Common types of injections for back pain relief include:
Epidural steroid injection |Selective nerve root block (SNRB) | Facet joint block | Facet rhizotomy | Sacroiliac joint block
Technique
Elective spinal injections should be performed with imaging guidance, such as fluoroscopy or the use of a radiocontrast agent, unless that guidance is contraindicated. Imaging guidance ensures the correct placement of the needle and maximizes the physician's ability to make an accurate diagnosis and administer effective therapy. Without imaging, the risk increases for the injection to be incorrectly placed, and this would in turn lower the therapy's efficacy and increase subsequent risk of need for more treatment. While traditional techniques without image guidance, also known as "blind injections", can assure a degree of accuracy using anatomical landmarks, it has been shown in studies that image guidance provides much more reliable localization and accuracy in comparison.
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Selective nerve root block (SNRB)
Cervical selective nerve root block, or SNRB, is an injection used to identify the source of nerve pain in the neck and sometimes to also provide longer-term pain relief.
Nerve pain in the neck that radiates down into the shoulders, arms, and hands can develop when a cervical nerve root is compressed or inflamed due to a degenerated or herniated disc, spinal stenosis, or other degenerative spinal changes.
As the procedure begins:
- The patient lies face-down and may receive a sedative.
- The doctor injects a local anesthetic into the skin over the area that is suspected of being the source of nerve pain.
- Under X-ray guidance, the doctor injects a contrast dye to aid in correct placement of the needle at or near the suspected compressed or irritated nerves.
- Once the needle is safely positioned, there is a second injection into the nerve root where it exits the foramen, a side opening where two vertebrae meet.
- This injection contains both lidocaine, a type of anesthetic, and a steroid, such as cortisone.
- If the patient's nerve pain disappears when the anesthetic is injected, then the correct nerve root has been identified.
The steroid injection often works for a longer period of time than the anesthetic, helping to reduce inflammation and promote healing of irritated nerve roots.
The injection site is bandaged. Patients can usually leave the hospital the same day.
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Facet joint block
Facet joint injections are used to alleviate symptoms of facet joint syndrome.
The procedure typically takes 15–20 minutes, and usually uses local anesthetic. Using modern X-ray technology, multiple x-ray snapshots are taken during the procedure to ensure that the needle and injected agents are being directed into the correct location. After the procedure, it can take up to two weeks to achieve relief from the symptoms. Relief varies by patient, and can last from the negligible up to 14 months.
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Facet rhizotomy
Radio frequency lesioning is an outpatient procedure using a specialized machine to interrupt nerve conduction on a semi-permanent basis. The nerves are usually blocked for 6–9 months. The procedure is typically used to treat pain of joints in the spine. It is also sometimes known as a facet rhizotomy.
Procedure
The procedure is performed in a fluoroscopy room. Fluoroscopy identifies bony landmarks that allows the physician to localize the relevant nerves. Numbing medication is normally injected before the radiofrequency needle is inserted. After confirmation that the needle tip is positioned correctly, an electrode is inserted into the needle. Usingelectrical stimulation, the correct nerve is identified by the patient in response to a "tingling" or "buzzing" sensation. This sensation does not typically produce any pain.
A small electric current from the radiofreqeuncy lesion generator (a computer) is passed through the needle. The nerves are treated with precise controls by a physician while the needle is inserted into the body. The tissues surrounding the needle tip are then heated where electric current is passed using the radiofrequency machine for 60 to 120 seconds. This will numb the nerves. The needle is withdrawn and if successful the nerve branches have been denatured to the point where pain-generating signal is interrupted.
Lesioning most commonly occurs at the medial branch nerves of the cervical, lumbar and thoracic spine. This is a common procedure to alleviate back pain brought on bydegenerative disc disease, facet arthropathy or generalized facet disease.
Typically, a procedure such as this is preceded by nerve stimulation to confirm accurate localization of the nerves.
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Sacroiliac joint block
A sacroiliac (SI) joint injection—also called a sacroiliac joint block—is primarily used either to diagnose or treat low back pain and/or sciatica symptoms associated with sacroiliac joint dysfunction.
The sacroiliac joints lie next to the spine and connect the sacrum with the hip on both sides. There are two sacroiliac joints, one on the right and one on the left. Joint inflammation and/or dysfunction in this area can cause pain.
The purpose of a sacroiliac joint injection is two-fold: to diagnose the source of a patient's pain, and to provide therapeutic pain relief. At times, these are separated and a patient will undergo a purely diagnostic or therapeutic injection, although often the two are combined into one injection.