Systematic review of lumbar discography as a diagnostic test for chronic low back pain.

BACKGROUND The intervertebral disc has been implicated as an etiology of chronic lumbar spine pain based on clinical, basic science, and epidemiological research. However, there is lack of consensus regarding the diagnosis and treatment of intervertebral disc disorders. Based on controlled evaluations, the lumbar intervertebral discs have been shown to be sources of chronic back pain without disc herniation in 26% to 39%. Lumbar provocation discography, which includes disc stimulation and morphological evaluation, is often used to distinguish a painful disc from other potential sources of pain. Despite the extensive literature, controversy continues about provocation lumbar discography. STUDY DESIGN A systematic review of the lumbar provocation discography literature. OBJECTIVES To systematically assess the diagnostic accuracy of lumbar discography. METHODS A systematic review of the literature was performed to assess the diagnostic accuracy of lumbar discography with respect to chronic low back pain. Study inclusion/exclusion criteria were based on International Association for the Study of Pain (IASP) standards with pain provocation and determination of controlled discs. Selected studies were then subjected to a rating instrument for diagnostic accuracy studies. Specific data were then culled from these studies and tabulated. Quality of evidence was assessed using modified Agency for Healthcare Research and Quality (AHRQ) diagnostic accuracy evaluation. Studies meeting methodologic quality criteria scores of 50 or higher were included in the assessment of the level of evidence. Qualitative analysis was conducted using 5 levels of evidence, ranging from Level I to III, with 3 subcategories in Level II. The rating scheme was modified to evaluate the diagnostic accuracy. RESULTS Based on a modified U.S. Preventive Services Task Force (USPSTF) level of evidence criteria, this systematic review indicates the strength of evidence as Level II-2 for the diagnostic accuracy of lumbar provocation discography utilizing IASP criteria. LIMITATIONS Limitations include a paucity of literature, poor methodologic quality, and very few studies performed utilizing IASP criteria. CONCLUSION Based on the current systematic review, lumbar provocation discography performed according to the IASP criteria with control disc (s) with minimum pain intensity of 7 of 10, or at least 70% reproduction of worst pain (i.e. worst spontaneous pain of 7 = 7 x 70% = 5) may be a useful tool for evaluating chronic lumbar discogenic pain. Discography is an important imaging and pain evaluation tool in identifying a subset of patients with chronic low back pain secondary to intervertebral disc disorders.