Joint Injections

An image guided lumbar epidural corticosteroid injection is the accurate placement of a very thin needle, at a given level in this space, under guidance with computed tomography (CT) or X-ray images or pictures to inject corticosteroid (or ‘steroid’) and usually a long-acting local anaesthetic.

As you will be lying on your stomach during the procedure and will be uncomfortable if your stomach is too full, it is advisable to limit food intake to a light meal only, up to 2 hours before the procedure.

It is recommended that you do not drink anything in the 2 hours before the procedure, and you should go to the toilet right before you have the procedure. This is because the local anaesthetic used for this procedure can mean you will not feel your bladder filling as you normally do. This will wear off within an hour or two.

You should wear comfortable clothes that are easy to remove and leave jewellery at home. Please note that some of the disinfectant agents used during these procedures may stain light-coloured clothing. When you make your appointment for the image guided lumbar epidural injection, you need to let the radiology clinic or department know if you are taking any blood thinning medication, such as warfarin, clopidogrel, dabigatran, prasugrel, dipyridamole or asasantin.

Blood thinning medications may need to be stopped for a period of days, or your normal dose reduced, before this procedure is carried out. It is very important that you do not stop any of these medications or change the dose without consulting the radiology clinic and your own doctor. They will give you specific instructions about when to stop and restart the medication. These drugs are usually prescribed to prevent stroke or heart attack, so it is very important that you do not stop taking them without being instructed to do so by your doctor or the radiology practice, or both. Aspirin is usually not stopped.

A blood test may be required to check your blood clotting on the day of the procedure.

Continue with pain medication and other medications as usual.

If you have problems lying on your stomach, please advise the practice or hospital when you make your appointment, as this can make the procedure difficult and the radiologist (specialist doctor) carrying out the procedure needs to be made aware of this.

You may be monitored by nursing staff while you lie in a bed in the observation ward for approximately 2 hours before you are allowed to leave.

You will need to have someone take you home, because you are not allowed to drive immediately after the procedure.

You will be asked to change into a hospital gown and leave your belongings in a locker.

You will then be asked to lie on a table on your stomach and this table will either be in the CT scanning room or in a fluoroscopy suite. In both cases, there is equipment over or around the table that allows the radiologist to use X-rays to guide the needle placement. The table will have a thin foam mattress on it and you will have a pillow for your head.

A metal marker will be taped on the skin of your lower back and images or pictures on the fluoroscopy equipment or the CT scanner will be used to adjust the position of this marker so that it is at the correct level for the injection. The skin will be marked with a pen or felt marker to indicate where the needle will enter the skin and the metal marker will then be taken away.

The skin is cleaned with an antiseptic and a drape may be placed on your back. A local anaesthetic injection is used to numb the skin and deeper tissues. This is uncomfortable for a few seconds, producing a pin prick and a stinging sensation. You will be awake and only the area where the lumbar epidural injection is being carried out will be numb.

When the skin and muscles are numb, a thin spinal needle is then guided into the spinal canal and into the epidural space. The placement of the needle in the epidural space is checked by the radiologist by injecting contrast medium (X-ray dye) or air. Contrast medium enables the CT to show the area inside the body where the procedure is being carried out more clearly on the images.

Once it is confirmed that the needle is in the correct position, a mixture of corticosteroid and (in some radiology practices/hospitals) a long acting anaesthetic is/are then injected. The pressure of the injection may momentarily increase the pain, but this is generally quickly relieved as the local anaesthetic takes effect.

It can vary, but an ultrasound guided injection generally takes between 15 and 30 minutes.

Joint injections might cause temporary mild pain and discomfort, as the pressure of the injection may momentarily increase the pain. However, this is generally quickly relieved as the local anaesthetic takes effect.

Depending on the type of joint injections, you can expect the positive outcome (pain relief and improved mobility) to last aproximately four months.

Like any treatment, joint injections carry certain risks and side effects. Most are mild or temporary, but some can be long-lasting. Side effects can include: Cartilage damage. Joint infection. Nerve damage. Temporary facial flushing. Temporary flare of pain and inflammation in the joint. Temporary increase in blood sugar. Tendon weakening.

It may take up two days to two weeks for a succesful facet joint injection to make you feel pain relief and improve your mobility. Keep in mind that all patients react differently.