title: Postoperative cervical deformity in 215 thoracolumbar patients with adult spinal deformity: prevalence, risk factors, and impact on patient-reported outcome and satisfaction at 2-year follow-up.
abstract: METHODS
  Retrospective review of prospective multicenter database.
  
  
  OBJECTIVE
  Quantify the incidence of new onset cervical deformity (CD) after adult spinal deformity surgery of the thoracolumbar spine, identify predictors of development, and determine the impact on outcomes.
  
  
  BACKGROUND
  High prevalence of residual CD has been identified after surgical treatment of adult spinal deformity. Development of new onset CD is less understood and its clinical impact unclear.
  
  
  METHODS
  A total of 215 patients with complete 2-year follow-up and full-length radiographs met inclusion criteria. CD was defined by T1 slope minus Cervical Lordosis (CL) more than 20°, C2-C7 sagittal vertical axis more than 40 mm, or C2-C7 kyphosis more than 10°. Univariate analysis was performed using t tests or tests of proportion. Multivariate logistic regression was used to determine independent predictors of new onset CD. The impact of CD on health-related quality of life and satisfaction was measured using repeated measures mixed models or logistic regression as appropriate, accounting for potential confounders.
  
  
  RESULTS
  The overall rate of CD at 2 years after surgery was 63%. Univariate analysis revealed that patients who developed new onset CD postoperatively had higher incidence of diabetes (7.35% vs. 1.28%, P = 0.05), increased preoperative C2-C7 sagittal vertical axis (P = 0.04) and C2 slope (P = 0.038), and smaller diameter rods used at surgery (P = 0.032). Independent predictors of new onset CD at 2 years included: diabetes (odds ratio, 10.49; P = 0.046) and increased preoperative T1 slope minus cervical lordosis (odds ratio, 1.08/º; P = 0.022). Ending instrumentation below T4 was a negative predictor (odds ratio, 0.31; P = 0.019). Patients with and without CD experienced improvements in 2-year 36-Item Short Form Health Survey (P = 0.0001), Oswestry Disability Index (P = 0.0001), and Scoliosis Research Society (P = 0.0001). Rates and overall improvement were similar. CD was not associated with decreased satisfaction (P = 0.28).
  
  
  CONCLUSIONS
  A total of 47.7% of patients without preoperative CD developed new onset postoperative CD after thoracolumbar surgery. Independent predictors of new onset CD at 2 years included diabetes, higher preoperative T1 slope minus cervical lordosis, and ending instrumentation above T4. Significant improvements in health-related quality of life scores occurred despite the development of postoperative CD.
  
  
  METHODS
  2.
authors.affiliation: *Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, New York, NY †Department of Neurosurgery, University of Virginia Medical Center, Charlottesville, VA ‡Department of Neurological Surgery, Northwestern University, Feinberg School of Medicine, Chicago, IL §Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, NY ¶San Diego Center for Spinal Disorders, La Jolla, CA ∥Department of Orthopaedic Surgery, University of California Davis, Sacramento, CA **Department of Neurosurgery, University of California San Francisco, San Francisco, CA; and ††International Spine Study Group, Littleton, CO.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Passias
authors.forename: Alex
authors.initials: A
authors.lastname: Soroceanu
authors.forename: Justin
authors.initials: J
authors.lastname: Smith
authors.forename: Anthony
authors.initials: A
authors.lastname: Boniello
authors.forename: Sun
authors.initials: S
authors.lastname: Yang
authors.forename: Justin K
authors.initials: JK
authors.lastname: Scheer
authors.forename: Frank
authors.initials: F
authors.lastname: Schwab
authors.forename: Christopher
authors.initials: C
authors.lastname: Shaffrey
authors.forename: Han Jo
authors.initials: HJ
authors.lastname: Kim
authors.forename: Themistocles
authors.initials: T
authors.lastname: Protopsaltis
authors.forename: Gregory
authors.initials: G
authors.lastname: Mundis
authors.forename: Munish
authors.initials: M
authors.lastname: Gupta
authors.forename: Eric
authors.initials: E
authors.lastname: Klineberg
authors.forename: Virginie
authors.initials: V
authors.lastname: Lafage
authors.forename: Christopher
authors.initials: C
authors.lastname: Ames
mesh_terms: D002574:Cervical Vertebrae / Q000000981:diagnostic imaging; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011183:Postoperative Complications / Q000000981:diagnostic imaging* / Q000209:etiology; D015995:Prevalence; D011446:Prospective Studies; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D012600:Scoliosis / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000601:surgery; D057566:Self Report; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging* / Q000601:surgery; D016896:Treatment Outcome