title: The benefit of nonoperative treatment for adult spinal deformity: identifying predictors for reaching a minimal clinically important difference.
abstract: BACKGROUND
  Adult spinal deformity (ASD) patients may gain minimal clinically important difference (MCID) in one or more of the health-related quality-of-life instruments without surgical intervention. The present study identifies the baseline characteristics of this subset of nonoperative patients and proposes predictors of those most likely to benefit.
  
  
  OBJECTIVE
  The study aims to determine the factors that affect likelihood of nonoperative patients to reach MCID.
  
  
  METHODS
  This is a retrospective review of a prospective, multicenter database.
  
  
  METHODS
  The study includes nonoperative ASD patients.
  
  
  METHODS
  Health-related quality-of-life measures, including the Scoliosis Research Society (SRS)-22 questionnaire, were used.
  
  
  METHODS
  The study used a multicenter database of 215 nonoperative patients with ASD and with minimum 2-year follow-up. Using a multivariate analysis, two groups were compared to identify possible predictors: those who reached MCID in the SRS pain or activity (N=86) at 2 years and those who did not reach MCID (N=129). A subgroup multivariate analysis of patients with a deficit (potential improvement) in both SRS pain and activity (N=84) was performed. Data collection was supported by a grant from DePuy for the International Spine Study Group Foundation.
  
  
  RESULTS
  At baseline, the nonoperative patients who reached MCID had a significantly lower SRS pain score (3.0 vs. 3.6), smaller thoracolumbar Cobb (TL Cobb) angle (29.6° vs. 36.5°; 87 patients with SRS-Schwab classification of lumbar or double), lower sacral slope (33.1° vs. 36.4°), and less lumbar lordosis (46.5° vs. 52.8°) (all p<.05). The SRS pain and TL Cobb were significant predictors for reaching MCID. The pelvic incidence minus lumbar lordosis (PI-LL) was significant on univariate analysis but not on multivariate analysis (7.5° vs. 2.6°; p=.14). In the subset of severely disabled patients, worse vertebral obliquity was a predictor for not achieving MCID (p<.05).
  
  
  CONCLUSIONS
  Nonoperative ASD patients who achieved MCID in SRS activity or pain had a lower baseline SRS pain score and less coronal deformity in the TL region. Greater baseline pain offers significant room for potential improvement, which may be important in identifying ASD patients who have the potential to reach MCID nonoperatively. Coronal deformities in the TL region and associated vertebral obliquity may negatively impact potential for improvement in nonoperative care.
authors.affiliation: Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, 301 East 17th Street, New York, NY 10003, USA.
authors.forename: Shian
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, 301 East 17th Street, New York, NY 10003, USA.
authors.forename: Bassel G
authors.initials: BG
authors.lastname: Diebo
authors.affiliation: Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, 301 East 17th Street, New York, NY 10003, USA.
authors.forename: Jensen K
authors.initials: JK
authors.lastname: Henry
authors.affiliation: Department of Neurosurgery, University of Virginia Medical Center, Charlottesville, VA 800212, USA.
authors.forename: Justin S
authors.initials: JS
authors.lastname: Smith
authors.affiliation: Department of Orthopaedic Surgery, Baylor Scoliosis Center, 4708 Alliance Boulevard, #810, Plano, TX, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Hostin
authors.affiliation: Department of Orthopaedic Surgery, Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021, USA.
authors.forename: Matthew E
authors.initials: ME
authors.lastname: Cunningham
authors.affiliation: Scripps Clinic Torrey Pines, 10666 N Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Gregory
authors.initials: G
authors.lastname: Mundis
authors.affiliation: Department of Neurosurgery, University of California, San Francisco Medical Center, 400 Parnassus Street, San Francisco, CA, USA.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Ames
authors.affiliation: Department of Orthopaedic Surgery, University of Kansas Medical Center, 3901 Rainbow Blvd, Kansas City, KS, 66160, USA.
authors.forename: Douglas
authors.initials: D
authors.lastname: Burton
authors.affiliation: Rocky Mountain Scoliosis and Spine Center, 2055 High St, Denver, CO 80205, USA.
authors.forename: Shay
authors.initials: S
authors.lastname: Bess
authors.affiliation: Department of Orthopaedic Surgery, San Diego Center for Spinal Disorders, 4130 La Jolla Village Dr # 300, La Jolla, CA, 92037, USA.
authors.forename: Behrooz
authors.initials: B
authors.lastname: Akbarnia
authors.affiliation: Department of Orthopaedic Surgery, Oregon Health Sciences University, 3181 SW Sam Jackson Park Rd, Portland, OR, 97239, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Hart
authors.affiliation: Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, 301 East 17th Street, New York, NY 10003, USA.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Passias
authors.affiliation: Department of Orthopaedic Surgery, Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021, USA.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Schwab
authors.affiliation: Department of Orthopaedic Surgery, Baylor Scoliosis Center, 4708 Alliance Boulevard, #810, Plano, TX, USA. Electronic address: virginie.lafage@gmail.com.
authors.forename: Virginie
authors.initials: V
authors.lastname: Lafage
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008141:Lordosis / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D012600:Scoliosis / Q000473:pathology / Q000628:therapy*; D015599:Trauma Severity Indices; D016896:Treatment Outcome
keywords: HRQOL; Health-related quality of life; Nonoperative; Outcomes; Spinal deformity; Treatment