If facet joints of the spine are a suspected source of pain, a diagnostic or “test” injection is performed to determine/diagnose if the facet joints in the spine are a significant reason for your pain. This is called a medial branch block, an injection where the medial branches are numbed to “block” the nerve transmission from the targeted facet joint(s). This test only provides temporary information, if the facet joints are a significant source of your pain or not. If the medial branch block provides significant, yet transient relief, you may be a candidate for a procedure that may provide long term relief of facet joint pain. Radiofrequency neurotomy treatment is indicated for patients who receive at least a 50% reduction of the pain in question- typically for a couple of hours.