Facet joints are small joints at the back of the spine that provide stability and help guide motion. They are found in the neck (cervical), upper back (thoracic) and lower back (lumbar). They can become painful as a result of arthritis, injury or mechanical stress.
Two nerves called “medial branches” supply each facet joint. These nerves carry pain signals to the spinal cord and these signals will eventually reach the brain.
The facet joints and/or medial branch nerves can be injected with a local anaesthetic and/or steroid. There are two reasons for doing this:
- Diagnosis: If the local anaesthetic in the injection relieves your pain then it suggests that the facet joints are a source of your pain. This can guide future treatment such as a radiofrequency neurotomy (ablation) of medial branch nerves that can provide longer-term relief from facet joint pain.
- Therapy: The steroid in the injection can reduce inflammation, reduce medial branch nerve sensitivity and provide longer lasting pain relief. The duration of pain relief may vary from days to months.
How long will the pain relief last after a medial branch block or facet joint block?
The duration of effect of the local anaesthetic in the diagnostic (test) injections is for approximately 6-12 hours. The addition of a corticosteroid to a facet joint injection may provide longer lasting relief (days – months).
As medial branch blocks and facets joint injections are primarily diagnostic procedures, if they temporarily reduce your pain after the procedure you will need to arrange a radiofrequency ablation (neurotomy) for longer-term pain relief.
Will I be awake during the procedure?
You will be offered sedation. Most people choose to be sedated to avoid discomfort. You will likely have little or no memory of the procedure, however this is not guaranteed (especially if a deeper sedation is not safe for you).
Is the procedure painful?
Local anaesthetic (numbing) injections are administered at the start of the procedure. You may experience some discomfort during the procedure.
How do I prepare for the procedure?
Please advise our medical specialists if you are:
- Taking blood thinners. These are usually OK to continue.
- Pregnant (or any chance of you being pregnant).
- Allergic to iodine, latex, shellfish, local anaesthetics, or anything else.
- Unwell (especially if you have an infection).
- Implanted with a medical device.
Our medical specialists may advise you to:
- Avoid eating for 6 hours prior to the procedure (You will be told the exact time to start fasting).
- In most cases it is OK to drink clear fluids until 3 hours prior to your procedure time (eg. water, clear cordial, black tea).
- Take your usual medications (unless advised otherwise).
- Arrange for someone to accompany you home and remain with you for that evening.
What does the procedure involve?
After arriving and completing the necessary paperwork:
- You will be asked to change into a hospital gown
- If you are having sedation then you will meet the anaesthetist and he/she will speak with you about the anaesthetic.
- A small cannula may be inserted into one of your veins.
- You may be given a mild sedative.
- Your heart rate, blood pressure, and oxygen levels are monitored throughout the procedure.
- You will lie face-down on an x-ray table, the skin over the area to be injected is cleaned with an antiseptic solution, and sterile drapes applied
- An x-ray machine is used to guide a small needle towards the correct target. X-ray dye (contrast) may be used to confirm the position of the needle.
- The local anaesthetic and/or steroid solution is injected.
- Multiple injections may be required.
- The procedure usually takes 15 to 30 minutes, plus recovery time.
What are the potential complications?
This procedure is generally very safe; however all invasive procedures carry the risk of complications. In general the risk is low, but includes:
- Discomfort at the site of the injection
- Temporary muscle weakness
- Allergic reaction to the medications.
- Failure of the procedure to reduce your pain.
- Steroid-related side effects such as transient flushing, mood swings, high blood sugar levels (especially in diabetic patients). The manufacturer did not specifically design most steroid solutions for this procedure. Despite this, these medications have been widely used, over many years, for this procedure without significant complications.
- More severe side effects are extremely rare and will be discussed with you during the consent process.
- Risks of sedation: Please ask your doctor or anaesthetist.
What happens after the procedure?
- You will be monitored in a recovery area until you are ready to go home (usually 60-90 minutes).
- You need to have someone take you home and stay with you overnight.
- If you have received any sedation during your procedure, the effects of these medications may last for up to 24 hours. You may not remember some of the information given during the procedure. This is a normal side effect of the medication. For the next 24 hours you should not drive a vehicle, drink alcohol, operate machinery, make important decisions, sign legal documents or travel unaccompanied
- Please remove any dressing the day after the procedure, when you next wash.
- The pain may return when the local anaesthetic wears off. If necessary, an ice pack can be applied to the area, 10 minutes at a time, for 24 hours following the procedure. You can take simple pain-killers such as paracetamol to help ease any discomfort.
- Remember these are diagnostic injections (tests) and if positive then you will need to arrange a radiofrequency ablation (neurotomy) for longer-term pain relief
- If steroids are injected then it may take several days for the benefits to be noticed.
- You may resume your usual activities as you feel able. This is generally the next day.
- You may be given a pain relief chart to fill out. Please keep this handy to refer to when you are phoned by the QPain nurse (within 24-48hrs) to discuss the outcome and to organise any follow up appointments.
- If you have severe pain, or notice any swelling, discharge or bleeding from the site or have any other concerns, please contact QPain, your General Practitioner, or the Emergency Department of your local hospital.
It is important that you are fully informed before you request to have any procedure. Please discuss with your doctor any questions or concerns that you may have about your procedure or this information sheet.
If you request to have the procedure, you will be asked to sign a consent form that states that you have been informed about the potential benefits, risks, alternatives, and what the most likely course of events are if you do not want to go ahead with the procedure. You can withdraw consent at any stage up to the start of the procedure.
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