title: Disc degeneration and chronic low back pain: an association which becomes nonsignificant when endplate changes and disc contour are taken into account.
abstract: BACKGROUND
  The objective of this study was to assess the association between severe disc degeneration (DD) and low back pain (LBP).
  
  
  METHODS
  A case-control study was conducted with 304 subjects, aged 35-50, recruited in routine clinical practice across six hospitals; 240 cases (chronic LBP patients with a median pain duration of 46 months) and 64 controls (asymptomatic subjects without any lifetime history of significant LBP). The following variables were assessed once, using previously validated methods: gender, age, body mass index (BMI), lifetime smoking exposure, degree of physical activity, severity of LBP, disability, and findings on magnetic resonance (MRI) (disc degeneration, Modic changes (MC), disc protrusion/hernia, annular tears, spinal stenosis, and spondylolisthesis). Radiologists who interpreted MRI were blinded to the subjects' characteristics. A multivariate logistic regression model assessed the association between severe DD and chronic LBP, adjusting for gender, age, BMI, physical activity, MC, disc protrusion/hernia, and spinal stenosis.
  
  
  RESULTS
  Severe DD at ≥1 level was found in 46.9 % of the controls and 65.8 % of the cases. Crude odds ratio (95 % CI), for suffering chronic LBP when having severe DD, was 2.06 (1.05; 4.06). After adjusting for "MC" and "disc protrusion/hernia," it was 1.81 (0.81; 4.05).
  
  
  CONCLUSIONS
  The association between severe DD and LBP ceases to be significant when adjusted for MC and disc protrusion/hernia. These results do not support that DD as a major cause of chronic LBP.
authors.affiliation: Departamento Científico, Fundación Kovacs, Paseo de Mallorca 36, 07012, Palma de Mallorca, Spain.
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Kovacs
authors.forename: Estanislao
authors.initials: E
authors.lastname: Arana
authors.forename: Ana
authors.initials: A
authors.lastname: Royuela
authors.forename: Ana
authors.initials: A
authors.lastname: Estremera
authors.forename: Guillermo
authors.initials: G
authors.lastname: Amengual
authors.forename: Beatriz
authors.initials: B
authors.lastname: Asenjo
authors.forename: Helena
authors.initials: H
authors.lastname: Sarasíbar
authors.forename: Isabel
authors.initials: I
authors.lastname: Galarraga
authors.forename: Ana
authors.initials: A
authors.lastname: Alonso
authors.forename: Carlos
authors.initials: C
authors.lastname: Casillas
authors.forename: Alfonso
authors.initials: A
authors.lastname: Muriel
authors.forename: Carmen
authors.initials: C
authors.lastname: Martínez
authors.forename: Víctor
authors.initials: V
authors.lastname: Abraira
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D017677:Age Distribution; D016022:Case-Control Studies; D015984:Causality; D059350:Chronic Pain / Q000175:diagnosis* / Q000453:epidemiology*; D015897:Comorbidity; D005260:Female; D006801:Humans; D015994:Incidence; D055959:Intervertebral Disc Degeneration / Q000175:diagnosis* / Q000453:epidemiology*; D017116:Low Back Pain / Q000175:diagnosis* / Q000453:epidemiology*; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D017678:Sex Distribution; D013030:Spain / Q000453:epidemiology