title: Thoracic curve correction after posterior fusion and instrumentation of structural lumbar curves in patients with adolescent idiopathic scoliosis.
abstract: BACKGROUND
  Spontaneous thoracic curve correction may occur following selective anterior spinal fusion in patients with adolescent idiopathic scoliosis (AIS). However, a few reports have described outcomes in patients following selective posterior fusion. The aim of this retrospective study was to assess curve correction in AIS patients with major lumbar curves and secondary thoracic curves after selective posterior fusion of the major curve.
  
  
  METHODS
  The records of 42 AIS patients with major lumbar and minor thoracic curves who had received selective posterior lumbar fusion with segmental pedicle screw fixation were examined. Preoperative and follow-up radiographs were examined and the following were determined: curve flexibility, Cobb angle measurements of the major and minor curves, thoracolumbar/lumbar and thoracic Cobb measurements. Also, thoracolumbar/lumbar to thoracic Cobb ratios were determined. Minimum follow-up was 2 years. Patients were compared with respect to whether final thoracic curve improvement was (group A) or was not (group B) apparent. Improvement was indicated by a final thoracic curve that was less than the preoperative thoracic curve.
  
  
  RESULTS
  Thoracic curve improvement was apparent in 32 of 42 patients after surgery. The mean preoperative thoracic curve in group A was 22.5° and 15.0° at follow-up, while corresponding values in group B were 35.0° and 39.8°. There were no cases in group A and eight cases in group B in which the preoperative thoracic curve was >30°. All patients in group B had preoperative thoracic curves on lateral bending >20°. Thoracic curvature at final follow-up was strongly correlated with preoperative thoracic curvature (r = 0.911) and thoracic curvature on lateral bending (r = 0.948).
  
  
  CONCLUSIONS
  Selective posterior fusion with segmental pedicle screw fixation in patients with major lumbar AIS resulted in curve correction in the majority of cases. Preoperative thoracic curvature and thoracic curvature on lateral bending were strongly correlated with the final thoracic curvature.
authors.affiliation: Orthopedic Department, Changhai Hospital, Shanghai, People's Republic of China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Xiutong
authors.initials: X
authors.lastname: Fang
authors.forename: Yujie
authors.initials: Y
authors.lastname: Sun
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Hongzhi
authors.initials: H
authors.lastname: Liu
authors.forename: Shisheng
authors.initials: S
authors.lastname: He
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhu
authors.forename: Lugang
authors.initials: L
authors.lastname: Zhou
authors.forename: Hao
authors.initials: H
authors.lastname: Su
authors.forename: Hongtao
authors.initials: H
authors.lastname: Liu
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Ni
mesh_terms: D000293:Adolescent; D001863:Bone Screws; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D011859:Radiography; D012189:Retrospective Studies; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery; D016896:Treatment Outcome