The facet joint is a structure that does two things. It helps keep the spine straight and firm to hold the weight of your upper body. At the same time it allows limited movement so that you can bend, stretch and rotate.
What are facet joint injections?
Injections into the facet joints are used to treat pain in that area. The injections are usually given into the lining of the joints where there is a soft membrane called the synovium. The synovium can become inflamed and cause pain. This pain can lead to muscle spasm or tightness, which can produce even more pain.
A facet joint injection can target a painful area. The injection bathes the joints in local anaesthetic and steroid solution. Only a small amount of steroid is needed and it will not cause any of the side effects sometimes associated with taking steroid tablets. They are not the same kind of steroids that athletes may take. This steroid injection relieves pain and inflammation. Pain from inflamed joints can be treated and the muscles made to relax and work properly again.
Often, facet joint injections reduce pain and improve mobility for a period of weeks or months, only for the pain to return. If the pain reduction from facet joint injections is worthwhile and useful then facet joint denervation is a way of making the benefits last much longer, perhaps up to several years. There is a separate information leaflet for facet joint denervation within this series.
What has gone wrong?
You have suffered general wear and tear (degeneration) or damage from injury to the facet joints at the base of your spine. When the joints are inflamed, the nearby muscles become irritated and go into spasm or cramp. Movement is then reduced.
The aim of the procedure is to reduce the inflammation of the joints. This reduces the low back pain you have. If the pain usually spreads to your buttocks, hips, groins and knees it should also be reduced.
Your pain should be reduced and you should be able to move around more easily. The physiotherapist 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 that you have the facet joint injections you should have already tried other simpler treatments. These include rest, painkilling and anti-inflammatory tablets and physiotherapy with exercise.
You may also have 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?
The following groups of patients should have the procedure done:
Who should not have it done?
Each patient has the final decision on whether to proceed or not. If you are unhappy about the procedure for any reason you should not continue.
There are specific medical situations when facet joint injections should not be done and they are as follows:
When a patient is on medication that prevents blood from clotting, such as warfarin. This would lead to more bleeding than normal. It may be possible to stop the medication a few days before the procedure. This will need to be discussed with your doctor
When a patient is suffering from an illness that prevents blood from clotting, such as haemophilia. This would also lead to more bleeding than normal
When there is infection of the skin over the site where the needle needs to be put in. This could lead to infection in the deeper tissues.
When a patient has noticed a recent worsening of their symptoms, especially weakness and loss of bladder or bowel control
Author: Dr Sean White FRCA. Consultant in pain and anaesthesia
© Dumas Ltd 2006