Lumbar Discography

Overview
Lumbar discography is an injection technique used to evaluate patients with back pain who have not responded to extensive conservative care regimens. The most common use of discography is for surgical planning prior to a lumbar fusion.

It should be understood that the discogram is less about the anatomy of the disc (what the disc looks like) and more about its physiology (determining if the disc is painful). It is well known that a really abnormal looking disc may not be painful and a minimally disrupted disc may be associated with severe pain. It is impossible to definitively diagnose a painful disc without performing a discogram. The lumbar MRI and CT Myelogram are very sensitive anatomic tests but are not very specific in defining actual pain generators. The discogram is designed to induce pain in a sensitive disc.

Technique
You will have an intravenous line started before the procedure. This is started just in case it becomes necessary to administer any medications during the procedure.

Once in the operating room, you will be asked to lay on your stomach. Next, your back is marked with a special marking pen that will not wash off with the preparatory scrub solution, but does come off with alcohol. A fluoroscopy (special X-ray machine) is used to identify and allow the discographer to mark your back corresponding to each vertebral level, of the discs, which he will ultimately examine. Your back will then be cleaned with a special solution. After this, a sterile drape is placed over your back. Your discographer will be wearing a sterile gown and gloves for this procedure—to minimize the risk of infection.

A local anesthetic, numbing medicine, is then placed in the skin, down to the vertebrae, just in the tissues through which the needle will be passing. The fluoroscope will help the discographer to direct the needle to the appropriate location. This location is the outer margin (annulus) of the disc. Through this needle, another needle is directed into the center of the disc (nucleus pulposus).

Once all the needles are in place, the discs will be “pressurized” by injecting a contrast material (X-ray dye). This will allow the center of the disc to be visualized on the fluoroscopy monitor. As this is done, three things can happen:

1. You feel nothing
2. You feel pressure
3. You feel pain

If you feel pain, it will fall into two categories

• Familiar — the same type of pain you usually have
• Unfamiliar — pain that you’ve never felt before

It is customary to pressurize a disc that is presumed to be normal and doesn’t cause you pain, as a control.
Once the discs in question have been evaluated, the needles are removed and a CT scan is performed to document the internal disc architecture. You are now finished.

What To Expect
The procedure may take nearly an hour to perform. You will have some soreness at the needle puncture sites, once the anesthetic wears off. This is normal and over-the-counter pain medications are all that is necessary for this type of pain. You can also apply an ice pack to help with pain.

Possible Risks and Complications
As with any procedure, there are some risks and complications.

1. Bleeding. Any time the skin is punctured, bleeding occurs. Blood thinners, such as coumadin, warfarin, heparin, LOVENOX, aspirin, ibuprofen, naproxen, and other nonsteroidal anti-inflammatory, can prolong bleeding. It may be necessary for you to stop these in preparation for this exam. Please check with your physician
2. Infection. With skin puncture, infections can occur because of bacteria. Your physician tries to minimize this by creating a sterile field through preparatory scrub and sterile drapes, gowns, and gloves.
3. Nerve root injury. This is a very remote risk that can occur from the needle, anesthetic, or intradiscal material. An "electric shock" feeling alerts the discographer to a nearby nerve and injection will not occur until the needle is repositioned. The chemical irritation of the anesthetics or intradiscal material may increase pain and their effects may last well beyond the procedure, but subside in time. No one can predict this time.
4. Spinal headache. This can occur if the layer of tissue holding the spinal fluid in place is punctured and loss of spinal fluid continues beyond 24hours. This can be fixed and the headache will resolve itself, usually without any intervention.

With proper technique and experience of the physician performing the exam, these risks are rare.