title: Can c7 plumbline and gravity line predict health related quality of life in adult scoliosis?
abstract: METHODS
  This study prospectively evaluated the health related quality of life (HRQOL) of 73 adults presenting with scoliosis at a single institution, as related to their spinal (C7 plumbline) and global (gravity line) balance.
  
  
  OBJECTIVE
  To assess the influence of sagittal and coronal balance on HRQOL in adult scoliosis.
  
  
  BACKGROUND
  Many surgeons believe that achieving adequate spinal balance is important in the management of adult spinal deformity, but the evidence supporting this concept remains limited. A previous study has found weak correlations between sagittal spinal balance and HRQOL in adult spinal deformity, but this finding has never been confirmed independently. In addition, although the use of the gravity line is gaining interest in the evaluation of global balance, it remains unknown if this parameter is associated with HRQOL.
  
  
  METHODS
  During a 1-year period, 73 consecutive new patients presenting with unoperated adult scoliosis and requiring full spine standing radiographs were evaluated using a force plate in order to simultaneously assess the gravity line. All patients also completed the Oswestry Disability Index (ODI) questionnaire to assess the HRQOL. Spinal balance was evaluated from the C7 plumbline and global balance from the gravity line, respectively. C7 plumbline and gravity line were both assessed with respect to the posterosuperior corner of the S1 vertebral body and central sacral vertebral line in the sagittal and coronal plane, respectively. C7 plumbline and gravity line, as well as their relative position, were correlated with the ODI, using Spearman coefficients.
  
  
  RESULTS
  Sagittal spinal (C7 plumbline) and global (gravity line) balance, as well as their relative position were significantly related to the ODI. A poor ODI (>34) was associated with a sagittal C7 plumbline greater than 6 cm, a sagittal gravity line greater than 6 cm, and a C7 plumbline in front of the gravity line. Correlations between coronal balance and the ODI were not statistically significant.
  
  
  CONCLUSIONS
  Sagittal spinal and global balance was strongly related to the ODI in adults with scoliosis. The observed correlation coefficients were higher than those reported in the only previous study suggesting the detrimental association of positive sagittal balance on ODI in adult spinal deformity. Coronal spinal and global balance did not influence the ODI in the current study cohort. Thisstudy underlines the relevance of C7 plumbline and gravity line in the evaluation of spinal and global balance, and lends further support to the philosophy of achieving adequate sagittal balance in the management of adult spinal deformity, especially in patients older than 50 years old with degenerative scoliosis.
authors: From the Twin Cities Spine Center, Minneapolis, MN.
authors: Jean-Marc
authors: JM
authors: Mac-Thiong
authors: Ensor E
authors: EE
authors: Transfeldt
authors: Amir A
authors: AA
authors: Mehbod
authors: Joseph H
authors: JH
authors: Perra
authors: Francis
authors: F
authors: Denis
authors: Timothy A
authors: TA
authors: Garvey
authors: John E
authors: JE
authors: Lonstein
authors: Chunhui
authors: C
authors: Wu
authors: Christopher W
authors: CW
authors: Dorman
authors: Robert B
authors: RB
authors: Winter
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology; D015331:Cohort Studies; D004185:Disability Evaluation; D005260:Female; D006112:Gravitation; D006801:Humans; D008297:Male; D008875:Middle Aged; D010808:Physical Examination / Q000379:methods; D011187:Posture / Q000502:physiology*; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011788:Quality of Life / Q000523:psychology; D011859:Radiography; D015203:Reproducibility of Results; D012600:Scoliosis / Q000175:diagnosis* / Q000503:physiopathology* / Q000523:psychology; D013130:Spinal Stenosis / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D013131:Spine / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D011795:Surveys and Questionnaires; D055815:Young Adult