Diagnostic and Therapeutic Injections
Some of the diagnostic and/or therapeutic options available in the management of back pain, neck pain and other pain that originates from the spine are the use of epidural injections, facet injections and discography. These techniques have become very popular over the years due to their success in the conservative management of certain types of pain originating from the spine.
Epidural injections using corticosteroids have been found to be an effective treatment for people who are suffering from some types of low back pain, neck pain and radicular pain (pain in the upper or lower limb due to nerve inflammation in the spine). Lower limb radicular pain is also known as “sciatica”. Commonly, nerves that supply the neck/upper limbs or the low back/lower limbs are compressed/irritated inside the spine by a bulging or herniated disc, an arthritic bone spur, scar tissue or a combination of these factors. This causes the nerve to become irritated, inflamed and swollen; the more swollen it becomes, the more it pushes against local structures setting up an inflammatory reaction/vicious cycle. A corticosteroid is a powerful anti-inflammatory medication that acts to decrease the inflammation and swelling of this nerve, thereby breaking this vicious cycle of swelling/irritation and providing pain relief. The epidural space is an air pocket that surrounds the spinal cord and the spinal nerves. One commonly hears of the use of epidural anesthetic injections for pregnant women during labor and these are also used for surgical anesthesia during hernia, knee or leg surgery. This space can be accessed effectively by pain management specialists for depositing anti-inflammatory or other pain relieving medication around the spinal nerves thereby producing more effective and long lasting reprieve from some types of debilitating pain, such as back pain and neck pain. With the use of newly developed x-ray equipment we can enter the epidural space safely and more precisely from several directions and thus provide more effective coverage of the inflamed nerves. Using a translaminar or “down the middle” approach into a canal that has been narrowed by degeneration, inflammation and/or scarring allows medication to surround nerves and flow onto the deep ligaments and parts of the outer portions of the disc itself and can relieve some types of low back pain and neck pain. A transforaminal or “from the side” approach allows the medication to be injected through a tunnel that has been narrowed and relieves lower or upper limb pain that was produced from irritation of the large nerves that exit through these tunnels. A caudal or “through the tailbone” approach provides an opportunity for a specially made catheter to navigate through this space and allows for better visualization of swollen nerves, makes it possible to break-up scar tissue formation from previous spine surgery and permits more medication to be delivered to multiple levels of the spine at the same time.
Facet injections are effective for some cases of localized low back pain and neck pain. Small amounts of steroid and/or local anesthetic medication are injected into these small joints on either side of the spine. If these joints move more easily, allowing the spine to rotate without restriction and without pain, then the diagnosis is made and the injections, if steroid is used, proves therapeutic. If these results are only temporary then there is a more permanent way to relief using radio waves to burn and destroy the small nerve endings that innervate these joints. These techniques of using radio waves can provide long lasting relief from pain emanating from these facet joints.
Discography allows us to understand the role of the disc or “shock absorber” as a pain producer. Discography is performed via injecting a disc with small amounts of fluid and observing the results along with obtaining pictures of the discs (discograms). By measuring the pressure recorded in the disc at time of injection, how much fluid the disc can hold, and whether the injection allows a build up of pressure reproducing one’s pain are vital to diagnosing the disc as generating pain. This pain is produced via pressure on certain types of internal tears of the disc that will cause pain independent of the local structures surrounding the disc (such as the spinal nerves and facets discussed above). There can be tears inside the disc caused from degeneration or trauma. These tears can weaken the disc and lead to bulging or these tears can enlarge and allow for herniation of the internal contents of the disc to occur. Bulging discs and herniations of the inner disc materials put pressure on the surrounding nerves and in the case of the herniation, chemically irritate the surrounding nerves. Discs can eventually flatten with subsequent loss of liquid. People with disc pain can have surgery as an option but newer less invasive treatments can be offered such as using heat waves to repair tears, vaporizing disc material to reduce volume and ease the pressure on the bulging areas and injecting nutraceuticals, vitamins and herbal remedies to strengthen the disc material.
As one can see we are able to use spinal injections to both diagnose and treat pain of spinal origin through the use of carefully guided needle positioning, proper solutions and deposition of these solutions at precise locations. The use of injections (anesthetic and/or steroid) is also quite useful for many painful musculoskeletal conditions of the upper and lower limbs such as shoulder bursitis which is an inflammation of the small sac of fluid (bursa) that is located near the rotator cuff muscles. Other examples of conditions that respond to the above-described techniques include, but are not limited to, tennis elbow, knee arthritis, ankle sprain and heel spur syndrome/plantar fasciitis. Consider contacting your Orthopaedic medicine specialist for non-operative treatment for these conditions.
- Waldman, S. D., Atlas of Interventional Pain Management, WB Saunders Company, 1998 ( 2nd edition due at the end of 2003)
- American Society of Interventional Pain Physicians (ASIPP)
- International Spinal Injection Society (ISIS)