A discogram — more precisely, provocative discography — is a diagnostic test. Contrast dye is injected under pressure into one or more spinal discs. The patient stays awake and reports what they feel. It is not a treatment. It is not an imaging study in the usual sense either. The point is to see whether pressure in one disc brings on the patient’s own familiar pain, and whether the discs next to it do not.
Why the test exists
A discogram is almost never ordered to find out if a disc looks bad. An MRI already answers that. Degenerated (broken-down) discs are very common in people with no back pain at all. A systematic review of imaging in 3,110 people without symptoms found disc degeneration in 37% of 20-year-olds and 96% of 80-year-olds. Annular fissures (cracks in the disc’s outer wall) showed up in 19% to 29%, depending on age.1 Scan enough pain-free people and you will find plenty of ugly discs.
So imaging alone cannot tell you which disc, if any, is causing a person’s pain. Provocative discography adds a step that tests the disc itself. Stress the disc directly and see whether the patient knows the feeling as their own pain. In the medical papers this is called concordant pain. A disc that hurts in a strange, new way is not concordant. Under most protocols it does not count as positive.
How the procedure is done
The patient lies face down. The skin and deeper tissues are numbed. Using live X-ray (fluoroscopy), the doctor guides a thin needle in from the back and side. It goes into the center of the target disc, the nucleus pulposus. A second needle goes into at least one nearby disc to serve as a control. Contrast is then injected slowly. A manometer (a pressure gauge) often measures the pressure inside the disc.
Three things are recorded at each level:
- Pain intensity — usually on a 0–10 scale.
- Concordance — whether the pain is the patient’s usual pain, a different pain, or no pain at all.
- Pressure and volume — how much pressure above opening pressure set off the pain, and how much contrast the disc took.
The patient must be awake and able to answer questions. No sedation is used, because sedation would dull those answers and destroy the only thing the test measures. A CT scan afterward maps annular fissures more precisely than fluoroscopy alone.
Everything on this page is about lumbar (low back) discography. That is where all of the evidence below comes from. Doctors also do cervical and thoracic discography, but none of these studies cover them.
Recovery
Recovery is short. Expect soreness at the needle sites and a flare of the usual back pain for a day or two. With no sedation, most patients drive themselves home and return to normal activity within two to four hours. Arrange a ride only if a leg feels temporarily weak or numb, and only until that wears off. The thing to watch for afterward is infection. Report a new fever, or back pain that gets worse instead of settling, right away. Do not wait it out. The numbers on that risk are further down.
What counts as a positive result
There is no single definition that everyone accepts. That is part of the problem. Stricter pressure-controlled protocols require all of the following: pain at or above a set level (often 6/10 or 7/10), that the patient calls familiar, brought on at low pressure (for example, at or below 50 psi above opening pressure), with a limited injected volume, and at least one adjacent control disc that is not painful.2
The control disc is not a formality. Without a neighbor that tests negative, a painful injection cannot tell apart two things. One is a true pain source. The other is a patient who hurts whenever anything in the spine is put under pressure.
The controversy, stated plainly
Provocative discography has been disputed for three decades, and the criticism has real weight. The most influential work comes from Eugene Carragee and colleagues at Stanford. They ran controlled experiments, injecting discs in people who were not there for back pain.
One small but pointed study used eight patients with no history of low back pain. Each had bone taken from the back of the hip (posterior iliac crest bone graft harvesting) for an unrelated surgery. Then they had lumbar discography. Half met the usual criteria for a positive discogram. They reported pain they judged similar or identical to the soreness at the graft site.3 The sample was tiny. The meaning was not. Patients may be unable to reliably tell spine pain from pain coming from somewhere else during the test.
A second study looked at 20 volunteers without symptoms who had done well after a single-level discectomy (surgery to remove part of a disc). Forty percent had positive injections of the previously operated disc. In patients who still had symptoms after discectomy, but normal psychological testing, the rate was 43%. That difference did not reach statistical significance. But that group had only seven people, so on its own it settles little. The clearer signal in the same study was this. Patients with abnormal psychological test results had much higher positive rates than either group.4
A third study tested a claim. Would restricting positives to low-pressure injections get rid of false positives? Among 69 volunteers without clinically significant low back pain, 25% had at least one low-pressure positive disc. That is about the same as the 27% rate seen in patients being tested for chronic low back pain. Positive injections tracked with torn outer disc walls, chronic pain elsewhere, and abnormal psychological test results.5
Then came the outcome question. Thirty-two patients with a positive single-level low-pressure discogram went to fusion. They were compared with a matched cohort with unstable spondylolisthesis (a slipped vertebra), a problem nobody disputes. By a highly effective success threshold, 72% of the spondylolisthesis group succeeded. The group with presumed disc pain succeeded 27% of the time. After adjusting for surgical harm and dropout, the best-case positive predictive value of discography came to 50% to 60%.6
That is a thin margin on which to build a fusion decision. Other work points the same way, with caveats. In one retrospective cohort, the choice to fuse had already been made on other grounds. There, the discogram results of the discs adjacent to the fusion had no effect on how patients did. A systematic review in the same report found that no common prognostic test for lumbar fusion is accurate enough.7
The case for the test, honestly stated
The defense is not that the critics have their numbers wrong. It is that false-positive rates depend heavily on technique and on who is being tested. Under strict pressure-controlled, gauge-measured criteria, the test sorts discs better in at least some groups. In one prospective study, 58.2% of discs in volunteers without symptoms had Grade 3 annular tears. These discs looked clearly abnormal. Yet every one met negative response criteria once strict pressure and pain thresholds were used.2 That is exactly the sorting the test is supposed to do.
The counterweight is the low-pressure study above. A tighter pressure limit did not get rid of false positives in volunteers who had chronic pain elsewhere or abnormal psychological test results.5 Both findings can be true at once. Strict criteria appear to help most in people who are otherwise well. They help least in the patients most likely to be sent for the test in the first place.
A 2013 systematic review of the accuracy research graded the overall quality of evidence as fair. It concluded discography may be useful when done to formal International Association for the Study of Pain criteria.8 That review appeared in Pain Physician, the journal of the American Society of Interventional Pain Physicians. Its first author founded both the society and the journal. That is worth knowing when you weigh it against the Stanford work. Fair is not strong. It is also not nothing.
So technique and the choice of patients carry almost all of the diagnostic weight. Picture a discogram done without manometry, without a control disc, or on a patient with widespread pain. It gives a number that looks like data and is not.
The risk that changed the conversation
Putting a needle into a disc is not harmless. In a prospective matched-cohort study, 75 people had discography at L3–S1 in 1997. 10 years later they were compared with matched controls who had the same MRI protocol but no injections. Punctured discs got worse on every measure. Disc degeneration (breakdown) grew in 35% of discography discs versus 14% of controls. There were 55 new disc herniations versus 22. More of them than expected fell on the side where the needle went in.9
A follow-up analysis of the same cohorts tracked real-life events instead of images. Over 10 years there were 16 lumbar surgeries in the discography group versus 4 in controls. The discography group also had more doctor visits, more CT and MRI scans, more missed work, and more long bouts of back pain.10 These were people with no serious back pain problem when they enrolled.
Discitis, an infection of the disc space, is rarer but more acute (sudden and serious). A systematic review plus a series of 200 patients in a row found a rate of 0.25% without preventive antibiotics.7 Low, but not trivial for a test that only diagnoses.
Who is a reasonable candidate
A discogram makes sense in a narrow situation. All of these must be true. The low back pain is persistent and axial (it stays in the spine). It has not responded to a real course of conservative care. Imaging shows one or two plausible levels. Other pain sources are already ruled out. And a specific surgery or procedure decision is waiting on the answer. Ordering it when the result would not change anything is a common misuse.
It is a poor choice when pain is widespread instead of in one spot. It is also a poor choice when the facet joints or the sacroiliac joint have not been checked, or when emotional distress is strong and untreated. It is also a poor choice when there is active infection, bleeding risk, or pregnancy. False positives cluster in exactly the patients who are hardest to sort out in the clinic.5
What happens with the result
Take a well-chosen patient with a concordant positive at one level and negative control discs. That result supports, but does not prove, that disc as the pain source. It may lead to fusion, disc replacement, or a targeted procedure inside the disc or in the epidural space. Where scar tissue and adhesions in the epidural space add to the pain, epiduroplasty (epidural lysis of adhesions) is sometimes the more proportionate next step than fusion.
A negative discogram is often the more useful outcome. It takes a level off the surgery list. It points the workup toward facet joints, the sacroiliac joint, or a central pain mechanism (pain driven by the nervous system itself).
If you are in the St. Louis area
Padda Institute, Center for Interventional Pain Management performs fluoroscopically guided diagnostic procedures at 4477 Woodson Rd, Suite 100, St. Louis, MO 63134 and 12174 Natural Bridge Rd, St. Louis, MO 63044. For preparation instructions and scheduling, see the discogram procedure page or call (314) 481-5000.
Frequently asked questions
Is a discogram painful?
Yes, by design. The test only works if pressure in the disc brings back the pain. Local anesthetic numbs the needle path, but the pain itself is the measurement. If that is not acceptable to you, ask about other options such as diagnostic medial branch blocks, which work by relieving pain instead of causing it.
Why can’t an MRI tell my doctor which disc hurts?
Because disc degeneration (breakdown) is nearly universal with age and matches symptoms poorly. An MRI shows structure, not pain signals. See why your scan may not match your pain and what MRI, fluoroscopy, and ultrasound each actually measure.
What is internal disc disruption?
It means cracks and breakdown inside a disc whose outer shape still looks fine. It is the classic case of real axial (spine-centered) back pain with a reassuring MRI. Provocative discography was designed to find this condition. Our article covers it: internal disc disruption with a normal MRI.
Does a positive discogram mean I need fusion surgery?
No. It is one input among several. Its published positive predictive value for surgical success (how often a positive result predicts a good surgery outcome) is far from convincing. Reviews of chronic low back pain research also report that intensive exercise and cognitive behavioral programs get results similar to fusion, with fewer complications. So a positive result is a reason for a careful talk, not an automatic operation.7 See the data on unnecessary back surgeries before committing to an operation.
Can a discogram damage my disc?
The 10-year matched-cohort evidence says a needle puncture speeds up disc degeneration (breakdown). It also raises the rate of new herniations and later surgery compared with controls who had no puncture. That is the main reason to save the test for cases where the answer changes the plan. If you have already had spine surgery and still hurt, see why leg pain persists after back surgery and failed back surgery syndrome.
What should I ask before agreeing to a discogram?
Ask three things. What decision hangs on the result? Will a control disc and manometry be used? What happens if the test is negative? If no answer changes the plan, you do not need the test. See what to expect at a first pain appointment and choosing between an orthopedic surgeon, neurosurgeon, or pain physician.
Sources
- Brinjikji W, Luetmer PH, Comstock B, et al. Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. AJNR Am J Neuroradiol. 2015;36(4):811-816. PMID 25430861
- Derby R, Kim BJ, Lee SH, Chen Y, Seo KS, Aprill C. Comparison of discographic findings in asymptomatic subject discs and the negative discs of chronic LBP patients: can discography distinguish asymptomatic discs among morphologically abnormal discs? Spine J. 2005;5(4):389-394. PMID 15996608
- Carragee EJ, Tanner CM, Yang B, Brito JL, Truong T. False-positive findings on lumbar discography. Reliability of subjective concordance assessment during provocative disc injection. Spine (Phila Pa 1976). 1999;24(23):2542-2547. PMID 10626318
- Carragee EJ, Chen Y, Tanner CM, et al. Provocative discography in patients after limited lumbar discectomy: a controlled, randomized study of pain response in symptomatic and asymptomatic subjects. Spine (Phila Pa 1976). 2000;25(23):3065-3071. PMID 11145818
- Carragee EJ, Alamin TF, Carragee JM. Low-pressure positive discography in subjects asymptomatic of significant low back pain illness. Spine (Phila Pa 1976). 2006;31(5):505-509. PMID 16508542
- Carragee EJ, Lincoln T, Parmar VS, Alamin T. A gold standard evaluation of the “discogenic pain” diagnosis as determined by provocative discography. Spine (Phila Pa 1976). 2006;31(18):2115-2123. PMID 16915099
- Willems P. Decision making in surgical treatment of chronic low back pain: the performance of prognostic tests to select patients for lumbar spinal fusion. Acta Orthop Suppl. 2013;84(349):1-35. PMID 23427903
- Manchikanti L, Benyamin RM, Singh V, et al. An update of the systematic appraisal of the accuracy and utility of lumbar discography in chronic low back pain. Pain Physician. 2013;16(2 Suppl):SE55-SE95. PMID 23615887
- Carragee EJ, Don AS, Hurwitz EL, Cuellar JM, Carrino JA, Herzog R. 2009 ISSLS Prize Winner: Does discography cause accelerated progression of degeneration changes in the lumbar disc: a ten-year matched cohort study. Spine (Phila Pa 1976). 2009;34(21):2338-2345. PMID 19755936
- Cuellar JM, Stauff MP, Herzog RJ, Carrino JA, Baker GA, Carragee EJ. Does provocative discography cause clinically important injury to the lumbar intervertebral disc? A 10-year matched cohort study. Spine J. 2016;16(3):273-280. PMID 26133255
Dr. Gurpreet Singh Padda, MD, MBA, MHP
