Ability of discography to accurately diagnose discogenic back pain in question
The debate included arguments about whether discography is procedure-based or evidence-based.
AMSTERDAM — At SpineWeek 2012, here, two European spine experts — Jörg Franke, MD, PhD, and Philip J. Sell, BM, MSc, FRCS — debated a question many spine surgeons likely ask themselves today: Is discography still a viable solution for treating and diagnosing back pain?
There is no other alternative but provocative discography to identify discogenic pain, Franke of Klinikum Dortmund, in Dortmund, Germany, said.
“You should perform facet blocks and if they are positive, I would leave out the discography nowadays,” Franke said. “But in any other case of multilevel disease, I think with negative facet blocks, the alternative is still discography and it should still be alive.”
There are false positive and false negative results in 25% of patients undergoing discography, according to Franke, who cited research by Eugene Carragee, MD, of Stanford, Calif., USA, in making his argument. Despite this, other methods, including expert surgeons, MRI combined with the Pfirrmann classification and Modic signs, and facet degeneration assessments, do not work, Franke said.
He said 12 of 42 lumbar spine grading systems met reliability criteria for the lumbar spine and ten systems met the cervical spine criteria, according to Kettler and Wilke.
“Only 12 have reliabilities that meet the criteria, and that is not really good. So, maybe in this context, discography could be good compared to some of those other grading systems,” Franke said.
In a study Franke and colleagues conducted, six senior spine surgeons could not reliably grade facet joint and multifidus degeneration on MRI. They graded 288 facet joints at the lowest with 1.76 points, and at the highest with 2.7 points, on a 4-grade scale.
“This is not better than discography,” Franke said.
The success rate of discography in determining the origin of back pain is not good, since nearly 85% of back pain is still unexplained, Sell, of the University Hospitals of Leicester, United Kingdom, said in making his case.
“It is curious when you look at the data on discography pain, most of it is carried out on patients with chronic pain who have all sorts of centralization phenomena,” Sell said.
“When something becomes established in medical practice, it is difficult to extinguish that behavior,” he added. “Established practice in medicine often takes two or three generations to change. Use of discography became conveniently distorted into diagnosis methodology for discogenic pain, based probably around procedure-based rather than evidence-based medicine.”
Sell discussed a 2006 study by Carragee and colleagues that tested the gold-standard of discography and its effectiveness in detecting discogenic pain in which 32 patients with low back pain underwent low-pressure provocative discograms and spine fusion. Researchers compared their outcomes to controls with unstable spondylolisthesis. They found 30% success in the discogram group vs. 70% success in the spondylolisthesis control group, and discography had a 50% positive predictive value.
“If you remove the disc and obtain a solid fusion, which they did, they should be free of their pain,” Sell said. “So why did they fail, if they have done a successful operation on a successful diagnosis? I think discography is dead,” he said. – by Renee Blisard Buddle
Carragee EJ, Lincoln T, Parmar VS, Alamin T. A gold standard evaluation of the “discogenic pain” diagnosis as determined by provocative discography. Spine. 2006;31(18):2115-2123.
Franke J, Le Huec JC, Scheufler K, et al. Six senior spine surgeons are not able to reliably grade facet degeneration and multifidus degeneration! Paper #S13. Presented at EuroSpine 2011. October 19-21. Milan.
Kettler A, Wilke H-J. Review of existing grading systems for cervical or lumbar disc and facet joint degeneration. Eur Spine J. 2006;15:705-718. doi: 10.1007/s00586-005-0954-7.
Sell P, Franke J. Debate: Is discography dead in this decade? Presented at SpineWeek 2012. May 28-June 1. Amsterdam.
For more information:
Jörg Franke, MD, PhD, can be reached at Klinikzentrum Mitte, Beurhausstraße 40, 44137 Dortmund, Germany; email: email@example.com.
Phillip J. Sell, BM, MSc, FRCS, can be reached at Infirmary Square, Leicester LE1 5WW, United Kingdom; email: firstname.lastname@example.org.