title: MRI evaluation of lumbar endplate and facet erosion in rheumatoid arthritis.
abstract: METHODS
  A cross-sectional study.
  
  
  OBJECTIVE
  This study was aimed to quantify the extent of lumbar endplate and facet joint erosion in patients with rheumatoid arthritis (RA) using magnetic resonance imaging, to calculate the prevalence of erosion, and sought correlated factors.
  
  
  BACKGROUND
  Few studies have examined the lumbar spine in RA, especially the relationship between endplate and facet joint erosions and lumbar lesions induced by RA.
  
  
  METHODS
  A total of 201 patients with RA were enrolled. Lumbar endplate and facet joint erosion were defined as irregularities and low-intensity change on magnetic resonance imaging, and graded utilizing the Rheumatoid Arthritis Magnetic Resonance Imaging Score. Lumbar lesions were defined as scoliosis, spondylolisthesis, and vertebral fracture on plain x-ray. Multivariable logistic regression analysis was used to seek correlations between the erosion and spinal level, RA-related factors and x-ray findings.
  
  
  RESULTS
  Lumbar endplate and facet erosion were detected in 70.6% and 76.6% of individuals, respectively, and at 33.8% and 38.7% of lumbar intervertebral levels, respectively. The severity of erosion in individual patients correlated with lumbar lesions. Endplate and facet erosion at each level correlated with high disease activity, and were most common at mid-lumbar and lower-lumbar levels. Strong correlations were observed between endplate erosion and adjacent vertebral body fracture or disk degeneration, and between facet erosion and spondylolisthesis.
  
  
  CONCLUSIONS
  Lumbar endplate and facet erosion are common in RA, and are observed more frequently at mid-low levels and when RA is poorly controlled. This pattern of erosion may play a crucial role in the generation of lumbar lesions in RA.
authors.affiliation: Departments of *Orthopaedic Surgery †Rheumatology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Yamada
authors.forename: Akinobu
authors.initials: A
authors.lastname: Suzuki
authors.forename: Shinji
authors.initials: S
authors.lastname: Takahashi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yasuda
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tada
authors.forename: Yuko
authors.initials: Y
authors.lastname: Sugioka
authors.forename: Tadashi
authors.initials: T
authors.lastname: Okano
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Koike
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nakamura
mesh_terms: D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D015588:Observer Variation; D011859:Radiography; D021801:Zygapophyseal Joint / Q000000981:diagnostic imaging / Q000473:pathology*