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Transforaminal injection info

Transforaminal epidural injection is done for both diagnosis and treatment of pain from the lumbar spinal nerves and pain originating from the lumbar intervertebral discs. 



The main effect of a transforaminal epidural is to reduce pain, improve mobility and hasten resolution of symptoms. The duration of pain relief can last from only hours to several months and varies from patient to patient. Treatment can be repeated, and those patients who respond to TFIs usually require an average of less than two injections, and no more than four.



You must tell us if:

  • You are pregnant

  • Have allergies to iodine or shellfish

  • Have any skin infections

  • Have bleeding problems or are or blood thinners such as warfarin. 



Please arrange for a friend or relative to drive you home after your injection appointment, as you may be a little unsteady or feel slightly numb or weak to drive. 


Please STOP your normal pain medication before this procedure. You can eat and drink as normal before the procedure. 


During the procedure, you will be made comfortable and lying face down. You will be completely awake and able to listen and speak during the procedure.  


Antiseptic is applied to the skin and a sterile drape over the area. Local anaesthetic is then used to numb the area which can feel uncomfortable in the short term. The needle is then advanced down to target the painful area under x-ray guidance. 

If at any time you are concerned or want to stop the procedure you can say so.  However, this is unlikely to be necessary.


The whole procedure usually takes less than 30 minutes. 

Follow up:

After the procedure, you will be required to remain at the radiology facility for about 30mins, so the result of the block can be assessed.  


At follow-up assessments you will be asked to grade your pain level and to test if any of your Activities of Daily Living (ADLs) have been restored.  Within a short time after the block you should know if it has relieved your pain; 

  • If your pain is not relieved, don’t be afraid to say so. 

  • If only part of your pain is relieved, try to explain which part has been relieved and which part has not.  

You will be contacted the next day by telephone to assess the longer-term results of the block.


Common side effects:

Approximately 1-5 % of patients have headache and facial flushing. Both of these usually subside spontaneously within a couple of days. Allergy to the corticosteroid solution could cause an immediate hot flush or rash.

Your leg or foot could become “numb”.  This is rare but could last as long as the effect of the local anaesthetic, so you should always attend with a driver.  

Sometimes when patients obtain relief, they experience a “rebound” effect when their pain returns, that is, it feels worse at first then settles back down to the accustomed level. It is recommended that you do not undertake any extraordinary activities while the block is in effect. 


Long-term use of corticosteroids can cause problems such as thinning of skin or bone, raised blood sugars, weight gain and increased blood pressure. These effects are dose related and unlikely to be a problem unless injections are used frequently. Women may experience menstrual disturbance for a short time.


Rare Risks and Complications:

The risk of an infection from the procedure is incredibly low and likely less than 1:10,000 but please contact us immediately if any increasing pain, redness or swelling in the area.


Very rare but serious complication can occur if the wrong amounts of drugs are injected or if the drugs are accidentally injected into the wrong space such as the small arteries supplying the spinal cord.  This could include irritation or damage to the spinal cord or spinal nerves. In order to minimise the risk of injecting into blood vessels, contrast material is injected first to check and the procedure may be stopped if so. 


Some further points regarding transforaminal injection of corticosteroid

  • The procedure is to treat your leg (sciatica) pain

  • It may also help your back pain

  • It does not “cure” the underlying disc injury or degradation - this usually repairs itself in time

  • Approximately 80% of people will get a reduction of 50% or more with their pain and 50% people will have 80% or more reduction

  • The injection can be repeated if there is a good but not complete response at a subsequent date

  • If your pain is not relieved at all, then surgery may be necessary

  • If one can better control the pain then the disc will slowly stabilise and heal over time without you being in disabled by ongoing pain

  • Your leg/back pain maybe a little aggravated for several days even 4 to 5 days after the procedure before the steroid (cortisone) effect takes hold

  • If your pain is relieved it is important to continue with that level of activity you were doing whilst in pain. Excessive activity including sport/gardening/lifting may aggravate the underlying injury despite the apparent loss of pain

  • It may take a number of months for the disc to stabilise and the protrusion to resorb ie it slowly gets broken down and absorbed by the body – it does not “go” back into the disc itself

  • The injection has two components

    • Primarily it is diagnostic – ie does the anaesthetic component completely relieve your usual pain for a period of hours after the injection?

    • Secondarily it is therapeutic – ie does the steroid (cortisone) reduce the inflammatory mediated pain over the subsequent days?


If any concerns after the procedure please call The MSK Institute directly on 021 249 1110 or attend an after-hours doctor if our doctors are unavailable. 

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