July 16, 2015

Interventional Spinal Injection Techniques

Injections are a fairly conservative treatment option for lower back pain. They are usually used after a course of medications and/or physical therapy is completed (or at times in conjunction with one of these treatments), but before surgery is determined. Injections can be both useful for providing pain relief and as a diagnostic tool to help identify the source of your back pain.

Injections can be more effective than an oral medication because they deliver medication directly to the area that is generating the pain. Usually, a steroid medication is injected to deliver a powerful anti-inflammatory solution directly to the area that is thought to be the source of your pain. Depending on the type of injection you receive, long-lasting pain relief may be obtained, or your relief may be only temporary.

For diagnostic purposes, injections can be used to help determine which structure in the back is generating your pain. If lidocaine or a similar numbing medication is used, and you feel temporary relief after an anatomic region is injected, such as a facet joint or sacroiliac joint. From your reaction, it can then be inferred that the specific region is the source of your pain. When considered along with your history, physical exam, and imaging studies, injections used for these purposes can be very helpful in helping to determine the right course of treatment for you.

Common Injections include:
  • Epidural (GO TO▼)
  • Selective nerve root block (GO TO▼)
  • Facet joint block (GO TO▼)
  • Sacroiliac joint block (GO TO▼)

You can also read our list of Frequently Asked Questions (GO TO▼)

EPIDURAL SPINAL INJECTION

What is an epidural?

An Epidural Steroid Injection (ESI) involves injecting a steroid directly around the dura, which is the sac around the nerve roots that contains cerebrospinal fluid (the fluids that the nerve roots are bathed in). This may be performed at the cervical, thoracic, or lumbar level, or using a per caudal approach.
epidural injection

How does an epidural work?

Injecting around the dura sac can decrease inflammation associated with common conditions such as spinal stenosis, disc herniation, or degenerative disc disease. It is also thought that there is a flushing effect from the injection that helps to remove or “flush out” inflammatory proteins around the structures that may cause pain.

How is the injection administered?

You are placed onto your stomach on a procedure table, and a local numbing medicine is injected into the area we are targeting. Fluoroscopy (live x-ray) is used to make sure the physician is in the right place. After the initial numbing medicine, a longer needle is used to administer the medication and/or steroid to the desired area. Sometimes intravenous medication may be given to help you relax or minimize your discomfort during the injection. If medication is given to you, you MUST have an escort to drive you home. You may not drive yourself.

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SELECTIVE NERVE ROOT BLOCK

What is a Selective Nerve Root Block?

Another common injection, a selective nerve root block (SNRB) is primarily used to diagnose the specific source of nerve root pain. Secondarily, it can provide therapeutic relief of low back pain and/or leg pain.

injection2

How does a selective nerve root block work?

When a nerve root becomes compressed and inflamed, it can produce back and/or leg pain. Your imaging study may not clearly show which nerve is causing the pain, in which case a selective nerve root block can be performed to assist the physician in isolating the source of your pain. In addition to its diagnostic function, this type of an injection can also be useful for treatment of certain disc herniation.

What happens during a selective nerve root block injection?

You are placed onto your stomach on a procedure table, and a local numbing medicine is injected into the area we are targeting. Fluoroscopy (live x-ray) is used to make sure the physician is injecting the medicine in the right place. The nerve is approached at the level where it exits the foramen (the hole between the vertebral bodies). Usually a steroid (anti-inflammatory medication) and lidocaine (a numbing agent) are used. Sometimes intravenous medication may be given to help you relax or minimize your discomfort during the injection. If medication is given to you, you MUST have an escort to drive you home. You may not drive yourself.

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FACET JOINT INJECTION

What is a facet joint block?

In cases where the facet joint itself is the pain generator, a facet block injection can be performed to alleviate your pain. Similar to the selective nerve root block, facet block injections are a diagnostic tool used to isolate and confirm the specific source of your pain. Facet blocks also have a therapeutic effect as they numb the source of your pain and soothe the inflammation present. These injections may be performed at the cervical, thoracic, or lumbar regions of your spine.

injection3

What happens during a facet joint block injection?

You are placed either onto your stomach or your back on a procedure table and a local numbing medicine is injected into the area we are targeting. Once again, the physician will use fluoroscopy (live x-ray) to guide the needle into the facet joint capsule to inject lidocaine (numbing agent) and/or a steroid (an anti-inflammatory medication). If your pain goes away after the injection, it can be inferred that the pain generator is that specific facet joint capsule that has just been injected. Sometimes intravenous medication may be given to help you relax or minimize your discomfort during the injection. If medication is given to you, you must have an escort to drive you home. You may not drive yourself.

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SACROILIAC JOINT BLOCK

sacroiliac_joint

Sacroiliac (SI) joint blocks are injections that are primarily used for diagnosing and treating low back pain associated with sacroiliac joint dysfunction. The SI joint lies next to the spine and connects the sacrum (bottom of your spine) with the pelvis (hip).

What happens during a sacroiliac joint block injection?

In the SI joint block approach, the physician will use fluoroscopy (live x-ray) and insert a needle into your sacroiliac joint to inject lidocaine (a numbing agent) and a steroid (an anti-inflammatory medication). Once again, if you receive any intravenous medication to help you relax or to minimize the discomfort of the injection, you MUST have an escort to drive you home.

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FREQUENTLY ASKED QUESTIONS

How long does the actual injection procedure take?

The procedure can be performed in about ten to fifteen minutes. Afterward, you’ll be in our recovery room for an additional period of about 10 minutes, where you can have a snack and something to drink. You’ll then be given discharge instructions by the RN. You will be asked to complete a pain diary after the injection, charting your response to the injection you just received. You may feel extra pain initially after the injection, but this should subside. You may then be scheduled for additional injections, as these injections are usually done in a series of three. You WILL be required to have an escort drive you home.

What are the risks associated with injections?

As with any minimally invasive procedure, there is a very slight risk of infection at the puncture site, swelling, bruising, and increased pain or a change in the character of your pain. There is also a remote risk that the needle might enter the dural sac (except with facet injections) into the cerebral spinal fluid, which may result in a spinal headache. Steps are taken to minimize your risks and maximize the efficacy of treatment.

What can I do to prepare for an injection?

You should wear comfortable clothes to the surgery center, and leave valuables at home. You must have a driver to take you home after the injection. You will need to fast — no food or drink — for four hours before the injection. You may however take all of your regular medications with a small drink of water.

You will be contacted by a registered nurse prior to your injection to briefly review your history and review the pre-procedure instructions. Please call the Spine Institute Northwest at (425) 486-1000 with any questions you might have PRIOR to the procedure day so that we can address any issues or concerns you may have.

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