Injections for Back Pain

What You Should Know About Injections for Back Pain

When you have back pain, it’s possible that your doctor may be getting out the needle. Injections may be used for diagnosing back pain – or for treatment of back pain.

When used to diagnose, the injection is a local anesthetic that is injected into the spine. If your back pain is gone or considerably less after the injection, then the doctor knows that the spot he injected is related to the pain.

It’s entirely possible that your medical doctor will suggest the use of injections to decrease the pain. But before this is done, your physician should know where exactly that injection should go – and why.

How are These Injections for Back Pain Given?

Injections may be focused on the nerve roots, the facets of the vertebrae (the joints), the discs or the sacroiliac joint (SI joint). But there’s a problem about these injections for back pain that many doctors realize: Analyzing information from the results of these injections can be faulty.

Here’s why this is true: how can the doctor be so sure that the injection for back pain didn’t affect the facets or the nerve roots if it was injected into the disc? These structures are so close to each other that there may have been medication transfer to them. Even doctors will tell you that injections used to determine source of pain are correct only 50% of the time!

This inaccuracy becomes part of the next problem:  the patient with back pain isn’t recovering; the treatment for back pain failed. Of course, there isn’t a 100% failure rate; some patients do get well with them.

What are the Types of Injections for Back Pain?

There are different types of injections that may be performed:

• Trigger point injections – these are very easy to place and are hard to miss

• Epidural injections – injections into the spot between the spinal canal and the nerve rootlets and the bony part of the spinal column. These are primarily for patients with sciatica.

• Intravertebral Disc Injections

• Injections into the Facet Joints

• Injections into the nerve roots

• Injections for Piriformis Syndrome

• Sacroiliac Joint Injections

• Intrathecal pumps

Trigger Point Injections

A trigger point is a taut band or ball or “mass” within the muscles that hurts when touched or pressed deeply. The trigger point refers pain to other locations as well. A trigger point can be in the hip or pelvic region and refer pain to the back. It could also be in the back and refer pain to other parts of the back.

If a doctor uses trigger point injections, he will inject the medication directly into the trigger point. A local anesthetic such as Lidocaine and sometimes a low dose of steroid are used. The fluid is injected into a muscle that is spasming. This is usually not done for sciatica, although may be done for Piriformis syndrome.

The muscle needs to be massaged or manipulated after the trigger point injection. The purpose of this is to get the medication to the entire muscle.

Trigger point injections may have side effects:

• allergic reaction

• infection

• nerve injury, resulting in loss of muscle function

• minor bleeding

Epidural Injections

Epidural injections are injections into the spine that are often given as an alternative to surgery for severe low back pain, herniated disc, spinal stenosis and degenerative disk disease. The injection contains steroids. However, the effects are not lasting, and the injections may need to be repeated.

For these injections, a needle delivers the steroid to either the vertebral joints called laminar surfaces or to the intervertebral foramen area where the nerve is compressed. Steroid injections carry risks of side effects, including:

• Nerve damage

• Infection in 5/1000 cases, which can lead to paraplegia

• Infection in the bone, causing osteomyelitis

• Infection in the meninges, leading to meningitis

• Headache

• Needle pierces the dura mater of the spinal cord

• Spinal cord injury or infarction in the spinal cord

• Cushing’s syndrome from repeated injections

It takes two days to know whether or not this type of treatment for back pain worked. Thus, it can be kind of nebulous as to whether the steroid worked, or if it was the physical therapy, painkillers, chiropractic adjustments or nutritional supplements that helped the back pain disappear.

Injections for Back Pain Use Dyes and Imaging Techniques

As mentioned before, whenever injections are used, it’s important to get the injection in the right spot. Medical science has two ways to do this:

  1. The use of an EMG needle placed into a muscle. After placement in the muscle, the patient contracts the muscle. The needle is moved if the location is not correct. This may sound like it’s going to cause more pain than what it’s worth, but as long as you have a surgeon that has done the procedure many times, the chance that he will choose the right location the very first time is quite high.
  2. The use of fluoroscopy and radiopaque dyes. In this technique, the injection is done before the fluoroscope finds out where the dye went. The other technique is preferable for most patients, as the dyes can cause unpleasant sensations.
  3. Using MRIs to assist injections, especially for Piriformis Syndrome. In this technique, MRIs were taken both before and after injections to see if the location was correct. When this method was used with Marcaine (longer acting anesthetic) and steroid, the back pain relief was a low 23%, compared with EMG-assisted injections that had twice as much relief. The down side of this is that it is very expensive.

EMG may be more effective because it teaches the patient to isolate the muscle that is causing the problem and then relax it as well.

Injections for Herniated Discs

Injections for discs should not be done unless other injections (to the facets and the sacroiliac joint have been done) have not been successful. In a discogram, a disc is injected with radioopaque dye so that the disc can be seen on x-rays or other imaging studies.

Injections for Piriformis Syndrome

These are usually a local anesthetic along with a steroid and can be done via EMG-assisted technique or MRI-assisted technique. It’s standard practice to try physical therapy and anti-inflammatory medications first, and only use the steroid injection when other treatments have failed.

Injections into the Facet Joints and Nerve Roots

All joints have the potential to degenerate with age, including the small joints that connect vertebrae to each other. If a person has had a back trauma that caused the back pain but x-rays don’t show anything, it could be that a person has facet problems. Chiropractic care relieves the pain of facet disease; this is another clue that the problem is coming from the facets.

These injections need accompanying fluoroscopy or CT scans to follow the injections to see what structures have been medicated. It may be performed with radiofrequency waves as well.

Injections can also target the nerve roots, and again, will need scans to make sure that the right area is medicated.

Sacroiliac Joint Injections

If you will be getting sacroiliac joint injections, you will have imaging studies done simultaneously to follow the injection; possibly CT scans or fluoroscopy.

Intrathecal Pumps

These are devices that pump morphine or baclofen directly into the fluid surrounding the spinal cord. This method is only for those who are bedridden and nothing else works, for example, for those who have cancer of the back.