title: Grade three disc degeneration is a critical stage for anterior spondylolisthesis in lumbar spine.
abstract: BACKGROUND
  Little is known about when and how progressive spondylolisthesis occurs. In this report segmental motion related to age and disc degeneration at L4/5 disc was investigated.
  
  
  METHODS
  637 patients with low back and/or leg pain underwent radiologic and MRI examinations simultaneously. Because 190 patients with conditions which might impede accurate measurement were excluded, 447 patients, comprising 268 men and 179 women, were included; age range, was 10-86 (mean: 53) years. Three radiologic parameters slip in neutral position (mm), sagittal translation (mm), and segmental angulation (degrees) were examined at the L4/5 segment. On T2-weighted MRI, severity of disc degeneration at L4/5 was classified by Pfirrmann's criteria, grade 1-5.
  
  
  RESULTS
  Results showed stage of disc degeneration that progressed according to aging with significant differences except for between grades 4 and 5. Amount of anterior slip was small among grades 1 to 3; however, it greatly increased between grades 3 and 4 and between grades 4 and 5, suggesting that grade 3 disc degeneration has a potential risk of future progression of anterior slip. This finding may also suggest that once significant slip occurs, it will progress to the final grade. Furthermore, the grade 3 degeneration group exhibited large amounts of motion in both angulation and translation, suggesting it was the most unstable group.
  
  
  CONCLUSIONS
  Our results with radiography and MRI indicate that grade 3 disc degeneration is a critical stage for the progression of lumbar spondylolisthesis at L4/5 segment.
authors.affiliation: Department of Rehabilitation Science, Kobe University Graduate School of Medicine in Hyogo Rehabilitation Center, 1070 Akebono-cho, Nishi-ku, Kobe, 651-2181, Japan. t_iguchi@hwc.or.jp
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Iguchi
authors.forename: Kotaro
authors.initials: K
authors.lastname: Nishida
authors.forename: Takuma
authors.initials: T
authors.lastname: Ozaki
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kitagawa
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Tsumura
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Kakutani
authors.forename: Takashi
authors.initials: T
authors.lastname: Yurube
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Kuroda
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D018450:Disease Progression; D005260:Female; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000150:complications* / Q000473:pathology*; D008161:Lumbosacral Region; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D013168:Spondylolisthesis / Q000209:etiology* / Q000473:pathology*; D055815:Young Adult