EPIDURAL STEROID INJECTIONS
It is reported than approximately 50% to 80% of adults will suffer from some form of neck or back pain over the course of their lifetime. This pain can be caused by pinched nerves, strained muscles, radiculitis, a herniated disc or normal aging of the spinal vertebrae.
Injections comprise another nonsurgical treatment option for low back and neck pain. They are typically considered as an option to treat these pain symptoms after a course of medications and/or physical therapy is completed, but before surgery is considered. Injections can be useful both for providing pain relief and as a diagnostic tool to help identify the source of the patient’s back pain.
Several common conditions that cause severe acute or chronic low back pain and/or leg pain (sciatica) from nerve irritation can be treated by steroid injections. These conditions include:
A lumbar disc herniation, where the nucleus of the disc pushes through the outer ring (the annulus) and into the spinal canal where it pressures the spinal cord and nerves.
Degenerative disc disease, where the collapse of the disc space may impinge on nerves in the lower back.
Lumbar spinal stenosis, a narrowing of the spinal canal that literally chokes off nerves and the spinal cord, causing significant pain.
Compression fractures in a vertebra.
Cysts which are in the facet joint or the nerve root and can expand to squeeze spine structures.
Annular tear, a painful condition where a tear is present in the outer layer of the disc.
Patients will find that the benefits of an epidural steroid injection include a reduction in pain, primarily in leg pain (also called sciatica or radicular pain). Patients seem to have a better response when the epidural steroid injections are coupled with an organized therapeutic exercise program. While the effects of an epidural steroid injection tend to be temporary (lasting from a week to up to a year) an epidural steroid injection can deliver substantial benefits for many patients experiencing low back pain.
When proper placement is made using fluoroscopic guidance and radiographic confirmation through the use of contrast, > 50% of patients receive some pain relief as a result of lumbar epidural steroid injections.
Pain relief is more often felt for primary radicular (leg) pain and, less prominently, low back pain.
The pain relief and control brought on by injections can improve a patient’s mental health and quality of life, minimize the need for painkiller use, and potentially delay or avoid surgery.
Diagnostically, injections can be used to help determine which structure in the back is generating pain. If lidocaine or similar numbing medication is used, and the patient feels temporary relief after an anatomic region is injected (e.g. facet joint or sacroiliac joint), it can then be inferred that the specific region is the source of the pain. When considered in conjunction with a patient’s history, physical exam, and imaging studies, injections used for diagnostic purposes can be very helpful in guiding further treatment for the patient.
Patients may be asked to change into a hospital gown, which allows for access to clean the injection area and to allow the physician to easily visualize the injection site. An epidural steroid injection usually takes between 15 and 30 minutes and follows a relatively standard protocol:
The patient lies flat on an X-ray table or with a small pillow under their stomach to slightly curve the back. If this position causes pain, the patient can be allowed to sit up or lie on their side in a slightly curled position.
The skin in the low back area is cleaned and then numbed with a local anesthetic similar to what a dentist uses.
Using fluoroscopy (live X-ray) for guidance, a needle is inserted into the skin and directed toward the epidural space. Fluoroscopy is considered important in guiding the needle into the epidural space, as controlled studies have found that medication is misplaced in many (> 30%) of epidural steroid injections that are done without fluoroscopy
Once the needle is in the proper position, contrast is injected to confirm the needle location. The epidural steroid solution is then injected. Although the steroid solution is injected slowly, most patients sense some pressure due to the amount of the solution used (which in lumber injections can range from 3mL to 10mL, depending on the approach and steroid used). The pressure of the injection is not generally painful.
Following the injection, the patient is monitored for 15 to 20 minutes before being discharged home.
Generally, there are few risks associated with epidural injections. The risks are remote and include:
A wet tap may occur, which means that the needle has penetrated the dural sac into the cerebral spinal fluid (CSF). A wet tap may result in a CSF leak and a spinal headache.
Infection into the epidural space is also a remote risk.
While there is no risk of paralysis (since the spinal cord ends at a higher level in the spine), there is a remote risk of damage to a nerve root.