Brinjikji et al. Systematic literature review of imaging features of spinal degeneration in asymptomatic populations¶
One-paragraph summary¶
The authors synthesized 33 English-language CT/MRI studies containing 3,110 asymptomatic people and modeled prevalence by decade from age 20 to 80. Estimated disc degeneration rose from 37% at age 20 to 96% at age 80; bulge from 30% to 84%; protrusion from 29% to 43%; and annular fissure from 19% to 29% (PMID 25430861). The study does not show that all degeneration is harmless; it quantifies the high age-dependent base rate against which individual imaging must be interpreted.
Key findings¶
- 33 studies and 3,110 asymptomatic individuals.
- Disc degeneration: 37% at 20; 96% at 80.
- Disc bulge: 30% at 20; 84% at 80.
- Disc protrusion: 29% at 20; 43% at 80.
- Annular fissure: 19% at 20; 29% at 80.
- Generalized linear mixed-effects modeling accounted for clustering by study.
Limitations¶
- Heterogeneous imaging techniques and feature definitions.
- English-language published studies through April 2014.
- “Asymptomatic” definitions and recruitment varied.
- Decade estimates are modeled cross-sectional prevalence, not longitudinal trajectories.
- The study estimates specificity constraints; it does not estimate individual causality.
Why it matters¶
This paper is the quantitative safeguard against equating a degenerative MRI with a pain diagnosis. It changed how radiology findings are communicated and how DDD cohorts should be interpreted.
Cited by wiki pages¶
- Overview
- Nomenclature and diagnostic validity
- Epidemiology and natural history
- Imaging and grading
- Discogenic pain and differential
- Biomarkers