Spine Information
Spinal Injections
Table of Contents
In many cases of chronic back pain spinal injections may be used
both to find out what is causing your pain and to treat your pain.
Doctors refer to these two separate uses of spinal injections as
diagnostic and therapeutic. If an injection provides pain relief in the
area that is injected, it is likely that this particular area is the
source of the problem. Injections are also therapeutic in that they can
provide temporary relief from pain.
Learn about spinal injections including
- what medications are injected
- what types of injections are used
- why you might choose to have an injection
- why you might choose not to have an injection
With most spinal injections, a local anesthetic (numbing medication)
called lidocaine (also known as Xylocaine) is injected into a specific
area of the spine. Lidocaine is a fast-acting drug, but the effects
wear off within about two hours. That is why lidocaine is used more
often as a diagnostic tool rather than a long-lasting pain reliever.
Bupivacaine (also known as Marcaine) is another type of anesthetic that
can be used. It is slower to take effect, but it lasts longer, giving
the patient more relief from pain.
Cortisone is a strong anti-inflammatory steroid medication. It is
commonly injected along with a local anesthetic in order to reduce
inflammation in the affected areas. Cortisone is long lasting and can
be slow-releasing in order to give the best possible benefits of pain
relief. Cortisone may not begin working for several days following the
injection, but the effects can last for months. Sometimes a narcotic
medication such as morphine or fentanyl is mixed with cortisone and the
anesthetic to get increased pain relief.
An ESI is a common type of injection that is given to provide relief
from certain types of low back and neck pain. The "epidural space" is
the space between the covering of the spinal cord (dura mater) and the
inside of the bony spinal canal. It runs the entire length of your
spine. When injected into this area the medication moves freely up and
down the spine to coat the nerve roots and the outside lining of the
facet joints near the area of injection. For example, if the injection
is given in the lumbar spine, the medication will usually affect the
entire lower portion of the spine.
The epidural needle is inserted into the back until the doctor feels
sure it is in the epidural space. The doctor will then place a small
amount of lidocaine into the epidural space and wait to see if you feel
warmth and numbness in your legs. If so, the needle is most likely in
the correct position. The remainder of the medication is injected and
the needle is withdrawn.
There are three different ways to perform an epidural injection:
- caudal block
- translumbar
- transforaminal
Caudal Block
A caudal block is placed through the sacral gap (a space below the
lumbar spine near the sacrum). The injection is placed into the
epidural space. This type of block usually affects the spinal nerves at
the end of the spinal canal near the sacrum. This collection of nerves
is called the cauda equina. One of the benefits of this type of
injection is less chance of puncturing the dura.
Translumbar
The translumbar approach is the most common way of performing an
epidural injection. This type of injection is performed by placing a
needle between two vertebrae from the back. The needle is inserted
between the spinous processes of two vertebrae. You can actually feel
the bumps that make up the spinous process by feeling along the back of
your spine.
Transforaminal
The transforaminal approach is a very selective injection around a specific
nerve root. The foraminae
are small openings between your vertebrae through which the nerve roots
exit the spinal canal and enter the body. By injecting medication
around a specific nerve root, the doctor can determine if this nerve
root is causing the problem. This type of epidural injection is used
most often for diagnostic purposes, and it is commonly used in the neck.
Facet joint injections are used to localize and treat low back pain caused
by problems of the facet joints.
These joints are located on each side of the vertebrae. They join the
vertebrae together and allow the spine to move with flexibility. The
facet joint injections form a pain block that allows the doctor to
confirm that a facet joint is causing the pain. The medication used also decreases inflammation that occurs in the joint from arthritis and joint degeneration.
It is important to make sure that the injection goes directly into
the facet joint. Fluoroscopy can be used to confirm that the needle is
in the right position before any medication is injected. A fluoroscope
uses X-rays to show a TV image. You doctor can watch on the screen as
the needle is placed into the joint and magnify the image to increase
accuracy.
There are two types of facet joint injections.
- Interarticular are injected directly into the joint to block the pain and reduce inflammation.
- Nerve blocks help determine whether the joint is indeed a source of
pain by blocking the small nerves that connect with the joint.
Specific Indications
A facet joint injection is perhaps the best way to diagnose facet
joint syndrome. Joints that look abnormal on an X-ray may in fact be
painless, while joints that look fine may actually be a source of pain.
This is a rather simple procedure with little risk.
Your doctor may need to determine whether the metal hardware that
has been used during surgery could be causing your discomfort. A
hardware injection is performed by injecting lidocaine alongside the
spinal hardware that was placed in the spine during surgery. If the
pain is removed temporarily by the injection, it may indicate that the
hardware is causing your pain.
Specific Indications
These injections are used to determine whether a specific piece of
hardware is causing the pain and needs to be removed surgically.
Sacroiliac (SI) joint pain is easily confused with back pain from
the spine. The SI joint is located between the sacrum and pelvic bones.
Sometimes injecting the SI joint with lidocaine may help your doctor
determine whether the SI joint is the source of your pain. If the joint
is injected and your pain does not go away, it is probably coming from
somewhere else. If the pain goes away immediately, your doctor may also
inject cortisone into the joint before removing the needle. Cortisone
is added to treat inflammation from SI joint arthritis. The injection
usually gives temporary relief for several weeks or months.
Specific Indications
SI joint injections can be used both to treat pain and to determine
the source of the pain. This injection usually requires the use of
fluoroscopic guidance or a CT scan in order to make sure the needle is placed correctly in the joint.
Various types of injections into certain areas of the lower
extremities can help your doctor decide where the pain is starting.
Pain that comes from problems with the back and the spinal nerves can
mimic many other conditions. Sometimes it is impossible to tell if the
pain you are experiencing is due to a back condition or a problem in
your hip, knee, or foot.
To help determine whether a joint of your lower limb is causing you
pain, your doctor may suggest injecting medication, such as lidocaine,
into the joint to numb the area. Once the medication is injected, if
the pain goes away immediately, that joint is more likely to be the
source of the pain than your back. Your doctor can then focus on
finding the problem in the joint.
When certain medical conditions are present, doctors may determine
it is unsafe to perform a spinal injection. Your doctor will discuss
any concerns with you before making a final decision.
Bleeding Tendencies
If you have a tendency to heavy bleeding or are on anti-coagulant
therapy (medication that prevents blood clotting), you are not a good
candidate for spinal injections. The physician might ask you to stop
all medications such as aspirin and ibuprofen five days before the
injection. These medications can decrease the ability of the blood to
clot and lead to problems. Make sure your provider has a list of your
medications well ahead of your scheduled procedure.
Infections If you have a local or systemic infection, a
spinal injection may put you at greater risk for spreading the
infection into the spine, causing meningitis (inflammation in the
covering that surrounds the spinal cord). Make sure to tell your health
care provider if you have any infected wounds, boils, or rashes
anywhere on your body.
Unstable Medical Conditions
Injections are usually an elective procedure offered to patients
without life-threatening conditions. A medically unstable patient
should have his or her medical condition treated before any elective
injections are given.
Consider these basic warnings before choosing to have a spinal injection.
- If you are chronically taking a platelet-inhibiting drug, such as aspirin
or NSAIDs (non-steroidal anti-inflammatory drugs), you have an increased
risk of bleeding and might not be a candidate for a spinal injection.
- If you are hypersensitive or have certain allergies to medications,
you may have a negative reaction to the drugs used in the injection. Make
sure to give your provider a list of your allergies.
- If you have an accompanying medical illness, you should discuss the
risks of spinal injections with your physician. For instance, patients
with diabetes mellitus might experience an increase in blood sugar after
an injection with cortisone. Patients with congestive heart failure, renal
failure, hypertension, or a significant cardiac disease may have problems
due to the effects of fluid retention several days after an injection.
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