title: Radiographic Outcomes of Adult Spinal Deformity Correction: A Critical Analysis of Variability and Failures Across Deformity Patterns.
abstract: METHODS
  Multicenter, prospective, consecutive, surgical case series from the International Spine Study Group.
  
  
  OBJECTIVE
  To evaluate the effectiveness of surgical treatment in restoring spinopelvic (SP) alignment.
  
  
  BACKGROUND
  Pain and disability in the setting of adult spinal deformity have been correlated with global coronal alignment (GCA), sagittal vertical axis (SVA), pelvic incidence/lumbar lordosis mismatch (PI-LL), and pelvic tilt (PT). One of the main goals of surgery for adult spinal deformity is to correct these parameters to restore harmonious SP alignment.
  
  
  METHODS
  Inclusion criteria were operative patients (age greater than 18 years) with baseline (BL) and 1-year full-length X-rays. Thoracic and thoracolumbar Cobb angle and previous mentioned parameters were calculated. Each parameter at BL and 1 year was categorized as either pathological or normal. Pathologic limits were: Cobb greater than 30°, GCA greater than 40 mm, SVA greater than 40 mm, PI-LL greater than 10°, and PT greater than 20°. According to thresholds, corrected or worsened alignment groups of patients were identified and overall radiographic effectiveness of procedure was evaluated by combining the results from the coronal and sagittal planes.
  
  
  RESULTS
  A total of 161 patients (age, 55 ± 15 years) were included. At BL, 80% of patients had a Cobb angle greater than 30°, 25% had a GCA greater than 40 mm, and 42% to 58% had a pathological sagittal parameter of PI-LL, SVA, and/or PT. Sagittal deformity was corrected in about 50% of cases for patients with pathological SVA or PI-LL, whereas PT was most commonly worsened (24%) and least often corrected (24%). Only 23% of patients experienced complete radiographic correction of the deformity.
  
  
  CONCLUSIONS
  The frequency of inadequate SP correction was high. Pelvic tilt was the parameter least likely to be well corrected. The high rate of SP alignment failure emphasizes the need for better preoperative planning and intraoperative imaging.
authors.affiliation: Department of Orthopedic Surgery, NYU Hospital for Joint Diseases, 306 E. 15th Street, Suite 1F, New York, NY 10003, USA; Laboratory of Biomechanics, Arts et Metier ParisTech, 51, Boulevard de l'hopital, 75013 Paris, France.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Moal
authors.affiliation: Department of Orthopedic Surgery, NYU Hospital for Joint Diseases, 306 E. 15th Street, Suite 1F, New York, NY 10003, USA.
authors.forename: Frank
authors.initials: F
authors.lastname: Schwab
authors.affiliation: Department of Neurosurgery, University of California San Francisco, 400 Parnassus Ave, San Francisco, CA 94122, USA.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Ames
authors.affiliation: Department of Neurosurgery, University of Virginia Medical Center, Neurosurgery Home, PO Box 800212, Charlottesville, VA 22908, USA.
authors.forename: Justin S
authors.initials: JS
authors.lastname: Smith
authors.affiliation: Department of Orthopedic Surgery, NYU Hospital for Joint Diseases, 306 E. 15th Street, Suite 1F, New York, NY 10003, USA.
authors.forename: Devon
authors.initials: D
authors.lastname: Ryan
authors.affiliation: Department of Neurosurgery, University of California San Francisco, 400 Parnassus Ave, San Francisco, CA 94122, USA.
authors.forename: Praveen V
authors.initials: PV
authors.lastname: Mummaneni
authors.affiliation: Department of Orthopedic Surgery, San Diego Center for Spinal Disorders, 4130 La Jolla Village Dr., Suite 300, La Jolla, CA 92037, USA.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Mundis
authors.affiliation: Department of Orthopedic Surgery, NYU Hospital for Joint Diseases, 306 E. 15th Street, Suite 1F, New York, NY 10003, USA.
authors.forename: Jamie S
authors.initials: JS
authors.lastname: Terran
authors.affiliation: Department of Orthopedic Surgery, University of California Davis, 3301 C St., Suite 1500, Sacramento, CA 95816, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Klineberg
authors.affiliation: Department of Orthopedic Surgery, Oregon Health Sciences University, 3181 SW Sam Jackson Park Rd, Portland, OR, USA.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Hart
authors.affiliation: Department of Orthopedic Surgery, Hospital for Special Surgery, New York, NY, USA.
authors.forename: Oheneba
authors.initials: O
authors.lastname: Boachie-Adjei
authors.affiliation: Department of Neurosurgery, University of Virginia Medical Center, Neurosurgery Home, PO Box 800212, Charlottesville, VA 22908, USA.
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Shaffrey
authors.affiliation: Laboratory of Biomechanics, Arts et Metier ParisTech, 51, Boulevard de l'hopital, 75013 Paris, France.
authors.forename: Wafa
authors.initials: W
authors.lastname: Skalli
authors.affiliation: Department of Orthopedic Surgery, NYU Hospital for Joint Diseases, 306 E. 15th Street, Suite 1F, New York, NY 10003, USA. Electronic address: virginie.lafage@gmail.com.
authors.forename: Virginie
authors.initials: V
authors.lastname: Lafage
keywords: Adult spinal deformity; Radiographic effectiveness; SRS–Schwab classification; Surgical treatment; spinopelvic alignment