Prevalence and Characteristics of Discogenic Pain in Tertiary Practice: 223 Consecutive Cases Utilizing Lumbar Discography.

BACKGROUND: Between 26% and 42% of chronic low back pain is attributed to internal disc disruption of lumbar intervertebral discs. These prevalence estimates and data characterizing discogenic pain originate largely from research at elite practices, conducted 20 years ago. With few studies since, their concordance with rates in community practice has rarely been addressed.

OBJECTIVE: To assess the prevalence and key features of discogenic pain within community-based tertiary practice, and to evaluate the accuracy and clinical utility of discography.

DESIGN: This prospective, three-year study of 223 consecutive cases of chronic low back pain used image-guided lumbar discography to identify symptomatic and flanking asymptomatic discs. A subset of patients (n = 195) had previously undergone posterior column blocks to investigate spinal facet and/or sacroiliac joints as contributing pain sources.

RESULTS: A total of 644 discs were tested without infection or complication. Positive discograms were recorded in 74% of patients, with 22.9% negative and 3.1% assessed as indeterminate. Among patients receiving both discography and diagnostic blocks, 63% had proven discogenic pain, 18% had pain of mixed etiology and 14% remained undiagnosed. Taking into account all low back pain cases during this study (n = 756), discogenic pain prevalence was 21.8% (95% CI: 17-26%).

CONCLUSION: The prevalence of discogenic pain in this community practice is below the range, but within confidence intervals, previously reported. Prevalence is considerably elevated, however, among well-selected patients and discography enabled a firm diagnosis in most such cases. These findings are broadly in keeping with those reached in key publications and support the clinical utility of discography.