title: Does lumbar spinal degeneration begin with the anterior structures? A study of the observed epidemiology in a community-based population.
abstract: BACKGROUND
  Prior studies that have concluded that disk degeneration uniformly precedes facet degeneration have been based on convenience samples of individuals with low back pain. We conducted a study to examine whether the view that spinal degeneration begins with the anterior spinal structures is supported by epidemiologic observations of degeneration in a community-based population.
  
  
  METHODS
  361 participants from the Framingham Heart Study were included in this study. The prevalences of anterior vertebral structure degeneration (disk height loss) and posterior vertebral structure degeneration (facet joint osteoarthritis) were characterized by CT imaging. The cohort was divided into the structural subgroups of participants with 1) no degeneration, 2) isolated anterior degeneration (without posterior degeneration), 3) combined anterior and posterior degeneration, and 4) isolated posterior degeneration (without anterior structure degeneration). We determined the prevalence of each degeneration pattern by age group < 45, 45-54, 55-64, ≥65. In multivariate analyses we examined the association between disk height loss and the response variable of facet joint osteoarthritis, while adjusting for age, sex, BMI, and smoking.
  
  
  RESULTS
  As the prevalence of the no degeneration and isolated anterior degeneration patterns decreased with increasing age group, the prevalence of the combined anterior/posterior degeneration pattern increased. 22% of individuals demonstrated isolated posterior degeneration, without an increase in prevalence by age group. Isolated posterior degeneration was most common at the L5-S1 and L4-L5 spinal levels. In multivariate analyses, disk height loss was independently associated with facet joint osteoarthritis, as were increased age (years), female sex, and increased BMI (kg/m(2)), but not smoking.
  
  
  CONCLUSIONS
  The observed epidemiology of lumbar spinal degeneration in the community-based population is consistent with an ordered progression beginning in the anterior structures, for the majority of individuals. However, some individuals demonstrate atypical patterns of degeneration, beginning in the posterior joints. Increased age and BMI, and female sex may be related to the occurrence of isolated posterior degeneration in these individuals.
authors.affiliation: Division of PM&R, VA Boston Healthcare System, Boston, USA. pradeepsuri1@gmail.com
authors.forename: Pradeep
authors.initials: P
authors.lastname: Suri
authors.forename: Asako
authors.initials: A
authors.lastname: Miyakoshi
authors.forename: David J
authors.initials: DJ
authors.lastname: Hunter
authors.forename: Jeffrey G
authors.initials: JG
authors.lastname: Jarvik
authors.forename: James
authors.initials: J
authors.lastname: Rainville
authors.forename: Ali
authors.initials: A
authors.lastname: Guermazi
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Katz
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000000981:diagnostic imaging / Q000473:pathology*; D055959:Intervertebral Disc Degeneration / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D055013:Osteoarthritis, Spine / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology*; D015995:Prevalence; D012111:Residence Characteristics; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D021801:Zygapophyseal Joint / Q000473:pathology*