Within the arsenal of treatments that we offer when we have back pain is facet blocking. This sounds very complicated but it is very simple when we understand what the facets are and what a blockage is.
What do you mean by facetary?
Facet lock the word “facet” refers to the articular facets of the back of the vertebra (in red in the image). If we look at the vertebra, in front we have the body where the intervertebral discs that we all know are articulated. But there are more joints in the vertebra. From behind, in the area that gives to the back, there are joints that have a lot of protagonism in the back ailments. These joints, like any other, have their cartilage to allow slippage and a joint capsule that surrounds it. The particularity of these joints is that they are very rich in sensitive nerves. This makes any injury in this area can irritate these nerves and cause pain.
Lesions affecting these posterior joints produce characteristic symptoms. Usually pain is born in the affected joint and it radiates down and out. If the last vertebrae of the lumbar region are affected, there will be a pain in the lower back that radiates to the gluteus. It is not always so simple. The pain that comes from facets is sometimes local and does not radiate. At other times the pain radiates from other regions less defined as the back of the leg.
What is a nerve block?
A nerve block is a performance on the nerve that limits your ability. If we puncture an anesthetic for example, we will block the nerve that carries the sensitivity and we stop noticing that area. In other words, we will notice the sleeping zone because the sensory nerve has stopped working.
Blockages are usually performed with anesthetic agents when we want a temporary effect. Longer lasting effects can be achieved with techniques such as radiofrequency. Even in certain cases techniques are used that completely nullify the nerve function definitively.
How is facet blocking done?
The procedure consists of inserting a needle in the back until reaching the posterior joints, to those articular facets that we have discussed. For greater precision, the needle is usually guided with X-rays until it is placed in the right place. At this time the medication is introduced. The injection can be guided with other techniques such as ultrasound but nowadays are used mainly x-rays with a device called scopia.
Usually the first time we perform this block is to use an anesthetic and a corticoid. Anesthesia sleeps the nerve and the corticoid has a local anti-inflammatory effect on the nerve and surrounding structures.
If we perform a facet blockade and it is effective but only temporarily, we can consider using other more durable methods such as radiofrequency. If the anesthesia eliminates the pain it also guides us about the origin of the ailment in the cases where there are doubts. That is why it is said that the facet block is sometimes a diagnostic technique. Although it must be taken into account that if it is not effective, it does not mean that pain is not facet. Using a local anesthetic first helps us to confirm the diagnosis but, above all, confirms the effectiveness of the technique before using longer lasting blockages.
The usual procedure is to block several facets in the same procedure. This is because the same nerve can go through two facets. That is why they usually infiltrate a minimum of three levels.
What are the advantages and disadvantages of facet blocking?
We must be clear about what we are getting. What is intended is a symptomatic relief. We are infiltrating two substances. On the one hand the anesthetic will relieve the pain of the joint and the one that comes from the irritation of the nerve, but it will be transient. In a few hours the effect of the anesthesia will pass. On the other hand, the corticosteroid that is usually used is delayed release; This means that it is slowly absorbed and has a longer effect. The effect of the corticosteroid is anti-inflammatory, does not block the nerve; what it obtains is to lower the inflammation of the structures in the zone where it is applied. This can indirectly alleviate nerve irritation and improve symptoms. The corticoid has a therapeutic effect that can last from one to three months.
We cannot lose sight of the fact that we are not acting on the cause that caused the injury. It is a good technique that, if used when it is due, will improve our pain and the function of our back, but if we are not doing the rest of the things well, the problems will return.
I am going to put a simple example so that we understand it. Imagine a worker who has been moving heavy objects for 20 years and has a wear and tear on the lumbar vertebrae. If it starts with facet pain, we can relieve it with a blockage. What we are not going to stop is the wear and tear of these joints if your situation does not change. Logically over the years the situation will not go better if the habits are the same.
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