This type of spinal injection is commonly used to treat inflamed facet joints that cause back pain. The physician uses x-ray guidance called fluoroscopy to direct a special type of needle to the medial branch nerves that innervate the facet joints. Electrical current is passed through the needle to heat the medial branch nerve and create a lesion that disrupts the pain signal from the joint. This procedure is also called radiofrequency neurotomy or radiofrequency rhizotomy. It can treat pain that doesn’t respond to medications or to physical therapy.