Medial Branch Blocks

Indications

Some doctors prefer to perform medial branch nerve blocks instead of facet joint injections. They are also used when the joints cannot be entered for anatomical reasons.

Technique

• As for intra-articular injections. In the Lumbar Spine  the nerves are blocked as they pass over the upper corner of the transverse process of the vertebra.
• In the Cervical Spine  they are blocked as they pass over the mid point of the waist of each vertebra.
• Usually 1.5  ml of local anesthetic is injected next to the nerve at each level. As each joint has a twin nerve supply from two spinal levels, so that two nerves have to be blocked to cover a single joint.

Problems

The local anesthetic lasts only a few hours, so patients have only a short time to find out whether the blocks have been successful before the local anesthetic wears off. A decision is then made about further treatment.

Aftercare

Local soreness can occur as for intra-articular injections.

Frequently Asked Questions

What is a Medial Branch?
Facet Joints are innervated or “supplied” by nerves called “medial branches”.  These nerves carry the pain signals to the spinal cord and the signals eventually reach the brain, where the pain is noticed.
 
What is the purpose of it?
If the nerves are “blocked” or “numbed”, they will not be able to carry pain sensation to the spinal cord.  It is like temporarily cutting off “wires”.  Therefore, if the pain is due to facet joint arthritis, you should have relief from pain and stiffness. Once it is determined that the pain is indeed due to facet joint disease, we can use a procedure called “Radio-Frequency Lesioning” and prevent the conduction of pain information for several weeks to months.
So, in a way, medial branch block is a temporary and diagnostic procedure.
 
How long does the injection take?
The actual injection takes only a few minutes.  More nerves to be blocked, more time it takes.
 
What is actually injected?
The injection consists of a of local anesthetic (like lidocaine or bupivacaine).
 
Will the injection hurt?
The procedure involves inserting a needle through skin and deeper tissues (like a “tetanus shot”).  Therefore, there is some discomfort involved.  However, we numb the skin and deeper tissues with a local anesthetic using a very thin needle before inserting the needle into the joint.  Most patients also receive intravenous sedation and analgesia, which makes the procedure easy to tolerate.
 
Will I be “put out” for this procedure?
No.  This procedure is done under local anesthesia.  Most patients also receive intravenous sedation and analgesia, which makes the procedure easier to tolerate.  The amount of sedation given generally depends upon the patient’s tolerance.
 
How is the injection performed?
It is done either with the patient lying on the stomach for the upper and low back pain, or for the cervical (neck area) injections – in sitting position or lying on the back, under x-ray control. The patients are monitored with EKG, blood pressure cuff and blood oxygen-monitoring device.  The skin in the back is cleaned with antiseptic solution and then the injection is carried out.
 
What should I expect after the injection?
Immediately after the injection, you may feel that your pain may be gone or quite less.  This is due to the local anesthetic injected.  This may last only for a few hours.  Your pain will return and you may have a “sore back or neck” for a day or two.  This is due to the mechanical process of needle insertion.  It is very important for you to keep a track of your pain and stiffness for the next 2 to 12 hours following injections.  Your response to the injections will determine if the facets are the cause of your pain or not.
 
What should I do after the procedure?
You should have a ride home.  We advise the patients to take it easy for a day or so after the procedure.  You may want to apply ice to the affected area.  Perform your usual activities as tolerated.
 
Can I go to work to work the next day?
Unless there are complications, you should be able to return to your work the next day. The most common thing you may feel is sore back.
 
How long does the effect of the medication last?
The immediate effect is from the local anesthetic injected.  Depending upon the medication injected, it can last from 2 hours to 8 hours.  Of course, if the facet joints are not the source of your pain, you may not have much relief.
 

How many injections do I need to have?
Usually one session is enough to determine if the facet joints are the most likely source of your pain or not.  However, the “placebo response” can be as high as 30 to 40 % and some patients may be recommended to have repeat diagnostic injections.  In addition, “False Positive” responses can occur.
 

Will the procedure help me?
If the pain is originating mostly from the facet joints, you should benefit from this procedure on a temporary basis.  Some do get a “placebo response” and others may get a “False-Positive” response.  Please remember that these are diagnostic injections only and last only for a few hours.  These are done to determine if the pain is coming from the facet joints or not, and if the pain is coming from the facet joints, we will recommend “Radio-Frequency Lesioning” – which will “numb” the same nerves for many weeks to months.
 
What are the risks and side effects?
Generally speaking, this procedure is safe.  However, with any procedure there are risks, side effects, and possibility of complications.  The most common side effect is pain – which is temporary.  The other risks involve, infection, bleeding, worsening of symptoms, spinal block, epidural block etc.  Fortunately, the serious side effects and complications are uncommon.
 
Who should not have this injection?
If you are allergic to any of the medications to be injected, if you are on a blood thinning medication (e.g. Plavix, Coumadin®), or if you have an active infection going on, you should not have the injection.
 

Call The Pain Treatment Center in Houston, Texas today to see how we can help you determine the best minimally-invasive spine treatment for your specific medical condition.

For appointments please call: 281-556-0001

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