title: Progression of Coronal Cobb Angle After Short-Segment Lumbar Interbody Fusion in Patients with Degenerative Lumbar Stenosis.
abstract: OBJECTIVE
  The progression of scoliosis after fusion surgery is a poor prognostic factor of long-term outcomes in patients with degenerative lumbar stenosis (DLS). In this study we aimed to investigate changes in coronal alignment and identify risk factors related to progression of scoliosis after fusion.
  
  
  METHODS
  There were 540 patients with symptomatic DLS treated by short-segment lumbar fusion surgery. Among them, 50 patients had coronal Cobb angles >10° at the final follow-up. Sixteen patients had increases >5° (progression group), and 34 patients had increases <5° (nonprogression group). Radiologic parameters that may affect the progression of scoliosis were compared.
  
  
  RESULTS
  The mean progression of the Cobb angle was 7.92° in the progression group and 1.25° in the nonprogression group. The progression group had significantly longer follow-up periods and a lower preoperative Cobb angle. The apical vertebra (AV) of the major curve was more frequently thoracic in the progression group. Progression of the Cobb angle was correlated with the follow-up period, preoperative Cobb angle, and location of the AV. Multivariate regression analysis showed that progression of the Cobb angle was significantly associated with a lower preoperative Cobb angle, and both facet degeneration of the upper instrumented vertebra at the fusion site and vertebral spur formation on the concave side also appeared to be associated with progression of the Cobb angle.
  
  
  CONCLUSIONS
  The global magnitude of progression of the Cobb angle after short-segment lumbar fusion surgery in patients with DLS is similar to the natural curve progression of adult degenerative scoliosis.
authors.affiliation: Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Nam
authors.initials: N
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Seong
authors.initials: S
authors.lastname: Yi
authors.affiliation: Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Dong Ah
authors.initials: DA
authors.lastname: Shin
authors.affiliation: Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Keung Nyun
authors.initials: KN
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Do Heum
authors.initials: do H
authors.lastname: Yoon
authors.affiliation: Department of Neurosurgery, Spine and Spinal Cord Institute, Yonsei University College of Medicine, Seoul, Korea. Electronic address: hayoon@yuhs.ac.
authors.forename: Yoon
authors.initials: Y
authors.lastname: Ha
mesh_terms: D000328:Adult; D000368:Aged; D003251:Constriction, Pathologic / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000601:surgery; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D055959:Intervertebral Disc Degeneration / Q000000981:diagnostic imaging* / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D012044:Regression Analysis; D012600:Scoliosis / Q000175:diagnosis; D012720:Severity of Illness Index; D013123:Spinal Fusion; D016896:Treatment Outcome
keywords: Degenerative lumbar stenosis; Lumbar fusion surgery; Progression of the Cobb angle