title: Predictors of Revision Surgical Procedure Excluding Wound Complications in Adult Spinal Deformity and Impact on Patient-Reported Outcomes and Satisfaction: A Two-Year Follow-up.
abstract: BACKGROUND
  The surgical procedure to treat adult spinal deformity is challenging, with high rates of complications, including revision procedures performed to repair instrumentation failure or unplanned surgical complications. This study quantifies the incidence of, identifies predictors for, and determines health-related quality-of-life changes associated with revision procedures to treat adult spinal deformity.
  
  
  METHODS
  We analyzed a multicenter database of patients who underwent a surgical procedure for adult spinal deformity, which was defined as having an age of eighteen years or older and scoliosis of ≥20°, sagittal vertical axis of ≥5 cm, pelvic tilt of ≥25°, and/or thoracic kyphosis of >60°. We focused on demographic, radiographic, health-related quality-of-life, and operative data at the two-year follow-up. Patients with primary infections were excluded. Predictive and confounding variables for revisions were identified using univariate analysis and multivariate logistic regression modeling.
  
  
  RESULTS
  Two hundred and forty-three patients were included in this study; of these patients, forty (16.5%) underwent a revision surgical procedure (15% of these at six weeks, 38% between six weeks and one year, and 48% between one and two years). Screw or cage-related implant complications were the most common indications for revision, followed by proximal junctional kyphosis and rod failure. Positive predictors for a revision surgical procedure included total body mass, with an odds ratio of 1.33 (95% confidence interval, 1.04 to 1.70) per 10-kg increase, and preoperative sagittal vertical axis, with an odds ratio of 1.15 (95% confidence interval, 1.04 to 1.28) per 2-cm increase. Factors associated with lower risk of revision included use of bone morphogenetic protein-2 (BMP-2) (odds ratio, 0.16 [95% confidence interval, 0.05 to 0.47]) and greater diameter rods (odds ratio, 0.51 [95% confidence interval, 0.29 to 0.89]). Body mass index, although initially considered a potential predictor for a revision surgical procedure, was not significantly different between primary and revision cohorts on univariate analysis and was therefore not input into the multivariate model. All patients improved in two-year health-related quality-of-life scores; revision subjects had lower overall improvement (Scoliosis Research Society [SRS] score; p = 0.016) from baseline. Revision status did not predict two-year patient satisfaction (p = 0.726), as measured by the SRS Satisfaction domain (SRS-22r).
  
  
  CONCLUSIONS
  Patients with greater preoperative sagittal vertical axis and high total body mass are at a higher risk for a revision surgical procedure following procedures to treat adult spinal deformity. Larger diameter rods and BMP-2 were associated with decreased revision odds. Revisions did not impact patient satisfaction at two years.
  
  
  METHODS
  Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, New York, NY Peter.Passias@nyumc.org.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Passias
authors.affiliation: Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, New York, NY.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Soroceanu
authors.affiliation: Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, New York, NY.
authors.forename: Sun
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, New York, NY.
authors.forename: Frank
authors.initials: F
authors.lastname: Schwab
authors.affiliation: Department of Neurosurgery, University of California San Francisco, San Francisco, California.
authors.forename: Christopher
authors.initials: C
authors.lastname: Ames
authors.affiliation: Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, New York, NY.
authors.forename: Anthony
authors.initials: A
authors.lastname: Boniello
authors.affiliation: Department of Neurological Surgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Justin
authors.initials: J
authors.lastname: Smith
authors.affiliation: Department of Neurosurgery, University of Virginia Medical Center, Charlottesville, Virginia.
authors.forename: Christopher
authors.initials: C
authors.lastname: Shaffrey
authors.affiliation: Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, NY.
authors.forename: Oheneba
authors.initials: O
authors.lastname: Boachie-Adjei
authors.affiliation: San Diego Center for Spinal Disorders, La Jolla, California.
authors.forename: Gregory
authors.initials: G
authors.lastname: Mundis
authors.affiliation: Department of Orthopaedic Surgery, The University of Kansas Hospital, Kansas City, Kansas.
authors.forename: Douglas
authors.initials: D
authors.lastname: Burton
authors.affiliation: Department of Neurosurgery, University of California San Francisco, San Francisco, California.
authors.forename: Eric
authors.initials: E
authors.lastname: Klineberg
authors.affiliation: Department of Orthopaedic Surgery, Oregon Health & Science University, Portland, Oregon.
authors.forename: Robert
authors.initials: R
authors.lastname: Hart
authors.affiliation: University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.
authors.forename: D Kojo
authors.initials: DK
authors.lastname: Hamilton
authors.affiliation: Department of Pediatric Neurological Surgery, Johns Hopkins University, Baltimore, Maryland.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Sciubba
authors.affiliation: Colorado Orthopaedic & Spine Surgery, Denver, Colorado.
authors.forename: Shay
authors.initials: S
authors.lastname: Bess
authors.affiliation: Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, New York, NY.
authors.forename: Virginie
authors.initials: V
authors.lastname: Lafage
mesh_terms: D000328:Adult; D015992:Body Mass Index; D055396:Bone Morphogenetic Protein 2 / Q000627:therapeutic use; D005500:Follow-Up Studies; D005544:Forecasting; D006801:Humans; D007738:Kyphosis; D016015:Logistic Models; D008141:Lordosis; D017060:Patient Satisfaction; D019736:Prostheses and Implants / Q000009:adverse effects; D011788:Quality of Life; D012086:Reoperation / Q000706:statistics & numerical data*; D013122:Spinal Diseases / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2