Does provocative discography cause clinically important injury to the lumbar intervertebral disc? A 10-year matched cohort study.

BACKGROUND CONTEXT: Provocative discography, an invasive diagnostic procedure involving disc puncture with pressurization, is a test for presumptive discogenic pain in the lumbar spine. The clinical validity of this test is unproven. Data from multiple animal studies confirm that disc puncture causes early disc degeneration. A recent study identified radiographic disc degeneration on magnetic resonance imaging (MRI) performed 10 years later in human subjects exposed to provocative discography. The clinical effect of this disc degeneration after provocative discography is unknown.

PURPOSE: The aim of this study was to investigate the clinical effects of lumbar provocative discography on patients subjected to this evaluation method.

STUDY DESIGN/SETTING: A prospective, 10-year matched cohort study.

PATIENT SAMPLE: Subjects (n=75) without current low back pain (LBP) problems were recruited to participate in a study of provocative discography at the L3-S1 discs. A closely matched control cohort was simultaneously recruited to undergo a similar evaluation except for discography injections.

OUTCOME MEASURES: The primary outcome variables were diagnostic imaging events and lumbar disc surgery events. The secondary outcome variables were serious LBP events, disability events, and medical visits.

METHODS: The discography subjects and control subjects were followed by serial protocol evaluations at 1, 2, 5, and 10 years after enrollment. The lumbar disc surgery events and diagnostic imaging (computed tomography (CT) or MRI) events were recorded. In addition, the interval and cumulative lumbar spine events were recorded.

RESULTS: Of the 150 subjects enrolled, 71 discography subjects and 72 control subjects completed the baseline evaluation. At 10-year follow-up, 57 discography and 53 control subjects completed all interval surveillance evaluations. There were 16 lumbar surgeries in the discography group, compared with four in the control group. Medical visits, CT/MRI examinations, work loss, and prolonged back pain episodes were all more frequent in the discography group compared with control subjects.

CONCLUSION: The disc puncture and pressurized injection performed during provocative discography can increase the risk of clinical disc problems in exposed patients.