title: Radiographical spinopelvic parameters and disability in the setting of adult spinal deformity: a prospective multicenter analysis.
abstract: METHODS
  Prospective multicenter study evaluating operative (OP) versus nonoperative (NONOP) treatment for adult spinal deformity (ASD).
  
  
  OBJECTIVE
  Evaluate correlations between spinopelvic parameters and health-related quality of life (HRQOL) scores in patients with ASD.
  
  
  BACKGROUND
  Sagittal spinal deformity is commonly defined by an increased sagittal vertical axis (SVA); however, SVA alone may underestimate the severity of the deformity. Spinopelvic parameters provide a more complete assessment of the sagittal plane but only limited data are available that correlate spinopelvic parameters with disability. METHODS.: Baseline demographic, radiographical, and HRQOL data were obtained for all patients enrolled in a multicenter consecutive database. Inclusion criteria were: age more than 18 years and radiographical diagnosis of ASD. Radiographical evaluation was conducted on the frontal and lateral planes and HRQOL questionnaires (Oswestry Disability Index [ODI], Scoliosis Research Society-22r and Short Form [SF]-12) were completed. Radiographical parameters demonstrating highest correlation with HRQOL values were evaluated to determine thresholds predictive of ODI more than 40.
  
  
  RESULTS
  Four hundred ninety-two consecutive patients with ASD (mean age, 51.9 yr) were enrolled. Patients from the OP group (n = 178) were older (55 vs. 50.1 yr, P < 0.05), had greater SVA (5.5 vs. 1.7 cm, P < 0.05), greater pelvic tilt (PT; 22° vs. 11°, P < 0.05), and greater pelvic incidence/lumbar lordosis PI/LL mismatch (PI-LL; 12.2 vs. 4.3; P < 0.05) than NONOP group (n = 314). OP group demonstrated greater disability on all HRQOL measures compared with NONOP group (ODI = 41.4 vs. 23.9, P < 0.05; Scoliosis Research Society score total = 2.9 vs. 3.5, P < 0.05). Pearson analysis demonstrated that among all parameters, PT, SVA, and PI-LL correlated most strongly with disability for both OP and NONOP groups (P < 0.001). Linear regression models demonstrated threshold radiographical spinopelvic parameters for ODI more than 40 to be: PT 22° or more (r = 0.38), SVA 47 mm or more (r = 0.47), PI - LL 11° or more (r = 0.45).
  
  
  CONCLUSIONS
  ASD is a disabling condition. Prospective analysis of consecutively enrolled patients with ASD demonstrated that PT and PI-LL combined with SVA can predict patient disability and provide a guide for patient assessment for appropriate therapeutic decision making. Threshold values for severe disability (ODI > 40) included: PT 22° or more, SVA 47 mm or more, and PI - LL 11° or more.
authors.affiliation: Spine Division, NYU Hospital for Joint Diseases, New York, NY, USA.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Schwab
authors.forename: Benjamin
authors.initials: B
authors.lastname: Blondel
authors.forename: Shay
authors.initials: S
authors.lastname: Bess
authors.forename: Richard
authors.initials: R
authors.lastname: Hostin
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Shaffrey
authors.forename: Justin S
authors.initials: JS
authors.lastname: Smith
authors.forename: Oheneba
authors.initials: O
authors.lastname: Boachie-Adjei
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Burton
authors.forename: Behrooz A
authors.initials: BA
authors.lastname: Akbarnia
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Mundis
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Ames
authors.forename: Khaled
authors.initials: K
authors.lastname: Kebaish
authors.forename: Robert A
authors.initials: RA
authors.lastname: Hart
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Farcy
authors.forename: Virginie
authors.initials: V
authors.lastname: Lafage
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000000981:diagnostic imaging*; D011379:Prognosis; D011446:Prospective Studies; D011788:Quality of Life; D011859:Radiography / Q000379:methods; D015203:Reproducibility of Results; D012600:Scoliosis / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000601:surgery*; D012680:Sensitivity and Specificity; D013131:Spine / Q000000981:diagnostic imaging*; D011795:Surveys and Questionnaires; D055815:Young Adult