What is facet joint denervation?
Facet joint denervation is a procedure to deaden the nerves that are causing your pain. If these nerves can be broken then the brain does not receive the pain messages. The pain is therefore reduced.
Before facet denervation is considered you will have already had facet joint injections to confirm the diagnosis. Facet joint injections are also used to treat your pain. The injections are usually given into the lining of the joints. Sometimes the nerves supplying the joint are injected instead. Facet injections bathe the joints in local anaesthetic and steroid. The steroid is used to reduce inflammation. Only a small amount of steroid is needed and it will not cause any of the side effects sometimes associated with taking steroid tablets.
Quite often, facet joint injections reduce the pain and improve mobility for a period of weeks or months, only for the pain to come back. If the pain reduction from the facet joint injections is worthwhile and useful to you, then denervation is a way of making the benefits last much longer, perhaps up to several years.
For denervation the nerves that send pain messages from the joints to the brain must be identified and then denervation is carried out using a radiofrequency probe that heats the small nerve branches to each facet joint. Radiofrequency is a type of electromagnetic radiation similar to microwaves.
What has gone wrong?
You have suffered general wear and tear, called degeneration, or damage from injury, to the facet joints at the base of your spine. When the joints are inflamed, the nearby muscles can become irritated and go into spasm or cramp. You experience pain and stiffness, as movement is reduced.
The aim of the procedure is to deaden the nerves that send the pain messages from the painful joints to your brain. This reduces your low back pain. If the pain usually spreads to your buttocks, hips, groins or knees it should also be reduced.
Your pain should be reduced and you should be able to move around more easily. The physiotherapists will show you exercises to help prevent the problem happening again. If successful, this treatment can avoid the need for surgery.
Are there any alternatives?
By the time you consider facet joint denervation you should have already had facet joint injections and other simple treatments. These include rest, painkilling and anti-inflammatory tablets, and physiotherapy with exercise.
You may have also tried a transcutaneous electrical nerve stimulation (TENS) machine for your pain. This works by sending soothing electrical pulses across the surface of the skin and along the nerve fibres. These pulses prevent pain signals reaching the brain. They also stimulate your body to produce higher levels of its own natural painkillers, called endorphins.
What if you do nothing?
If you do nothing there are several things that may happen:
With time and rest the inflammation and pain may settle on its own.
The pain and difficulty in moving may remain the same.
The pain may increase and spread to other parts of your spine.
Your posture may get worse, making walking, sitting and even sleeping more difficult.
Who should have it done?
Patients with low back pain caused by painful facet joints, who have had a reduction in their low back pain after facet joint injections, should have the procedure.
Who should not have it done?
Each patient has the final decision on whether to proceed with the treatment or not. If you are unhappy about the procedure for any reason you should not continue. There are specific medical situations when facet joint denervations should not be done and they are:
If you take medication that prevents your blood from clotting, such as Warfarin. This could lead to bleeding, which can be a serious problem and must be avoided. Your doctor may still be able to do the procedure if you stop the medication a few days before but may have to do a test first to check the clotting of your blood. This will need to be discussed with your doctor.
If you have an illness that prevents your blood from clotting, such as haemophilia. This could also lead to bleeding in the spine. Again, a blood clotting test may be done first.
If you have infection of the skin where the needle is put in. This could lead to infection in the deeper tissues and possibly septicaemia.
If you have noticed a recent worsening of symptoms, especially weakness and loss of bladder or bowel control.
If you have metal implants, such as a hip replacement. Under certain circumstances this problem can be overcome, but it does need to be discussed with your doctor.
If you have an implanted pacemaker to control your heart rate.
Author: Dr Sean White FRCA. Consultant in pain and anaesthesia
© Dumas Ltd 2006