weight to the hips and legs. When one or both of these joints become irritated or injured, they can cause chronic discomfort and pain. SI joint injections can pinpoint and alleviate this pain. Guided by fluoroscopy (x-ray imaging), a pain specialist injects a local anesthetic into the affected SI joint. If the anesthetic relieves the patient’s pain, the diagnosis is confirmed. Corticosteroid medication, a robust and long-acting medicine reduces inflammation and provides pain relief over an extended period, is also injected. Immediate but temporary pain relief (lasting a few hours) may occur from the local anesthetic. The benefit from the corticosteroid will typically occur within two to four days following the procedure and may last for several months. A sacroiliac (SI) joint injection is helpful in treating low back and inflammation.