title: Prevalence and pattern of lumbar magnetic resonance imaging changes in a population study of one thousand forty-three individuals.
abstract: METHODS
  A cross-sectional population study of magnetic resonance imaging (MRI) changes. OBJECTIVE.: To examine the pattern and prevalence of lumbar spine MRI changes within a southern Chinese population and their relationship with back pain.
  
  
  BACKGROUND
  Previous studies on MRI changes and back pain have used populations of asymptomatic individuals or patients presenting with back pain and sciatica. Thus, the prevalence and pattern of intervertebral disc degeneration within the population is not known.
  
  
  METHODS
  Lumbar spine MRIs were obtained in 1043 volunteers between 18 to 55 years of age. MRI changes including disc degeneration, herniation, anular tears (HIZ), and Schmorl's nodes were noted by 2 independent observers. Differences were settled by consensus. Disc degeneration was graded using Schneiderman's classification, and a total score (DDD score) was calculated by the summation of the Schneiderman's score for each lumbar level. A K-mean clustering program was used to group individuals into different patterns of degeneration.
  
  
  RESULTS
  Forty percent of individuals under 30 years of age had lumbar intervertebral disc degeneration (LDD), the prevalence of LDD increasing progressively to over 90% by 50 to 55 years of age. There was a positive correlation between the DDD score and low back pain. L5-S1 and L4-L5 were the most commonly affected levels. Apart from the usual patterns of degeneration, some uncommon patterns of degeneration were identified, comprising of subjects with skip level lesions (intervening normal levels) and isolated upper or mid lumbar degeneration.
  
  
  CONCLUSIONS
  LDD is common, and its incidence increases with age. In a population setting, there is a significant association of LDD on MRI with back pain.
authors.affiliation: Department of Orthopaedics and Traumatology, University of Hong Kong, Hong Kong, China. cheungmc@hku.hk
authors.forename: Kenneth M C
authors.initials: KM
authors.lastname: Cheung
authors.forename: Jaro
authors.initials: J
authors.lastname: Karppinen
authors.forename: Danny
authors.initials: D
authors.lastname: Chan
authors.forename: Daniel W H
authors.initials: DW
authors.lastname: Ho
authors.forename: You-Qiang
authors.initials: YQ
authors.lastname: Song
authors.forename: Pak
authors.initials: P
authors.lastname: Sham
authors.forename: Kathryn S E
authors.initials: KS
authors.lastname: Cheah
authors.forename: John C Y
authors.initials: JC
authors.lastname: Leong
authors.forename: Keith D K
authors.initials: KD
authors.lastname: Luk
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001416:Back Pain / Q000175:diagnosis / Q000453:epidemiology; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D006801:Humans; D015994:Incidence; D007403:Intervertebral Disc / Q000473:pathology*; D007405:Intervertebral Disc Displacement / Q000175:diagnosis* / Q000453:epidemiology; D008159:Lumbar Vertebrae / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D015995:Prevalence; D012585:Sciatica / Q000175:diagnosis / Q000453:epidemiology; D055815:Young Adult