Lumbar Medial Branch Block (Facet Nerve Injection)

Lumbar Medial Branch Block (Facet Nerve Injection)


A common source of low back pain, is arthritis of the facet joints. These are small synovial joints (like other joints in the body) that allow for movement of the low back. When arthritis becomes significant enough to involve these small joints, simple movements such as bending, twisting, standing, or walking can create significant pain in the low back. This pain is transmitted to the brain by a small nerve from each joint, called the Medial Branch Nerve. Blocking this nerve with local anesthetic medication may temporarily aleviate pain coming from these joints. This is a step in the process of identifying your pain, and identifying patients who may be eligible for radiofrequency ablation (neurolysis), which is a procedure that provide longer lasting relief, often 9-12 months duration.

Goal of the injection

In order to determine if pain in the low back is coming from arthritis of the facet joints, we use a diagnostic procedure called Medial Branch Diagnostic Blocks. The goal of this procedure is to place a small amount of local anesthetic on the Medial Branch Nerve, which sits over the joint. While the medial branch nerve is anesthetized, the pain transmitted from the low back should be significantly improved – helping us to localize the source of your low back pain.

The procedure

The patient is brought into a sterile procedure suite, and asked to lay face down on the exam table. Using X-ray guidance, the skin is anesthetized and a small needle is inserted over each area of interest. Once the needle is in proper location, over the medial branch nerve of each location, a small amount of anesthetic is injected. Following injection, the patient is cared for in the recovery area for a brief amount of time, and then discharged home.

After the procedure

Follow the specific instructions given to you by the nurses at the time of discharge from the recovery area:

  • Resume activity as tolerated
  • You are encouraged to perform activities that typically cause an increase in your normal pain. This is used to “test” whether the diagnosstic procedure is helpful in reducing your pain
  • Do NOT soak in a bathtub or lake for 24 hours after the procedure. You may shower.
  • Keep a record of your pain and symptoms in the immediate hours after your injection
  • You will receive a phone call from a clinic  nurse, asking about the relief of symptoms  you experienced after your injection. If  you meet specific criteria designated by the  insurance companies, you may be scheduled  for a second diagnostic block – or you may  be scheduled for radiofrequency ablation as  the next step.

If your procedure includes sedation

  • You should have no solid foods for 8 hours before the procedure.
  • You may have clear liquids up to 2 hours before your procedure. Examples of these clear liquids are:  water, broth, clear juices with NO pulp, tea, coffee WITHOUT cream. Carbonated beverages are NOT allowed.
  • No gum chewing for 2 hours before your procedure.
  • No candy, throat lozenges, or mints.
  • A nurse will call you before your procedure to review your medications and make recommendations as to what medicines you should take before your procedure.

Failure to comply with these instructions may result in cancellation and rescheduling of your procedure.

Potential risks of the procedure

Facet joint injections are considered safe, non-surgical, minimally invasive treatments. As with all medical procedures, there associated risks and side-effects that may vary between each patient. These rare but potential risks are:

  • Pain at the injection site
  • Infection in the form of an epidural abscess or at the skin. In very rare instances minor infections can occur
  • Stroke
  • Dural puncture or cerebral spinal fluid leak.  This typically presents as a headache that is worse with upright position and completely alleviated when lying flat
  • Increased pain or worsening symptoms.
  • Bleeding in the form of an epidural hematoma or at the site. You may suffer bleeding from undergoing procedures, especially while on blood thinning medications. Please notify us if you are taking any of the following blood
  • thinning medications:
  • Plavix (Clopidogrel), Aspirin, XareltoWarfarin (Coumadin), 
  • (Rivaroxaban), Heparin, Lovenox  (Enoxaparin), Brilinta (Ticagrelor), or any others not listed.
  • Nerve or spinal cord damage. In extremely rare instances, a patient may suffer nerve or spinal cord damage from direct trauma from a needle. This could potentially result in permanent nerve damage or paralysis.
  • Allergic reactions to medications. The commonly used medications in this procedure include: Lidocaine, Bupivacaine, Ropivacaine, and IV contrast dye.
  • Other risks are not limited to, but include:  epidural fibrosis, aseptic meningitis, GI side effects, renal failure, seroma, and paralysis.
  • Inability to complete the injection due to technical or anatomic difficulty.

Insurance requirements

Insurance companies have a series of requirements that must be met, prior to their approval of epidural steroid injections. These may vary between insurance companies, however; they commonly include:

  • Physical Therapy – often a minimum of 4 weeksin duration
  • Appropriate imaging, which may include X-raysor MRI.
  • Documentation of failure to improve with otherconservative medical therapies