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Spinal Injections

Selective Nerve Root Block

A nerve root sleeve injection (NRSI) or nerve root block refers to an injection into the space surrounding a spinal nerve root. It can be used to diagnose (diagnostic) the source of nerve root pain as well as provide pain relief (therapeutic).

Nerve root sleeve injections are usually performed under X-ray (fluoroscopy) guidance. This aids the surgeon in accurate positioning of the needle. Depending on the location of pain, a local anesthetic is injected around the specific nerve root; it can be either in the neck (cervical) or in the back (thoracic or lumbar) region. A small amount of contrast material is injected to confirm the positioning of the needle tip. Then a local an aesthetic and steroid is injected, through the needle, to reduce inflammation and decrease your pain.

Cervical nerve root sleeve injection: For cervical nerve root sleeve injection, the patient lies on their back, on the operating table. The head is placed on a head ring. The skin on the side of your neck is anaesthetized by injecting a local an aesthetic.

Lumbar and thoracic nerve root sleeve injection: For a lumbar and thoracic nerve root sleeve injection the patient lies on their stomach, on the operating table. The skin over the lower back is then anaesthetized with a local anesthetic.

Following the injection, you will be monitored for about 30 minutes before you are discharged home. Following a sleeve injection, you may experience mild pain. You also may be referred to a physical therapist to start a physical therapy program. You should avoid driving on the day of your procedure so you will need to arrange for a ride home.

Some of the complications of NRSI include infection, bleeding, nerve injury, paralysis, and cerebrospinal fluid leakage.

Caudal Epidural Injection

The epidural cavity is the space surrounding the spinal cord, which extends from the skull to the tailbone, and consists of fat, nerves and blood vessels. Nerves in this space can be blocked by injecting an anesthetic, or a constricted nerve can be relieved of pain and inflammation by injecting steroid medication into the epidural space. Caudal epidural injections are administered at the spinal segments of the lower back and tail bone. The injection can also be used as a diagnostic tool to ascertain the location of pain caused by a nerve pinched by vertebral bone herniation or bone spurs.


Caudal epidural injections are recommended to treat conditions such as:

  • Sciatica: Weakness or pain caused by irritation of the nerve root originating from the lower back
  • Herniated/bulging disc: Vertebral discs extend beyond the vertebrae, pinching the neighboring nerve
  • Degenerative lumbar spinal stenosis: Nerve impingement caused due to narrowing of the spinal canal

Caudal epidural injection is contraindicated in those allergic to anesthetic or steroid medication.


You will lie on your abdomen on an X-ray table. Your doctor will administer intravenous medication to help you relax. Your lower back area will be numbed using local anesthesia. Your doctor then inserts a needle into your back just above your tail bone, guided by X-ray imagery. A contrast dye is injected to confirm the epidural space. Following this, your doctor injects a mixture of anesthesia and steroid medication which spreads throughout the epidural space to treat and relieve the inflammation and pain. The procedure takes about 15 minutes and you will be discharged on the same day.


After your procedure, you will be advised to rest and not drive for the next 24 hours. You can commence your normal activities after 24 hours. The effect of the medication starts working after a week, however, if you do not experience improvement within10-14 days, please consult your doctor.

Risks and complications

Complications from caudal epidural injections are very rare. There is a risk of bleeding or infection at the site of the injections and sometimes headache in case of a puncture of the dura (outer membrane of the spinal cord). You may also have allergic reactions to the medication administered.

Facet Joint Injection

Facet joint injections contain a strong anti-inflammatory agent called corticosteroid and an anesthetic for pain relief. They are given to relieve pain in the back, neck, arm and leg and even headaches caused from inflammation of the facet joints. Inflammation of the facet joints may occur due to:

  • Degenerative disease of the spine such as spinal stenosis, spondylolysis, herniated disc, arthritis and sciatica
  • Postoperative acute pain after discectomy and spinal decompression
  • Trauma to facet joint because of whiplash injuries of the neck as in a motor vehicle accident or some other traumatic event

Facet joint injections are administered into the inflamed painful facet joints. These are the joints connecting each vertebra of the spine to the vertebra below it and above it. Each vertebra has four facet joints, one pair connects to the vertebra above and the second pair connects to the vertebra below. Thus they are present on both sides of the spine from the neck to the lower back providing flexibility and smooth movement to both the neck and the spine.


Facet joint injections are recommended based on pain patterns and are used to treat pain primarily from the lumbar spine (lower back), thoracic spine (middle-back) and cervical spine (neck).


You will be taken to the pre op area where trained nursing staff will get you ready for the procedure by taking vitals and reviewing your medications. Your blood sugar and coagulation status may also be checked if needed. Then you will enter the procedure room where you will lie, usually face down, on a table.

The injection site is cleansed and injection of a local numbing agent is given in the area so that you won’t feel pain during the procedure.

A thin hollow needle is then inserted through the skin and muscles to the nerves in the facet joint. The doctor is guided by fluoroscopic X-ray to place the needle in the correct position. This system gives real time X-ray images of the position of the needle in the spine on a monitor for the surgeon to view.

A contrast material is then injected through the properly placed hollow needle to confirm that the drug flows to the affected nerve when injected.

When the doctor is satisfied with the position of the needle, the anesthetic drug and corticosteroid are injected through the same needle inserted in the spine.

You may feel some pressure during the injection but mostly the procedure is not painful. The needle is removed and the injection site is covered with a dry, sterile bandage. One or more facet joints’ may be injected depending on the location of the pain. The time for the procedure will thus depend on the number of facet joint injections required to relieve pain.

Risks and Complications

With the use of live imaging though X-ray machines, contrast dye, and physicians trained in the latest interventional techniques, complications are rare. But with all medical procedures, complications may occur.  To help minimize risk please follow all directions given to you by your care provider.  Have all your treatment options explained, so you are aware of the risks and benefits of these procedures.

Some complications may include:

Infection: Your physician cleans and sterilizes your back before every procedure to prevent this from occurring. On rare occasions oral antibiotics may be needed.

Allergic Reaction: This may occur if you have allergies to any medication used. Typically this is pre-treated and on occasion your physician may recommend medications for you to take after the procedure. Pay close attention to any rashes and difficulty in breathing because that may indicate need for emergency attention.

Worsening pain: This may occur after the procedure due to the needle puncture and can last from 3 days to a week. Usually this pain resolves and does not cause any lasting impact.
There are many side effects of corticosteroids. However, by limiting the cumulative dose of medication used, these risks are reduced. Some symptoms you may feel include:

  1. Insomnia
  2. Heart Palpitations
  3. Mood changes

Facet joint injection may take 2-7 days to show any effect.   On recurrence of pain they can be repeated again but the number of these injections you can receive in a 12 month period is limited due to the use of steroids. Your physician will discuss the possibility of repeat injections.

If initial facet injection does not reduce pain significantly, repeating the injections may not be helpful and other treatments may be necessary.

And as always, follow the instructions of your care provider and have your questions answered prior to the procedure.

Sacroiliac joint injections

The sacroiliac joint connects the lowest part of the spine, the sacrum, to the adjoining bones of the pelvis, the iliac bones, which are present on either side of the sacrum. In an adult there is minimal movement at these joints. However in a female, they play an important role during delivery where they relax and increase the flexibility of the pelvis.

An injury or arthritis can cause inflammation of the sacroiliac joints, causing pain. Sacroiliac joint injections, containing cortisone and a local anesthetic, can reduce the inflammation and decrease the intensity of pain.

The benefits of sacroiliac joint injections vary. In most patients, the pain subsides within 10-15 minutes after the injection and may provide pain relief for up to 6 months or more. In some patients, it may not provide much pain relief. In cases of recurring pain, the injection may be repeated or alternative pain management techniques will be discussed with you.

Preparation before the injection

You should inform the doctor if:

  • You have any cough, cold or any systemic or skin infection such as a wound, boil or rash as infection could spread to the spine. If necessary, the doctor will reschedule the injection for a later date once the infection resolves
  • You are a diabetic. Cortisone injections may cause transient elevation in blood sugar and may require a temporary adjustment of your blood sugar medication
  • You are on any blood thinning medication
  • You think you are pregnant


Sacroiliac joint injection is an outpatient procedure performed by a radiologist. The patient would lay face down in a CT scanner. The injection site is sterilized and local anesthetic is injected to numb the area. A fine needle is then inserted through the skin and tissues into the sacroiliac joint, under guidance from CT Fluoroscopy imaging. Once the position of the needle has been confirmed, a mixture of cortisone and local anesthetic is injected into the inflamed sacroiliac joint through the needle.

After the injection

Some patients may experience mild discomfort in the back while most patients are free from pain. Patients are able to walk freely and are observed for 10 minutes following the procedure. You should avoid driving for the rest of the day, after the injection. You may return to work the following day but strenuous activity should be avoided for the initial few days. The intensity of activities can be gradually increased over time.

Risk and complications

Sacroiliac joint injections are safe but as with other medical procedures there are risks involved. Some of the risks associated with sacroiliac joint injection include infection and nerve damage. Bleeding at the injection site is rare but can occur in patients with bleeding disorders and those on blood thinning medications.