Lumbar Medial Branch Block

Purpose – To determine if the zygapophyseal (facet) joints are the source of pain. This is a temporary test; however, if the facet joints are the cause of pain, a long-term procedure, such as radiofrequency ablation, may be performed.
Overview – The injection delivers a dose of anesthetic directly to the lumbar medial branch nerves in order to establish a diagnosis. These nerves do not control any muscles, or sensation of the arms or legs, but are small nerve branches that communicate pain caused by the facet joints in the spine.
Before the procedure – Make sure you have a driver to bring you to and from your appointment. Beware that occasionally people will have a reaction to the contrast that is injected.
Details – X-ray images are taken, then numbing solution is injected in multiple areas to anesthetize the skin. In each location radiopaque dye is used as a contrast solution under x-ray guidance to confirm the correct needle position. Once the accurate location is determined, the anesthetic is injected in the lumbar medial branch nerves.
After the procedure – It is best to continue with normal activity in order to assess the accuracy of the test and confirm the location of the nerve irritation or entrapment. In a couple of days the office will call you to assess effectiveness, or you will have a follow up visit.
Potential Complications – Allergic reaction to medication, nerve damage, or bruising of the injection site.