Medial Branch Blocks

Medial Branch Blocks (MBB)

The spinal facet joints are a pair of joints on the posterior aspect of the spine. There is a right and a left facet joint located between each vertebral segment. These joints assist in movements and provide stability/support for the spine. Unfortunately, these small joints are often a source of pain for the back and neck.

The medial branch is the name of the nerve that supplies the facet joint. It is also the nerve that communicates pain signals to the brain. A medial branch block is an injection that aids in the diagnosis of facet arthritis. A Medial Branch Block places anesthetic (numbing) medication around these medial branch nerves to “block” any pain signals.

These injections are only a test. The goal of the injection is to determine how much pain relief is achieved from numbing the facet joints. If you feel significant improvement in your typical pain after a MBB, then we can be more confident that your pain is coming from these joints. Unfortunately, the numbing medication does not last long (pain will come back after several hours). However, if you have great benefit in the few hours after the MBB, then the definitive treatment for this pain is a radiofrequency ablation (RFA). See Radiofrequency Ablation .

Your physician will talk with you about your symptoms and perform a thorough physical examination to determine the source of your pain. Imaging, such as x-rays and MRI, can help to assist in this diagnosis, if needed. If you have arthritis in the neck, symptoms may include neck pain, shoulder pain and pain between the shoulder blades. This pain is usually worse with looking up and rotation of the head. If you have arthritis in the lower back, symptoms may include low back pain, buttocks pain and upper leg pain. Usually, low back arthritis is more painful with standing, walking, rolling over in bed, standing up from a seated position and arching your back. This pain tends to be less with sitting and bending forward. During your appointment in the office, your doctor will discuss the reasons he feels that your pain is related to spine arthritis.
There are a few recommended criteria to be considered a good candidate for an MBB. Usually, patients should have failed to improve with appropriate conservative measures, such as anti-inflammatory medications, physical therapy, chiropractic care, massage, etc. Prior to being considered a candidate for an injection, most patients will need some form of imaging (x-ray, MRI, etc.) to correlate with history and exam findings. Medial branch blocks tend to have the best results when the majority of pain is coming from the facet joints.
The procedure does involve placing a needle through the skin, so you may feel some mild discomfort. Local anesthetic is used to numb the skin and lessen the pain associated with skin puncture. If you wish, mild IV sedation and pain medication may be given prior to the injection to make you as comfortable as possible (discuss with your doctor). During the injection, it is possible to feel some pain in the back or neck when the needle tip touches the bones of the facet joint. This is quite common. The physician will be as gentle as possible around these painful areas to make sure the injection is as pain free as possible. Most patients tolerate this procedure without significant discomfort.
The medication used during a MBB is an anesthetic medication. The relief from this injection can start to occur about 5-20 minutes after the injection.
Medial branch blocks can provide great pain relief for facet joint arthritis, but provide minimal or no relief for other spine conditions. If most of your pain is coming from the facet joints in the back or neck, there is a good chance that the MBBs will help a significant portion of your pain. If you have other conditions, such as degenerative disc disease contributing to your pain, then the MBB may only provide relief for a portion of your pain. Most patients receiving medial branch blocks do not experience 100% pain relief, since they often have more sources of pain than just spine arthritis. The goal of the MBB is to show a significant reduction (greater than 80% improvement) in pain during the testing period immediately following the injection.
This nerve block is only a test; the pain relieving effects are only TEMPORARY. The effects of the numbing medication will wear off over the duration of several hours. It is expected that your typical pain will return after the numbing medication wears off. If you are truly getting pain from the facet joints, the numbing medicine should provide substantial pain relief for those several hours. Return of pain after the injection does not signify a failed injection, as this is EXPECTED. If you get good pain relief for a few hours after the MBB, then the definitive treatment for this condition is called radiofrequency ablation (RFA). See radiofrequency ablation for more details on this procedure.

If you had a significant response to your first MBB, then the follow up injection can be either a second MBB or RFA. This will often depend on your insurance. Some insurance carriers require that we perform medial branch blocks twice prior to proceeding with radiofrequency ablation. Some insurance companies require only one medial branch block prior to proceeding with radiofrequency ablation. We will check with your insurance company to determine how many injections you will need. If you did not have a benefit from the first MBB, then your doctor will re-evaluate your condition to determine the next step in the treatment plan.

If you have a great response to the first FJI (>80% pain reduction), then there is no need to have a second injection immediately. FJIs can always be repeated in the future if the same pain should return.

If you have had 80% improvement, but 20% improvement in your pain following your first FJI, a second injection may provide some “additive” benefit. A subset of patients require two injections to see benefits of the injection. You can discuss the possibility of a second injection at your 2 week follow up visit.

If you had minimal improvement with FJI (20% pain reduction), then your doctor will re-evaluate your condition to determine the next step in the treatment plan.

Due to the side effects of steroids, it is recommended that you get no more than 4 FJIs per calendar year. At most, three injections can be performed in a 6 month period.

A medial branch block that does not help the pain provides very valuable information for your physician. If numbing the nerves to the facet joints does not produce significant relief of pain, then the facet joints are not likely to be a major source of your pain. The physician can then focus on other possible causes of pain for you.

Will I eventually need surgery for my spine condition? The goal of our clinic is to prevent surgical intervention, if possible. There are a few reasons to have surgery on your neck or back. These reasons are:

Progressing/Worsening weakness

Sudden numbness in the genital area (saddle anesthesia)

Sudden loss of bowel and/or bladder control.

Severe pain that you cannot tolerate and pain that is not helped with conservative treatments (medications, physical therapy, chiropractic care, injections, etc.)

If you should ever develop any sudden weakness, saddle anesthesia or loss of bowel/bladder control, you should call your doctor immediately. If you cannot reach your doctor, you need to go to the emergency room immediately to get evaluated.

No, for your safety. You have the option to have mild sedation through an IV prior to the procedure, however, you cannot be put under general anesthesia for this injection. Your feedback is critical to the safety of the MBB. As the needle approaches the target, it is possible that the needle will come close to the spinal nerves. If this should happen, you may feel some discomfort traveling down your arm or leg. We rely on you to tell us this information, so that we can adjust the needle to another location. If you are put under general anesthesia, there is an increased risk of nerve damage from the needle.

The other reason that you should not have general anesthesia for this procedure is because it is a diagnostic injection. We want all pain relief from the injection to be related to the numbing medication placed around the nerves, not due to the general anesthetic. For this same reason, we ask that you do not take any pain medication prior to your procedure.

Medial Branch Blocks are not performed in our office. They are performed in an ambulatory surgery center with the use of fluoroscopic (live x-ray) guidance. X-ray guidance is critical to ensure that the injection is placed in the correct location. You will usually arrive at the surgery center about 20-30 minutes prior to your appointment to get set up for the procedure. If you are going to get IV sedation with your injection, you will be asked to not eat food for 4-6 hours prior to your procedure or drink any liquids for 2 hours prior to your procedure. The decision to get sedation or pain medication is always optional. The total duration of the procedure usually takes about 10-15 minutes. Your doctor will discuss this procedure more in detail during your office visit prior to the injection. If you want IV medication prior to the procedure, you will be required to have a responsible adult driver to get you home. If you do not have a driver, then we unfortunately cannot give you any IV medication.

Prior to getting on the procedure table, you will be tested by the physician to see how much pain you are having on that day. Prior to leaving the surgery center, the physician will test you again to see if your pain has changed. You will be given a homework sheet (pain diary), which will require you to fill out your pain levels for the first 8 hours after the procedure. Typically, you will be seen in the office in the first couple days after the procedure to see how well you responded to the injection and to discuss future treatment options.

Generally speaking, this procedure is very safe. However, as with any procedure, there are risks, side effects, and the possibility of complications. Some of these common risks are listed below.

Pain:The injection site may be sore after the injection, due to the needle passing through painful tissue. Usually, any increase in pain is temporary. In most cases, very little discomfort is felt by the patient.

Bruising at the site of injection

Infection:Rare. The skin is cleaned thoroughly prior to the injection to minimize this risk. Everything is done under sterile technique.

Bleeding:Usually any bleeding stops spontaneously. To minimize any bleeding risk, we ask that you stop all blood thinning medications prior to the procedure.

Nerve Damage, Seizures, Paralysis, Death:Exceedingly rare complications.


Pre-Procedure Instructions:

  • Stop all aspirin based products and non-steroidial anti-inflammatory (NSAIDs) medications for 5 days prior to your injection. Examples of NSAIDs include Ibuprofen (Advil, Motrin), Naproxyn (Aleve, Naprosyn, Anaprox), Indocin (Indomethacin), Lodine (Etodolac), Relafen (Nabumetone), Daypro (Oxaprozin), Meloxicam (Mobic), Diclofenac (Voltaren, Arthrotec), etc. Celebrex, although a NSAID, does not need to be stopped. If you have any question if a medication you are taking needs to be stopped, please ask your doctor.
  • Stop fish oil and Vitamin E supplements for 5 days prior to your injection.
  • Stop all blood thinning medication, including warfarin (Coumadin), pradaxa, debigatran, argatroban, plavix, etc. for 5-7 days prior to the injection. You may need to get permission from your prescribing doctor prior to getting off of these medications prior your injection to ensure that it is safe to stop these medications.
  • DO NOT TAKE pain medication on the morning of this procedure. We want the only pain relief that you experience to be the result of this injection.
  • You should take all of your other medications, such as your blood pressure medications, with a small amount of water prior to your injection.
  • Do not eat for 4-6 hours prior to your injection.
  • Do not drink for 2 hours prior to your injection.
  • You may be required to have lab work or an EKG prior to your procedure. Discuss this with your pain physician.
  • For your safety, you should have a responsible adult to drive you home after your injection. If you cannot get a driver to bring you home, you must tell your treating physician. If you do not have a driver, then you will not be able to have IV sedation. Failure to have a driver may result in the cancellation of your procedure.
  • Post-injection Instructions:

  • Following your injection, you should perform the normal activities that cause your pain. The goal during this day will be to see if your pain improves because of the numbing medication. You will be asked to fill out a pain log to keep track of your pain scores for the first 6-8 hours after the injection. Do not go to sleep during this testing period time.
  • You should avoid all pain medications for the first 6-8 hours after your injection, as this is the testing period to see if the numbing medication helps the pain.
  • You may resume all aspirin, NSAIDs and blood thinning medications the night of your injection or the following morning. Wait at least 6 hours after your injection before resuming NSAIDs.
  • Recommend that you avoid icing the back for the first 6 hours after the injection. After the testing period ends, you may use ice compresses over the injection site – 20 minutes on, then 20 minutes off. Repeat this cycle as required. If using a gel pack, make sure a towel or piece of cloth is placed between the cold pack and the skin. Do not apply the cold packs to the numb areas following injection.
  • You may eat and drink after your injection is completed.
  • You may shower immediately, but please avoid swimming or baths/Jacuzzis/hot tubs for the first 2 days after the procedure, to reduce the risk of infection.
  • Should you develop fever, chills, drainage, excessive swelling or redness at the injection site, bladder or bowel dysfunction, or change in sensation or muscle strength, please contact our office immediately. If you cannot reach your physician, please present to the nearest emergency room.
  • If you experience a post-procedure headache, please contact our office. For the first 24 hours, lie down as much as possible. You can take Tylenol up to 3 grams per day in doses of 1 gram every 8 hours. Drink plenty of fluids in the form of caffeinated beverages. The caffeine will often minimize the headache substantially. If you continue with headaches after 24 hours following the procedure, please contact our office.
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