title: Clinical Improvement Through Surgery for Adult Spinal Deformity: What Can Be Expected and Who Is Likely to Benefit Most?
abstract: METHODS
  Multicenter, prospective, nonconsecutive, surgical case series from the International Spine Study Group.
  
  
  OBJECTIVE
  To evaluate the extent of clinical improvement after surgery for adult spinal deformity (ASD) based on minimal clinically important difference (MCID) and baseline measures.
  
  
  BACKGROUND
  For ASD, evaluation of surgical treatment success using clinical scores should take into account baseline disability and pain and the improvement defined relative to the MCID.
  
  
  METHODS
  Inclusion criteria included operative patients (age >18 years) with baseline and 2-year SRS-22 scores. Normative values for the SRS scores were included and improvement for patients was expressed in number of MCIDs. At baseline, patients were classified by differences in activity and pain scores from normative values in four groups: "worst," "severe," "poor," and, "moderate." At 2 years after surgery, patients were classified into four groups based on their change in SRS score as follows: "no improvement or deterioration," "mediocre," "satisfactory," or "optimal." Distinction among curve types was also performed based on the SRS-Schwab ASD classification.
  
  
  RESULTS
  A total of 223 patients (age = 55 ± 15 years) were included. At baseline, for 77% of the patients, the worst scores were in Activity or Pain. At baseline, the distribution was 36% "worst," 28% "severe," 19% "poor," and 17% "moderate." Patients with sagittal malalignment only were more likely to be in the "worst" state (54%). The overall distribution of improvement was as follows: 24% no improvement or deterioration, 17% mediocre, 25% satisfactory, and 33% optimal. Forty-one percent of baseline "moderate" patients achieved no improvement. Of the baseline "worst" patients, 20% achieved no improvement, and 36% and 19% achieved "satisfactory" and "optimal" improvement, respectively.
  
  
  CONCLUSIONS
  Overall, 24% of patients did not experience improvement after surgery. Patients with baseline severe disability were more likely to perceive improvement than patients with less disability.
  
  
  METHODS
  Level II.
authors.affiliation: Department of Orthopedic Surgery, NYU Hospital for Joint Diseases, New York, NY, 10003, USA; Laboratory of Biomechanics, Arts et Metier ParisTech, Paris, France.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Moal
authors.affiliation: Department of Orthopedic Surgery, NYU Hospital for Joint Diseases, New York, NY, 10003, USA. Electronic address: virginie.lafage@gmail.com.
authors.forename: Virginie
authors.initials: V
authors.lastname: Lafage
authors.affiliation: Department of Neurosurgery, University of Virginia Medical Center, Charlottesville, VA, 22903, USA.
authors.forename: Justin S
authors.initials: JS
authors.lastname: Smith
authors.affiliation: Department of Neurosurgery, University of California San Francisco, San Francisco, CA, 94143, USA.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Ames
authors.affiliation: Department of Orthopedic Surgery, San Diego Center for Spinal Disorders, La Jolla, CA, 92037, USA.
authors.forename: Gregory
authors.initials: G
authors.lastname: Mundis
authors.affiliation: Department of Orthopedic Surgery, NYU Hospital for Joint Diseases, 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, Sacramento, CA, 95817, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Klineberg
authors.affiliation: Department of Orthopedic Surgery, Oregon Health Sciences University, Portland, OR, 97239, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Hart
authors.affiliation: Department of Orthopedic Surgery, Hospital for Special Surgery, New York, NY, 10021, USA.
authors.forename: Oheneba
authors.initials: O
authors.lastname: Boachie-Adjei
authors.affiliation: Department of Orthopedic Surgery, Rocky Mountain Hospital for Children, Denver, CO, 80205, USA.
authors.forename: Shay
authors.initials: S
authors.lastname: Bess
authors.affiliation: Laboratory of Biomechanics, Arts et Metier ParisTech, Paris, France.
authors.forename: Wafa
authors.initials: W
authors.lastname: Skalli
authors.affiliation: Department of Orthopedic Surgery, NYU Hospital for Joint Diseases, New York, NY, 10003, USA.
authors.forename: Frank
authors.initials: F
authors.lastname: Schwab
keywords: Adult spinal deformity; Clinical outcomes; MCID; Normative data; Sagittal alignment