title: The Spine Instability Neoplastic Score: an independent reliability and reproducibility analysis.
abstract: BACKGROUND
  Metastatic vertebral instability has not yet been clearly defined in the literature; there still exists a paucity of reliable criteria to assess the risk of vertebral collapse.
  
  
  OBJECTIVE
  We performed an independent interobserver and intraobserver agreement evaluation of the Spine Instability Neoplastic Score (SINS) and correlated the score with selected clinical cases and the treatment they received.
  
  
  METHODS
  Independent reliability study for the newly created SINS.
  
  
  METHODS
  Thirty patients who underwent either radiotherapy alone or surgery followed by radiotherapy were randomly selected from the orthopedic surgery and radiotherapy department's databases.
  
  
  METHODS
  Patients were rated and classified for spinal stability using SINS. Intraclass correlation coefficient (ICC) and Fleiss's kappa measures were occupied for reliability analysis.
  
  
  METHODS
  Patients who underwent either radiotherapy alone or surgery followed by radiotherapy were randomly selected and classified for spinal stability using the SINS by orthopedic surgeons and nonorthopedic oncology specialists. ICC and Fleiss's kappa were calculated for inter- and intraobserver agreement. A comparative analysis of SINS and the actual management was also conducted.
  
  
  RESULTS
  Interobserver ICC reliability for the SINS was 0.79; κ values for location, pain, bone quality, alignment, vertebral body collapse, and posterolateral involvement were 0.81, 0.58, 0.21, 0.45, 0.42, and 0.29 respectively. Intraobserver ICC for the SINS scores was 0.96; ICC values for the same components were 0.98, 0.98, 0.87, 0.88, 0.92, and 0.86, respectively. Potentially unstable lesions (SINS score≥7) were operated on in 62.5%.
  
  
  CONCLUSIONS
  SINS seem to be a reproducible tool that could be used equally by multiple specialists to estimate metastatic vertebral stability; however, prospective clinical validation is still pending.
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Pontificia Universidad Católica de Chile, Marcoleta 352, Santiago, Chile. Electronic address: macampos@med.puc.cl.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Campos
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Pontificia Universidad Católica de Chile, Marcoleta 352, Santiago, Chile.
authors.forename: Julio
authors.initials: J
authors.lastname: Urrutia
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Pontificia Universidad Católica de Chile, Marcoleta 352, Santiago, Chile.
authors.forename: Tomás
authors.initials: T
authors.lastname: Zamora
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Pontificia Universidad Católica de Chile, Marcoleta 352, Santiago, Chile.
authors.forename: Javier
authors.initials: J
authors.lastname: Román
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Pontificia Universidad Católica de Chile, Marcoleta 352, Santiago, Chile.
authors.forename: Valentina
authors.initials: V
authors.lastname: Canessa
authors.affiliation: Radiotherapy Service, Hemato-oncology Department, Pontificia Universidad Católica de Chile, Diagonal Paraguay 319, Santiago, Chile.
authors.forename: Yerko
authors.initials: Y
authors.lastname: Borghero
authors.affiliation: Palliative Medicine Service, Internal Medicine Department, Pontificia Universidad Católica de Chile, Lira 63, Santiago, Chile.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Palma
authors.affiliation: Department of Orthopaedic Surgery, School of Medicine, Pontificia Universidad Católica de Chile, Marcoleta 352, Santiago, Chile.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Molina
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005598:Fractures, Spontaneous / Q000000981:diagnostic imaging / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D009985:Orthopedics; D011859:Radiography; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000209:etiology*; D013125:Spinal Neoplasms / Q000150:complications / Q000000981:diagnostic imaging / Q000556:secondary*
keywords: Impending fractures; Observer agreement; Reliability analysis; Spinal Instability Neoplastic Score; Spinal instability; Spinal metastasis