title: Sagittal Vertical Axias, Spinosacral Angle, Spinopelvic Angle, and T1 Pelvic Angle: Which Parameters May Effectively Predict the Quality of Life in Ankylosing Spondylitis Patients With Thoracolumbar Kyphosis?
abstract: METHODS
  This is a retrospective study.
  
  
  OBJECTIVE
  To identify the relationship between global sagittal alignment and health-related quality of life (HRQoL) in ankylosing spondylitis (AS) patients with thoracolumbar kyphosis.
  
  
  BACKGROUND
  Little data are available on correlation between global sagittal alignment and HRQoL in AS.
  
  
  METHODS
  A total of 107 AS patients were included in this study. The radiographic parameters were measured on lateral radiographs of the whole spine, including sagittal vertical axias (SVA), spinosacral angle (SSA), spinopelvic angle (SPA), and T1 pelvic angle (TPA). HRQoL was assessed using the oswestry disability index questionnaire, the bath ankylosing spondylitis disease activity index, the bath ankylosing spondylitis functional index, and short form-36 questionnaire. The patients were divided into 2 groups: group A (n=76, global kyphosis≤70 degrees), group B (n=31, global kyphosis>70 degrees). Statistical analysis was performed to identify significant differences between these 2 groups. In addition, correlation analysis and multiple regression analysis between radiologic parameters and clinical questionnaires were conducted.
  
  
  RESULTS
  With respect to SVA, SSA, SPA, TPA, and HRQoL scores, significant differences were observed between 2 groups (P<0.05). Also, SVA, SSA, SPA, and TPA were significantly related to HRQoL. Multiple regression analysis revealed that SVA, SSA, SPA, and TPA were significant parameters in the prediction of HRQoL in AS patients with thoracolumbar kyphosis. Of note, HRQoL related much more to SSA and SPA than SVA and TPA.
  
  
  CONCLUSIONS
  AS patients with moderate and severe deformity were demonstrated to be significantly different in terms of SVA, SSA, SPA, TPA, and HRQoL. Moreover, SVA, SSA, SPA, and TPA correlated with HRQoL significantly. In particular, SSA and SPA could better predict HRQoL than SVA and TPA in AS patients with thoracolumbar kyphosis.
authors.affiliation: Department of Spine Surgery, Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.
authors.forename: Yun-Peng
authors.initials: YP
authors.lastname: Zhang
authors.forename: Bang-Ping
authors.initials: BP
authors.lastname: Qian
authors.forename: Yong
authors.initials: Y
authors.lastname: Qiu
authors.forename: Zhe
authors.initials: Z
authors.lastname: Qu
authors.forename: Sai-Hu
authors.initials: SH
authors.lastname: Mao
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang
authors.forename: Ze-Zhang
authors.initials: ZZ
authors.lastname: Zhu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D003710:Demography; D005260:Female; D006801:Humans; D007738:Kyphosis / Q000150:complications / Q000503:physiopathology*; D008159:Lumbar Vertebrae / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000503:physiopathology*; D011788:Quality of Life; D012044:Regression Analysis; D012447:Sacrum / Q000503:physiopathology*; D013167:Spondylitis, Ankylosing / Q000150:complications / Q000503:physiopathology*; D013904:Thoracic Vertebrae / Q000503:physiopathology*; D055815:Young Adult