A sacroiliac joint injection involves introducing a local anesthetic and a steroid medication into the sacroiliac joint in the patient’s pelvis to treat pain. The purpose of a sacroiliac joint injection is two-fold: to diagnose the source of a patient’s pain, and provide therapeutic relief. At times, these are separated and a patient will undergo either a diagnostic or therapeutic injection, although often the two are combined into one injection. Due to the numbing agent used during this procedure, patients may experience temporary pain relief that may last several hours.