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.
Who would need a lumbar discography?
Lumbar discography is considered for patients who, despite extensive conservative treatment, have disabling low back pain, groin pain, hip pain, and/or leg pain. When a variety of spinal diagnostic procedures have failed to elucidate the primary pain generator, these individuals may benefit from lumbar discography especially if spinal surgery is contemplated.
The lumbar discogram is designed to induce pain in a sensitive disc. A spinal fusion procedure that is designed to obliterate an internally disrupted, painful disc (pain generator) would not be the procedure of choice if pressurisation of the disc didn’t reproduce the patient’s clinical discomfort. The surgeon needs to be absolutely sure that the level or levels being fused are responsible for the patient’s pain.
If the fused levels were not initially painful, surgery will not help, and the patient will be left with a fused spine and probably still be in pain. Since a fusion procedure carries a risk factor and healing time, the more information that can be obtained prior to surgery the better.
The lumbar discography is done under sedation as this allows the accurate placement of the needle into the disc without too much distress. Once the needle is in place you are woken up and asked whether we are able to reproduce your usual pain by distending the disc with contrast dye. This procedure is done with antibiotic cover to reduce risk of infection. You should fast for six hours before the procedure.
You are placed on a table and a mobile x-ray unit is used to guide the accurate placement of the needle into the disc. Your back is then marked with an ink pen over the disc spaces that will ultimately be examined, after which your back is thoroughly cleansed and sterile drapes are applied.
Administration of local anaesthesia
The goal is to anaesthetise a core of tissue that extends from your skin to the disc surface. When these tissues are numbed, a guide needle is directed towards the disc and will just touch the outer margins of the disc.
Through this guide needle, a much smaller disc needle is advanced towards and eventually inserted into the centre of the disc. This process should not be painful, but a little pain is sometimes felt.
The procedure usually takes less than an hour to perform. You’ll have soreness from the needle punctures that lasts several days. You may use Diclofenac, Codydramol, Tramadol or ibuprofen painkillers and apply an ice pack for a few minutes to ease the soreness.
Pressurising the discs - the diagnostic part of the procedure
After all of the needles are placed, the discs are "pressurised" one at a time. Pressurisation consists of injecting small amounts of a sterile liquid (usually contrast material [x-ray dye]) into the centre of the disc.
This is the most important part of the study and you must concentrate on what you are feeling. There are essentially three choices:
- You feel nothing
- You feel pressure
- You feel pain
If you feel pain from the injection, the pain is either:
- Familiar pain, which translates into "ouch, that’s my pain!"
- Unfamiliar pain, which belongs to someone else or translates into "ouch, I’ve never felt that pain before."
After each level is pressurised, pictures are taken with the x-ray and the needles are removed.
The procedure usually takes less than an hour to perform. You’ll have soreness from the needle punctures that lasts several days. You may use painkillers and apply an ice pack for a few minutes to ease the soreness.
Possible risks and complications
As with any invasive test, there are associated risks and possible complications with a lumbar discogram:
- The most feared complication is a disc space infection, which can be very difficult to treat. Fortunately, by using very strict sterile techniques and antibiotic cover, this is a very uncommon complication
- There are extremely remote possibilities of nerve root injury
- Spinal headache is also a remote risk
In summary, a discogram is a study designed to determine if an intervertebral disc is a pain generator. The initial needle placement need not be painful. If pressurisation of a disc causes a familiar pain, then surgical obliteration (fusion) of the pain generator(s) may afford significant pain relief.
Return to treatments and operations.