Spinal injections are used in two ways – diagnostically and therapeutically:
- Diagnostic injections are used to diagnose the source of back, neck, leg or arm pain.
- Therapeutic injections are used to relieve pain. They are normally used alongside exercises to improve mobility and strengthen the spine. If a diagnostic injection is used to confirm the diagnosis of a particular condition the same injection may be performed therapeutically to treat it.
Spinal injections are carried out using a special type of X-ray called fluoroscopy. The X-ray allows the doctor to see inside your joint so the needle can be guided to precisely the right place.
This helps to improve both effectiveness and safety of the procedure. A small amount of dye is injected prior to any medication to check that it flows to the right place.
If not, the doctor can adjust the position of the needle to make sure the medication goes to exactly where it is needed. Once the optimum position has been achieved, the medication is injected.
These are used to treat pain that starts in the spine and radiates out to an arm or leg. This is normally caused by a compressed or inflamed nerve.
The needle is inserted into the epidural space, which is just outside the membrane that protects the spinal cord.
If used diagnostically, an epidural injection can determine if a particular nerve is the source of the pain. In this instance, anaesthetic only may be injected and if it results in alleviation of pain, this will confirm that the nerve is the source of the problem.
However, if there is only a slight reduction in pain this will show that there is another source, requiring further investigation. If used therapeutically, an epidural can reduce inflammation and lessen or alleviate pain.
These are used to treat lower and middle back pain and neck pain which may also radiate into the buttocks, upper legs and shoulders.
Medial branch injections are often used to treat the pain of degenerative conditions such as arthritis, or back injuries. The needle is inserted into and around the medial branch of the posterior ramus (nerve), that supplies the facet joint. These are the small joints in between each vertebra.
This type of injection may also be used diagnostically. When used in this way, anaesthetic is injected around the medial branches of the nerve. If this alleviates pain it will confirm that the area injected is the source of the pain.
However, if the pain only lessens slightly or is unaffected then the source of the pain may be elsewhere. A diagnostic medial branch injection may be followed up by another therapeutic injection into the same location.
If this is successful, radio frequency ablation or a burning procedure to damage the nerves that supply the joint as a way of permanently blocking pain signals.
The sacroiliac joint is located between the ilium (pelvic) bones and the sacrum. Problems in this area can cause lower back, buttock and leg pain. Normally the pain will be on one side, depending which sacroiliac joint is affected.
To diagnose whether the sacroiliac joint is the pain source, your doctor may inject anaesthetic into the area. If there is a marked reduction in pain in the lower back, buttock or upper leg, this will confirm the diagnosis.
You may then be given a therapeutic sacroiliac joint injection using a mix of steroid medication and anaesthetic to provide longer-term pain relief.
This is a spinal injection that is only used for diagnosis rather than treatment of pain. The aim is to try to locate the source of longstanding back pain that has failed to respond to a range of treatments.
The procedure is normally only performed in preparation for surgical treatment as it can severely aggravate existing back pain. It involves injecting a liquid into the centre of the intervertebral disk to stimulate a pain response.
More than one disk will be injected to compare the problem disk with one without symptoms. This is a relatively uncommon procedure.