What is a lumbar facet joint block?
A lumbar facet joint block is a surgically invasive procedure performed by injecting in to the lumbar (lower back) facet joint or injecting close to the nerves supplying the joint.
Facet joints are small joints at each segment of the spine that provide stability and help guide motion. These joints can become a source of pain due to arthritis of the spine, a back injury or a mechanical stress to the back.
Why is the lumbar facet joint block performed?
A lumbar facet joint block injection is normally performed to achieve one of the two below listed goals:
- Diagnostic goals: The immediate pain relief experienced by the patient by placing the numbing medicine into the joint confirms the joint as the source of pain.
Pain relief goals: A lumbar facet joint block also includes injecting time-release cortisone into the facet joint to reduce inflammation, often providing long-term pain-relief.
What is the procedure?
A lumbar facet joint block is most commonly performed using fluoroscopy (live x-ray) for guidance, to properly target and place the needle.
As laid down, the general injection procedure follows the below steps:
An IV line will be started so that adequate relaxation medicine can be administered, if required.
The patient is then required to lie face down on an x-ray table and the skin over the area to be treated is cleaned properly.
The physician numbs a small area of the skin with an anesthetic. This is likely to sting for a few seconds.
Using x-ray guidance (fluoroscopy), the physician directs a small needle into the joint. Several drops of contrast dye are then injected to confirm that the medicine only goes into the joint.
A small mixture of anesthetic and anti-inflammatory medication is slowly injected into the joint.
The injection takes only a few minutes. However, the entire procedure usually takes between thirty and sixty minutes.
What happens after the procedure?
After the procedure is over, the patient is required to rest on the table for twenty to thirty minutes and is then asked to move the affected area. This is done in order to provoke the usual pain.
Some patients might not experience pain relief in the immediate first few hours after the injection, depending upon whether or not the joints that were injected are the main source of pain.
Occasionally, the patient might feel some numbness or experience a slightly weak or odd feeling in the upper back for a few hours after the injection.
Should I take any precautions?
Patients about to undergo a lumbar facet joint block are generally advised to take the following precautions:
To avoid strenuous activities on the day of the injection
To avoid driving on the day of the injection without the doctor’s permission
To avoid driving for at least 24 hours after the injections if sedation was given
What are the risk factors?
The general risk involved with a lumbar facet joint block is relatively quite low. However, a patient might experience one of the below reactions or side effects:
Worsening of pain symptoms
Discomfort at the point of injection
Elevated blood pressure
Nerve or spinal cord damage