Medial Branch Nerve Block

Diagnostic Medial Branch Nerve Block is the procedure that is used to determine whether one or more facet joints is the source of neck or low back pain. There is very poor correlation between the X-ray or CT appearance of the joint and whether it hurts. Joints that look bad may not hurt, and joints that look normal may be painful. The medial branches are the nerves that supply the facet joints. If we anesthetize the nerves to a specific joint, the pain that goes away was coming from the joint. If we prove that the joint is the source of the pain, we can perform a neurotomy, (heat the nerve) which may keep the pain under control for six to eighteen months. If the pain is not relieved by MBB, then the facet joint is not the cause of the pain (see Fig.1 below).