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CT Guided Nerve Root and Facet Joint Injection 


What is it?


This procedure uses the CT images to guide the radiologist in placing a needle either adjacent to a nerve root as it leaves the spine, or into a joint in the back (facet joint). The needle allows for an injection of steroid and/or local anaesthetic for treatment of back pain and/or sciatica.


Why do I need it?


Patients with back pain that has not responded to conservative measures (e.g. medications, massage, physiotherapy) may benefit from this type of procedure. In particular, this is performed if there is evidence that the back pain is localised to a particular facet joint, or due to compression of one of the nerve roots.


The steroid component in the injection decreases the bodies’ inflammatory response which can relieve pressure on a nerve root, or relieve pain caused by degeneration.


How do I prepare for it?


Patients on blood thinning medication such as warfarin should cease and have their levels normalised prior to attending. Please discuss this with your local doctor.

You should have someone drive you home afterwards, or take public transport. If you must drive, please wait until the effects of the local anaesthetic have worn off before driving.


Please bring all your radiological examinations with you when you attend.


How is the procedure performed?


The radiologist will explain the procedure and answer any questions you may have. You will be asked to sign a standardised consent form if you are happy to proceed.


The procedure is performed with you lying face down on the CT table. An initial planning CT scan is performed to localise the affected joint or nerve root. The radiographer/radiologist will then mark the entry point on your skin with a pen. It is important to stay very still during this as any movement can disrupt the planned needle route.


The radiologist will clean the skin with an antiseptic solution and inject a small amount of local anaesthetic at the entry point in the back. The needle is then placed in the correct position using the CT images. Once there, the injection is performed, the needle is removed and a dressing placed at the entry point.


What will I feel, is it painful?


The local anaesthetic will sting for several seconds, after which you will feel no pain as the needle is placed. However, when the medication is injected, you may feel exacerbation of your back pain and you may have pins and needles down the leg. The local anaesthetic may also cause the leg or foot to feel numb. This is transient and will recover when the local anaesthetic wears off.


You may go in and out of the CT scanner several times. This is normal, and it is important to stay still during this.


The whole procedure usually takes around 10-15 minutes.


What are the risks?


Bleeding can occur but is usually self limiting. Very occasionally the bleeding may worsen the compression of a nerve root which will worsen the pain. This will resolve once the blood is absorb by the body.


Infection is rare, and may be centered on the skin or around the nerve root (arachnoiditis). Archnoiditis is minimised by CT guidance.


Unintentional injection of the nerve root itself, rather than around the nerve root can cause damage to the nerve. This can result in worsening of the pain, loss of sensation and weakness. CT guidance again minimises this risk.


How long will the effects last for?


As this is a treatment and not a cure, results are variable and usually transitory, although some patients only require a single injection for complete relief of symptoms.


Most patients get relief for months to years, while occasionally there is no benefit.


Can I get more than one level injected in a single sitting?


Yes, this is possible. However most patients prefer to have only the worst level injected initially, as this may be all that they need. The risks of having more than one level injected include a wider field of numbness post procedure and possible exacerbation of the pain over the coming 24-48 hours.


Your doctor and radiologist will discuss the pros and cons of your specific case.


Are there any upfront costs?


At Uniradiology we charge $100 per sitting for the cost of the Cortisone.


Apart from this, there are no additional costs for medicare card holders.


What if I have further questions?


Please feel free to call our staff if you have any further questions.