Back Pain Management - The Benefits and Risks of Injections

In the majority of back pain cases, outbreaks of pain and discomfort are due to sprains and strains of the muscles and ligaments, which will self-heal over the course of a few weeks. In a smaller percentage of cases, back pain will linger for more than a few weeks, but will resolve over a few months of physical therapy. In an even smaller percentage of cases, back pain will linger after conservative treatments have failed to resolve the issue, and other treatments - such as injections - may be applied to try to manage pain. Injections are delivered into the dural areas of the spinal canal, in order to block the transmission of pain signals from reaching the brain. Though doctors will try to eliminate the cause of the patient's pain through conservative treatments such as massage therapy and physical therapy, there will be cases where the patient is in extreme pain and is in need of these types of treatments. Pain management injections may serve both diagnostic and therapeutic purposes. As a diagnostic tool, the injection of an anesthetic into certain areas of the spine may help doctors to make the determination that the source of the patient's pain is at that level of the spine. If the injection of the anesthetic makes the pain go away or diminish, than that injection would be of a very useful diagnostic quality, helping doctors to determine that the pain is coming from the nerves in that area of the spine. Typically, if the injection of the anesthetic is successful in numbing the pain in that area, then the doctors will then deliver a second injection of corticosteroids in that same area in order to provide the patient with long term back pain relief. If these series of injections is successful, then the patient may expect pain relief from three months to up to a year.

While injections are associated with high success rates and treatment benefits that last up to several months, there are complications and side effects associated with them, especially after multiple injections have occurred in the same area. Short term risks of this type of treatments include infections associated with the puncture of the skin, neurologic symptoms related to the puncture of the spinal canal (spinal headache), and the destruction of the affected tissues due to repeated treatments of steroids to the same area. Tissue destruction of the affected tissues associated with the delivery of the steroid medication are more likely to occur as the frequency of treatments within a given timeframe increase. Medical standards for these types of treatments state that injections should not be given more than X times per year and X times in a lifetime. Here's some more information about the benefits and risks of injections in back pain management.

The benefits and risk of injections to treat chronic back pain include a spinal headache and infection.

Injections into the dura of the spinal canal and near other soft tissues of the spine may be beneficial to the patient, both as a diagnostic tool and to treat severe or chronic back pain. Injections may be useful towards back pain management for three reasons:
  1. Because this form of treatment involves much smaller doses of medications. Other medications are typically taken orally, where they are absorbed in the stomach and the small intestine. Oral delivery of medications involve absorption into the bloodstream, where they may affect multiple organ systems. Also, orally delivered medications must be excreted using the liver and kidneys, possible causing damage to these organs from overuse or long term use. Medications delivered by injection, on the other hand, remain limited to the area around the joint. Thus, these medications are not absorbed into the bloodstream, and don't affect the kidneys, liver, or any other structures other than those around the site of injection.
  2. Injections are useful as a diagnostic tool, because the results of the treatment may help to confirm a particular area of interest as the main pain generator. The pain generator is the structure or section along a structure that is causing the pain or referred pain. Certain therapies, such as medications, affect the entire body - so even if they work, they might not tell doctors much about the actual source of the pain. We also know that just because arthritic changes are positively found on an X-ray or MRI, it doesn't necessarily indicate those degenerative changes to be the cause of the back pain. If a particular location is identified as the probable cause of pain, then that location may be targeted for injection. If the injection procedure is successful at providing the patient with back pain relief, then the doctor will know that that site is the generator of the pain.
  3. The benefits of injections may be long lasting. Patients receive an injection treatment may experience pain relief for several months and even up to a year.

Types of injections: The types of injections used for back pain depend on the type of back pain (somatic or neuropathic) and the area of the spine or body that are affected. The most common types of injections include epidural steroid injections, sacroiliac joint blocks, facet rhizotomy, and selective nerve root blocks. Technically, these treatments are considered a surgical procedure, because they involve punctures of the skin into the bones, nerves, muscles, and soft tissues of the spine. The risks associated with these injections involve infections inherently associated with needle punctures, damages caused by the insertion of the needle into the wrong area, and possible destruction of tissue as a result of the chemicals being rejected. Here are the possible risks of injections.
  • Infection: Infections are very rare, occurring in only about 1/10th of one percent of all cases.
  • Dural Puncture ("spinal headache" or "wet tap"): There are protective layers that surround the spinal cord, called the meninges that protect the spinal cord. Between two of these layers, cerebrospinal fluid protects the spinal cord in addition to delivering oxygen and nutrients to it. If a needle puncture into the spinal canal causes a leak of this fluid into another layer of the meninges or out of the spinal canal, the result may be a condition known as a spinal headache. Symptoms of a spinal headache include nausea and a physical headache. This condition usually resolves itself in a few days without any required treatment.