title: The clinical importance of lumbosacral transitional vertebra in patients with adolescent idiopathic scoliosis.
abstract: METHODS
  Retrospective review of radiographs.
  
  
  OBJECTIVE
  The objective of this study was to (1) determine the prevalence of lumbosacral transitional vertebra (LSTV) with computed tomography (CT) and (2) correlate LSTV presence with lumbar disc degeneration at each level by magnetic resonance imaging.
  
  
  BACKGROUND
  LSTV is a frequently observed abnormality. Although its prevalence in patients with adolescent idiopathic scoliosis (AIS) has been shown, no studies have yet examined the clinical importance of LSTV in patients with AIS.
  
  
  METHODS
  This study included 385 consecutive patients who underwent surgery for AIS at a single center. Plain radiographs and CT scans were used to detect LSTV. Disc degeneration was analyzed at the L3-4, L4-5, and L5-S1 disc levels with magnetic resonance imaging. The difference in disc degeneration at each level by the presence of LSTV was also analyzed. The effect of lumbar curve type on the disc degeneration of each level was then determined. To minimize confounding factors, logistic regression analysis was performed.
  
  
  RESULTS
  The overall prevalence of LSTV in patients with AIS confirmed by CT scans was 12.2% (47/385). The proportion of grade II or more disc degeneration at the L4-5 level was higher in the LSTV(+) group than in the LSTV(-) group (29.8% vs.19.2%) although it was not statistically significant (P = 0.093). Large lumbar curves showed a positive correlation with disc degeneration at the L5-S1 level (P = 0.022).
  
  
  CONCLUSIONS
  The prevalence of LSTV in patients with AIS was 12.2%. A trend of early degeneration in L4-5 level discs was found in patients with AIS with LSTV although it was not statistically confirmed. Disc degeneration at the L5-S1 level is related to a large lumbar curve. If patients with AIS with large lumbar curves have LSTV, consideration should be given to stopping the distal fusion at L3 instead of L4.
  
  
  METHODS
  4.
authors.affiliation: From the Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Choon Sung
authors.initials: CS
authors.lastname: Lee
authors.forename: Jung-Ki
authors.initials: JK
authors.lastname: Ha
authors.forename: Dae Geun
authors.initials: DG
authors.lastname: Kim
authors.forename: Chang Ju
authors.initials: CJ
authors.lastname: Hwang
authors.forename: Dong-Ho
authors.initials: DH
authors.lastname: Lee
authors.forename: Jae Hwan
authors.initials: JH
authors.lastname: Cho
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D007403:Intervertebral Disc / Q000601:surgery; D055959:Intervertebral Disc Degeneration / Q000601:surgery*; D007405:Intervertebral Disc Displacement / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000601:surgery*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D012189:Retrospective Studies; D012600:Scoliosis / Q000601:surgery*; D013123:Spinal Fusion / Q000379:methods; D016896:Treatment Outcome