Study Results Suggest Discography Has Outlived Its Utility
The never ending problem facing physicians responsible for the care of back pain patients is the identification of the source of discomfort. The spine consists of a number of tissues with nerves that transmit pain. Theoretically, the intervertebral disc should be a source of pain, but this structure only receives sensory input at its outer margins and is a less likely source of chronic low back pain. Despite these anatomic facts, radiographic techniques have been developed to identify painful disc levels through the use of provocative discography.
Provocative discography is an invasive diagnostic procedure involving a fluroscopically-directed injection of contrast dye with pressurization into an intervertebral disc. If back pain is generated, an anesthetic is injected to relieve pain. A positive test is considered the generation and resolution of pain with the injection sequence. Individuals, who have had positive discograms, have undergone spinal fusion operations with varying degrees of pain resolution.
The questions that surround the use of discography are the following:
- Does discography accurately identify painful disc levels?
- Does discography cause disc degeneration?
- Do discography patients undergo more procedures and medical visits?
Studies have been completed that directly address these questions. In regard to the ability of discograms to identify levels of low back pain, positive discography patients were matched against individuals with painful unstable spines (spondylolisthesis). Each group underwent a spinal fusion at the identified painful level. In the spondylolisthesis group, 29 of 32 (91%) had a good outcome while only 13 of 30 (43%) had a good outcome. Positive discography was no better than chance at identifying individuals with painful disc levels that would benefit from surgical stabilization.
Discography causes disc degeneration. In another study individuals without serious back pain underwent discography at L3 to L5 and were compared to a matched group simultaneously who underwent evaluation of their lumbar using MRI. These patients have now been evaluated for 10 year and the following observations have been reported.
- 35% of the discography discs had greater progression of degenerative findings than 14% of the MRI evaluated discs.
- Disc herniation was more common on the side of the discography annular puncture along with greater loss of disc height.
- Individuals who undergo discography utilize more medical care and have greater amounts of disability. Over a ten year observation period, 16 surgeries occurred in 57 discography patients compared to only 4 in 53 patients evaluated with MRI.
These results suggest that discography has outlived its utility if it had any at all. This procedure is not predictive of painful spine levels that are improved with surgical intervention. In addition, the procedure itself has morbidity that results in greater patient pain and suffering.
David Borenstein, MD Executive Editor theSpineCommunity
Carragee EJ et al. A gold standard evaluation of the “discogenic pain” diagnosis as determined by provocative discography. Spine 2006;31:2115-21123
Carragee EJ et al. 2009 ISSLS Prize Winner: Does discography cause accelerated progression of degenerative changes in the lumbar spine: a ten-year matched cohort study. Spine 2009;34:2338-2345\
Cuellar JM, et al. Does provocative discography cause clinically important injury to the lumbar intervertebral disc? A 10-year matched control study. Spine J.2016;16:273-80