An epidural injection involves the injection of a therapeutic substance into the space that surrounds the spinal cord, nerve roots and the posterior aspect of the discs. These injections can provide temporary or prolonged relief from pain and inflammation caused by compression or irritation of spinal nerves from bulging discs (disc herniation's) or narrowed canals (spinal stenosis). They can also decrease the pain from discs themselves (discogenic pain).
The needle is guided into location with the use of fluoroscopy (x-ray guidance). X-ray contrast is injected, prior to injecting the medication, to confirm that the needle is in the right location in the epidural space. The most commonly injected medication consists of cortisone (steroid), and local anesthetic (freezing). PRP can also be injected into the epidural space and studies suggest there are advantages to PRP in many instances.
The goal of epidural injections is to reduce pain so that you can resume normal activities, work on lifestyle factors that contribute to back pain (i.e.physical inactivity, smoking and obesity) and start a back exercise program. Epidural cortisone injections themselves do not change the long-term outcome of the condition causing pain, but often the condition will go away over time as with a herniated disc and can improve with physical therapy and lifestyles changes. Epidurals are often used to treat an acute attack of back or leg pain. Epidural injections may also reduce the need for invasive procedures such as surgery.
Injections can be repeated, but are limited by the side effects of cortisone. Most physicians would recommend no more than 3-4 spine injections with cortisone a year and even that would not be recommended for long periods of time.
A procedure similar to an epidural, called a spinal nerve root block, can help confirm the origin spine nerve pain and direct future treatments such as surgery.
There is early evidence for PRP in treating chronic disc back pain and leg pains from pinched spinal nerves. This evidence suggests that the effects of PRP are longer lasting than cortisone, although not as quick in onset. The main advantages of PRP are likely in the avoidance of the side effects of cortisone, longer duration of action, and the potential for strengthening and healing of tissues of the spine. You can refer to our page on PRP for more information on PRP
What are the Risks
of Epidural Injections?
Serious risks include infection, nerve injury and bleeding around the spinal cord/nerves. These risks are all extremely rare. Those taking some blood thinner medications may need to stop them before epidurals as they can increase the chance of serious bleeding.
More common than the risks just described, but also relatively rare, is a spinal headache, which is caused by puncturing the dura (which is beyond the epidural space) and the leakage of spinal fluid into the epidural space. This headache can last in some cases up to a few weeks and may require an additional spine injection to rectify.
Other risks include temporary increase in pain, and allergic reaction to the medications injected.
Steroids can cause temporary increases in blood sugars in those with diabetes. Repeated injections of cortisone can contribute to osteoporosis and are known to cause adrenal gland suppression.
Overall, the most common side effects of epidurals are from the cortisone itself.
There are 3 main types of epidurals:
Interlaminar (medial):The approach is just at or just lateral to the midline between the lamina of adjacent vertebrae. This approach is the most common for disc pain and spinal stenosis.
Transforaminal (lateral): this approach is most common when targeting specific nerves that are being pinched in the spine.
Caudal (tailbone): The needle is placed in the sacral hiatus above the tailbone and from there will flow upward to surround the lower spinal nerves.