Each vertebra in the spine is connected to the vertebra above and below it by facet joints, which are located on the both sides of the rear of the spine. Facet joint block can be both diagnostic and therapeutic for back or neck pain. The facet joint block injection can confirm whether the facet joints are indeed the source of the pain and can help relieve the pain and inflammation. Small area of the skin is numbed with a local anesthetic injection. Guided by fluoroscopy x-ray, a needle is placed into the facet joint. The correct placement of the needle is confirmed by injecting contrast dye into the joint. A combination of a numbing anesthetic and an anti-inflammatory steroid medication is delivered to the joint through a thin needle. Depending on the location of the pain, one or more injections may be administered. If the pain subsides after the injection, this suggests that the facet joint (or joints) injected were the cause of pain. Back or neck pain may disappear immediately after a successful block. However, once the numbing effect of the anesthetic wears off, pain may return. It usually takes 5 to 10 days for the steroid medication to reduce inflammation and alleviate pain. Effects may last several days or several months. Up to 3 injections may be given per year.