title: T1 pelvic angle: a new predictor for postoperative sagittal balance and clinical outcomes in adult scoliosis.
abstract: METHODS
  A retrospective radiographical study.
  
  
  OBJECTIVE
  To compare the prediction abilities of T1 pelvic angle (TPA) and other parameters for postoperative sagittal balance, and investigate the relationships between these parameters and health-related quality of life.
  
  
  BACKGROUND
  Using sagittal vertical axis (SVA) to assess sagittal alignment fails to take account of the pelvic compensation. A new parameter, TPA, has been recommended to represent the global sagittal balance of adult scoliosis.
  
  
  METHODS
  A retrospective review was performed on patients with adult scoliosis undergoing correction surgery from May 2009 to March 2013. The Spearman ρ was used to determine the correlations between the radiographical parameters (preoperative, postoperative, and changes) and the overall Oswestry Disability Index (ODI), visual analogue scale (VAS), and Scoliosis Research Society-22 (SRS-22) questionnaire scores.
  
  
  RESULTS
  Significant correlations were found between the changes of TPA and the changes of lumbar lordosis, pelvic tilt, sacral slope, pelvic incidence, SVA, spinosacral angle, ODI, VAS, SRS-22, and pedicle subtraction osteotomy (PSO) degrees (P < 0.05). The changes of SVA were significantly related to the changes of lumbar lordosis, TPA, C7-sacrofemoral distance, ODI, VAS, SRS-22 (P < 0.05) but not PSO degrees (P > 0.05). Significant correlations were found between the changes of spinosacral angle and the changes of thoracolumbar kyphosis, TPA, ODI, VAS, SRS-22, and PSO degrees (P < 0.05). The changes of C7 plumb line to sacrofemoral distance ratio were significantly related to the changes of SVA (P < 0.05), but not the changes of ODI, VAS, SRS-22, or PSO degrees (P > 0.05).
  
  
  CONCLUSIONS
  TPA could better reflect the postoperative changes of sagittal alignment and health-related quality of life for patients with adult scoliosis. Moreover, the changes of TPA are strongly correlated to the osteotomy degrees for PSO and, TPA could be used as a reference parameter in surgical planning.
  
  
  METHODS
  4.
authors.affiliation: From the Department of Spine Surgery, the Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Qiao
authors.forename: Feng
authors.initials: F
authors.lastname: Zhu
authors.forename: Leilei
authors.initials: L
authors.lastname: Xu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.forename: Zezhang
authors.initials: Z
authors.lastname: Zhu
authors.forename: Bangping
authors.initials: B
authors.lastname: Qian
authors.forename: Xu
authors.initials: X
authors.lastname: Sun
authors.forename: Yong
authors.initials: Y
authors.lastname: Qiu
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010027:Osteotomy; D010388:Pelvis / Q000000981:diagnostic imaging / Q000503:physiopathology; D004856:Postural Balance; D011788:Quality of Life; D011859:Radiography; D012189:Retrospective Studies; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D016896:Treatment Outcome