Facet joint injections
The facet joints link together the bones in your back and help to stabilise the spine and control the degree of movement. With age, they are prone to injury and deterioration which is a common cause of the type of lower back pain which is worse while sitting and improved by walking.
An injection - a steroid medicine (which reduces inflammation) or a combination of a steroid and a local anaesthetic - may be given into a facet joint to treat the pain, inflammation and restriction of movement caused by deterioration. It can take up to a week for the full benefits of a steroid injection to be felt.
The effects of a successful injection can last anything from a few weeks to several months. Repeat injections (usually up to a maximum of three) may be possible. Facet joint injections are usually performed as an out-patient or day-case procedure with sedation. Sedative drugs relieve anxiety and cause temporary relaxation without putting you to sleep.
Less frequently, some people have the injections done under general anaesthesia. Your consultant will advise you which method is most suitable.
If a facet joint injection is successful, it may help your consultant decide whether you would benefit from further treatment. Your consultant will explain the potential benefits and risks of having facet joint injections, and will also discuss the alternatives to the procedure.
Preparing for the Procedure
The hospital will usually send you a pre-admission questionnaire. Accurate answers are important as they help us plan your care by taking into account your medical history and any previous experience of hospital treatment. You will usually be asked to complete this pre-admission questionnaire and return it to the hospital within three days.
If you are treated as an out-patient, you may not be sent a pre-admission questionnaire. Instead, you will be asked to answer the questions when you come for treatment. If you normally take medication (e.g. tablets for blood pressure) continue to take this as usual, unless your consultant specifically tells you not to. If you are unsure about taking your medication, please contact the hospital.
Before you come into hospital, you will be asked to follow some instructions:
- Have a bath or shower at home on the day of your admission
- Remove any make-up, nail varnish and jewellery
- Rings and earrings that you’d prefer not to remove can usually be covered with sticky tape
Follow the fasting instructions in your admission confirmation letter - typically, you must not eat or drink for about six hours before a general anaesthetic or sedation. Some anaesthetists allow occasional sips of water until two hours beforehand.
When you arrive at the hospital, a nurse will explain how you will be cared for during your stay and will carry out some simple tests such as checking your heart rate and blood pressure and testing your urine. Your consultant will usually visit you before the procedure.
If you are happy to proceed with the treatment, you will be asked to sign a consent form. This confirms that you have given permission for the procedure to go ahead. It is important for you to know and understand the possible side effects and complications of any procedure in order to give your consent.
Please see the relevant sections below for more information about these.
About the procedure
Immediately before the procedure, you will be asked to change into a hospital gown.
Facet joint injections are usually performed in an operating theatre, anaesthetic room or X-ray department. Before the procedure begins, you will have a small plastic tube (cannula) placed in a vein in the back of your hand. This can be used to give you sedatives, or other medicines if necessary, during your treatment. If sedative drugs are given, you will feel relaxed and drowsy almost immediately. You will be able to follow instructions given by your consultant, but may remember very little about the procedure afterwards.
Facet joint injections are usually done with you lying face down. A thin needle is passed through the skin on your back into the facet joint and the steroid and anaesthetic mixture is injected into the joint. The treatment usually only takes a few minutes and more than one joint can be injected during the same session. This procedure can be uncomfortable because the injections are given in an area that may already be painful. During the procedure, your consultant will take X-ray pictures to ensure the needle is correctly placed in the facet joint.
After the procedure
If you have had general anaesthesia or sedation, you will be taken from the operating theatre to the recovery room, where your blood pressure and heart rate will be monitored. After this you will be taken back to your room or the day-care ward where you’ll need to rest on a bed for around two hours. The nursing staff will be on hand to make sure you are comfortable. If you have had a sedative, you may doze off during this time. Painkillers will be available to relieve any discomfort. When you feel ready, you can begin to drink and eat, starting with clear fluids.
Before you leave, a nurse will give you a contact telephone number for the hospital and a date for a follow-up appointment with your consultant. This is usually about eight to ten weeks later. The effects of any sedative or general anaesthetic may last longer than you expect, so you should not drive, drink alcohol, operate machinery or sign legal documents for 48 hours. This means that you will have to arrange for someone to take you home and you should try to arrange for somebody to stay with you for the first 24 hours.
After facet joint injections, you should rest your back for 48 hours to allow the steroid to take effect. This means that you should take it easy, but you should not stay in bed. Gently moving the joints through the normal range of movements is good for you, but avoid strenuous exercise. After the first couple of days you should move your back as usual.
It is important to follow your consultant's advice about returning to work. Expect to take one or two days off, or longer if you do manual work or are on your feet all day. During the first few days, if you feel unwell or develop any of the following, please contact the hospital immediately:
- pain that does not settle or gets worse
- a fever or high temperature
What are the risks?
Having facet joint injections is generally safe. However, all medical procedures carry an element of risk which can be divided into the risk of side-effects and the risk of complications.
These are the unwanted, but usually mild and temporary effects of a successful procedure. During the first 24 hours after a facet joint injection you may feel more pain and tenderness in the area as the anaesthesia wears off. This may last for a few days and you will be given painkillers to help.
Complications, during or after facet joint injections, are rare but can be serious. A possible complication of any injection into the spine is that the treatment reaches unintended parts of the spinal cord. This can cause a drop in your blood pressure or widespread numbness. Your consultant monitors you constantly during the procedure and will provide appropriate care, should this happen.
There is a risk of infection in the joints, inflammation of the nerves in your spine, or damage to nerves or tendons near the joints being injected. If you have repeated facet joint injections you may be at risk of damage to the soft tissue or cartilage in your joints. The chance of complications depends on the type of operation you are having and other factors such as your general health. Ask your consultant to explain how these risks apply to you.
Please note this information is not intended nor implied to be a substitute for professional medical advice nor is it intended to be for medical diagnosis or treatment.