title: Early pattern of degenerative changes in individual components of intervertebral discs in stressed and nonstressed segments of lumbar spine: an in vivo magnetic resonance imaging study.
abstract: METHODS
  A retrospective imaging review.
  
  
  OBJECTIVE
  To assess differences in burden and pattern of disc degeneration in segments of lumbar spine with and without signs of increased mechanical stresses.
  
  
  BACKGROUND
  Young patients with magnetic resonance imaging signs of increased mechanical stress in pedicles or pars interarticularis provide an excellent in vivo model to study early effects of mechanical stresses on lumbar intervertebral discs without the confounding effects of genetics or environmental factors. Detailed in vivo evaluation for early degenerative changes in all individual disc components of stressed intervertebral discs has not been done.
  
  
  METHODS
  Using magnetic resonance imaging, 2 radiologists assessed intervertebral discs around 93 stressed lumbar spinal segments in 87 patients (55 males, 32 females; mean age, 15.3 ± 3.3 yr; range, 5-25 yr) as well as lumbar discs in nonstressed segments for signs of degeneration in annulus fibrosus, nucleus pulposus, and endplates. Differences between stressed, control, and loading-matched control discs were assessed using Wilcoxon signed rank sum test.
  
  
  RESULTS
  Burden of annular tears, radial tears, herniations, and nuclear degeneration was significantly higher in stressed discs (0.70 ± 0.34, 0.48 ± 0.39, 0.07 ± 0.19, and 0.17± 0.31, respectively) than control (0.29 ± 0.25, 0.09 ± 0.17, 0.01 ± 0.04, and 0.02 ± 0.08, respectively) or loading-matched control discs (0.44 ± 0.47, 0.16 ± 0.36, 0.01 ± 0.04, and 0.01 ± 0.11, respectively) (P < 0.01 for all). Stressed segments did not show any significant increase in endplate degeneration.
  
  
  CONCLUSIONS
  Intervertebral discs in stressed spinal segments show an increased burden of disc degeneration involving annulus fibrosus and nucleus pulposus, but not the endplates.
  
  
  METHODS
  N/A.
authors: *Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO; †Department of Radiology, Barnes-Jewish Hospital South, St. Louis, MO; and ‡Department of Radiology, St. Louis Children's Hospital, St. Louis MO.
authors: Aseem
authors: A
authors: Sharma
authors: Samantha
authors: S
authors: Lancaster
authors: Swapnil
authors: S
authors: Bagade
authors: Charles
authors: C
authors: Hildebolt
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000473:pathology / Q000503:physiopathology; D055959:Intervertebral Disc Degeneration / Q000473:pathology* / Q000503:physiopathology*; D008159:Lumbar Vertebrae / Q000473:pathology* / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D012189:Retrospective Studies; D013314:Stress, Mechanical; D055815:Young Adult