title: Magnitude of preoperative cervical lordotic compensation and C2-T3 angle are correlated to increased risk of postoperative sagittal spinal pelvic malalignment in adult thoracolumbar deformity patients at 2-year follow-up.
abstract: BACKGROUND
  Cervical deformity (CD) is prevalent among patients with adult spinal deformity (ASD). The effect of baseline cervical alignment on achieving optimal thoracolumbar alignment in ASD surgery is unclear.
  
  
  OBJECTIVE
  This study assesses the relationship between preoperative (preop) cervical spinal parameters and global alignment after thoracolumbar ASD surgery at 2-year follow-up.
  
  
  METHODS
  This study is a retrospective review of a multicenter, prospective database.
  
  
  METHODS
  Surgical ASD patients with 2-year follow-up and cervical X-rays were included.
  
  
  METHODS
  The outcome measures were radiographic parameters and self-reported health-related quality-of-life measures (Short-Form 36 [SF-36], Oswestry Disability Index [ODI], and Scoliosis Research Society 22 [SRS-22]).
  
  
  METHODS
  Surgical ASD patients of 18 years and older with scoliosis greater than or equal to 20° and one of the following radiographic parameters were included: sagittal vertical axis (SVA) greater than or equal to 5 cm, pelvic tilt (PT) greater than or equal to 25°, or thoracic kyphosis (TK) greater than 60°. The SRS-Schwab sagittal modifiers (PT, global alignment, and pelvic incidence and lumbar lordosis [PI-LL]) were assessed at 2-year postoperatively as either normal ("0") or abnormal ("+" or "++"). Patients were classified in the aligned group (AG) or malaligned group (MG) at 2-year follow-up if all three sagittal modifiers were normal or abnormal, respectively. Patients were assessed for CD based on the following criteria: C2-C7 SVA greater than 4 cm, C2-C7 SVA less than 4 cm, cervical kyphosis (CL greater than 0), cervical lordosis (CL less than 0), any deformity (C2-C7 SVA greater than 4 cm or CL greater than 0), and both CD (C2-C7 SVA greater than 4 cm and CL greater than 0). Univariate testing was performed using t or chi-square test, looking at the following preop parameters: CD, C2-C7 SVA, C2-T3 SVA, CL, T1 slope (T1S), T1S-CL, C2-T3 angle, LL, TK, PT, C7-S1 SVA, and PI-LL.
  
  
  RESULTS
  One hundred four patients met the initial inclusion criteria with 70 in the AG and 34 in MG. Preoperative, patients in the MG had a higher CL (11.7 vs. 4.9, p=.03), higher C2-T3 angle (13.59 vs 4.9 p=.01), higher PT (p<.0001), higher SVA (p<.0001), and higher PI-LL (p<.0001) compared with the AG. Interestingly, the prevalence of CD at baseline was similar for both groups. There was no statistically significant difference among groups in the amount of improvement more than 2 years on the ODI or the Physical Component Summary of SF-36.
  
  
  CONCLUSIONS
  Patients with sagittal spinal malalignment associated with significant cervical compensatory lordosis are at increased risk of realignment failure at 2-year follow-up. Assessment of the degree of cervical compensation may be helpful in preop evaluation to assist in realignment outcome prediction.
authors: Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, 301 E 17th St #1402, New York, NY 10003, USA. Electronic address: Peter.Passias@nyumc.org.
authors: Peter G
authors: PG
authors: Passias
authors: Department of Orthopaedic Surgery, University of Calgary, 3330 Hospital Dr NW, Calgary, AB T2N 4N1, Canada.
authors: Alexandra
authors: A
authors: Soroceanu
authors: Department of Neurological Surgery, Northwestern University, Feinberg School of Medicine, 303 E Chicago Ave., Chicago, IL 60611, USA.
authors: Justin
authors: J
authors: Scheer
authors: Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, 301 E 17th St #1402, New York, NY 10003, USA.
authors: Sun
authors: S
authors: Yang
authors: Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, 301 E 17th St #1402, New York, NY 10003, USA.
authors: Anthony
authors: A
authors: Boniello
authors: Department of Neurosurgery, University of Virginia Medical Center, 1215 Lee St, Charlottesville, VA 22903, USA.
authors: Justin S
authors: JS
authors: Smith
authors: Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, 301 E 17th St #1402, New York, NY 10003, USA.
authors: Themistocles
authors: T
authors: Protopsaltis
authors: Department of Orthopaedic Surgery, Hospital for Special Surgery, 535 E 70th St, New York, NY 10021, USA.
authors: Han J
authors: HJ
authors: Kim
authors: Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, 301 E 17th St #1402, New York, NY 10003, USA.
authors: Frank
authors: F
authors: Schwab
authors: Department of Orthopaedic Surgery, University of California-Davis, 4860 Y St, Sacramento, CA 95817, USA.
authors: Munish
authors: M
authors: Gupta
authors: Department of Orthopaedic Surgery, University of California-Davis, 4860 Y St, Sacramento, CA 95817, USA.
authors: Eric
authors: E
authors: Klineberg
authors: San Diego Center for Spinal Disorders, 4130 La Jolla Village Dr, La Jolla, CA 92037, USA.
authors: Gregory
authors: G
authors: Mundis
authors: Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, 301 E 17th St #1402, New York, NY 10003, USA.
authors: Renaud
authors: R
authors: Lafage
authors: Department of Orthopaedic Surgery, Oregon Health and Science University, 3181 S.W. Sam Jackson Park Rd, Portland, OR 97239, USA.
authors: Robert
authors: R
authors: Hart
authors: Department of Neurological Surgery, Northwestern University, Feinberg School of Medicine, 303 E Chicago Ave., Chicago, IL 60611, USA.
authors: Christopher
authors: C
authors: Shaffrey
authors: Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, 301 E 17th St #1402, New York, NY 10003, USA.
authors: Virginie
authors: V
authors: Lafage
authors: Department of Neurosurgery, University of California-San Francisco, 505 Parnassus Ave., San Francisco, CA 94143, USA.
authors: Christopher
authors: C
authors: Ames
mesh_terms: D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007738:Kyphosis / Q000000981:diagnostic imaging / Q000601:surgery*; D008141:Lordosis / Q000000981:diagnostic imaging / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011379:Prognosis; D011788:Quality of Life; D011859:Radiography; D012189:Retrospective Studies; D012306:Risk; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000601:surgery*; D013904:Thoracic Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*
keywords: Adult spinal deformity; Alignment; Cervical deformity; HRQOL; Outcome; Radiographic parameter