title: Phenotype profiling of Modic changes of the lumbar spine and its association with other MRI phenotypes: a large-scale population-based study.
abstract: BACKGROUND
  Modic changes (MC) are associated with low back pain. They represent vertebral endplate and adjacent vertebral marrow changes on magnetic resonance imaging (MRI), classified into three types. Because of small sample sizes, patient cohorts, and limited phenotype assessment, the morphology and involvement of MC and their association with other spinal phenotypes remain speculative.
  
  
  OBJECTIVE
  We addressed and proposed a phenotypic profiling of MC and their relationship with lumbar MRI phenotypes in a large-scale population-based study.
  
  
  METHODS
  A cross-sectional study of the Hong Kong Disc Degeneration Cohort.
  
  
  METHODS
  The study population consisted of 1,546 Southern Chinese volunteers.
  
  
  METHODS
  Topographical and morphological dimensions of MC, presence of disc degeneration (DD) and displacement, and Schmorl nodes were evaluated.
  
  
  METHODS
  Axial T1-weighted and sagittal T2-weighted MRIs (3T) were assessed.
  
  
  RESULTS
  Females were 62.4% (mean age, 49 years). The overall prevalence of MC was 21.9% (6.3% Type I and 15.5% Type II). Of all MC, 76% were located at the two lowest lumbar levels. Modic changes at the two lowest lumbar levels were more commonly located laterally (p<.001), less commonly anteriorly (p<.001), and were more extensive horizontally (p=.006) but not in vertical height compared with the upper levels. Type I MC were less common in the anterior part (p=.022), larger in size (height p=.004), and affected more likely the whole horizontal plane (p=.016) than Type II MC. Modic changes were associated with disc displacement, Schmorl nodes, and DD at the affected level (all p<.001), and the strength of association increased with the size of the lesion. Type I MC were associated more strongly with disc displacement (p=.008) and DD (p=.022) than Type II MC.
  
  
  CONCLUSIONS
  Our large-scale MRI study is the first to definitely note that MC were size- and type-dependently significantly associated with disc pathology and endplate abnormalities. Our phenotype profiling of MC may have clinical utility.
authors.affiliation: Department of Physical and Rehabilitation Medicine, Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Box 5000, 90014 Oulu, Finland.
authors.forename: Juhani H
authors.initials: JH
authors.lastname: Määttä
authors.affiliation: Department of Physical and Rehabilitation Medicine, Medical Research Center Oulu, University of Oulu and Oulu University Hospital, Box 5000, 90014 Oulu, Finland; Finnish Institute of Occupational Health, Health and Work Ability, Aapistie 1, 90220 Oulu, Finland.
authors.forename: Jaro I
authors.initials: JI
authors.lastname: Karppinen
authors.affiliation: Department of Orthopaedics and Traumatology, The University of Hong Kong, Professorial Block, 5th Floor, 102 Pokfulam Rd, Pokfulam, Hong Kong, SAR, China.
authors.forename: Keith D K
authors.initials: KD
authors.lastname: Luk
authors.affiliation: Department of Orthopaedics and Traumatology, The University of Hong Kong, Professorial Block, 5th Floor, 102 Pokfulam Rd, Pokfulam, Hong Kong, SAR, China. Electronic address: cheungmc@hku.hk.
authors.forename: Kenneth M C
authors.initials: KM
authors.lastname: Cheung
authors.affiliation: Department of Orthopaedics and Traumatology, The University of Hong Kong, Professorial Block, 5th Floor, 102 Pokfulam Rd, Pokfulam, Hong Kong, SAR, China. Electronic address: dsamartzis@msn.com.
authors.forename: Dino
authors.initials: D
authors.lastname: Samartzis
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000175:diagnosis*; D017116:Low Back Pain / Q000175:diagnosis*; D008161:Lumbosacral Region / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010641:Phenotype
keywords: Degeneration; Disc; Displacement; Endplate; Epidemiology; Magnetic resonance imaging; Modic changes; Phenotype; Schmorl nodes