title: A novel classification system for spinal instability in neoplastic disease: an evidence-based approach and expert consensus from the Spine Oncology Study Group.
abstract: METHODS
  Systematic review and modified Delphi technique.
  
  
  OBJECTIVE
  To use an evidence-based medicine process using the best available literature and expert opinion consensus to develop a comprehensive classification system to diagnose neoplastic spinal instability.
  
  
  BACKGROUND
  Spinal instability is poorly defined in the literature and presently there is a lack of guidelines available to aid in defining the degree of spinal instability in the setting of neoplastic spinal disease. The concept of spinal instability remains important in the clinical decision-making process for patients with spine tumors.
  
  
  METHODS
  We have integrated the evidence provided by systematic reviews through a modified Delphi technique to generate a consensus of best evidence and expert opinion to develop a classification system to define neoplastic spinal instability.
  
  
  RESULTS
  A comprehensive classification system based on patient symptoms and radiographic criteria of the spine was developed to aid in predicting spine stability of neoplastic lesions. The classification system includes global spinal location of the tumor, type and presence of pain, bone lesion quality, spinal alignment, extent of vertebral body collapse, and posterolateral spinal element involvement. Qualitative scores were assigned based on relative importance of particular factors gleaned from the literature and refined by expert consensus.
  
  
  CONCLUSIONS
  The Spine Instability Neoplastic Score is a comprehensive classification system with content validity that can guide clinicians in identifying when patients with neoplastic disease of the spine may benefit from surgical consultation. It can also aid surgeons in assessing the key components of spinal instability due to neoplasia and may become a prognostic tool for surgical decision-making when put in context with other key elements such as neurologic symptoms, extent of disease, prognosis, patient health factors, oncologic subtype, and radiosensitivity of the tumor.
authors.affiliation: Combined Neurosurgery and Orthopaedic Spine Program, Department of Orthopaedics, University of British Columbia, Vancouver, BC, Canada. charles.fisher@vch.ca
authors.forename: Charles G
authors.initials: CG
authors.lastname: Fisher
authors.forename: Christian P
authors.initials: CP
authors.lastname: DiPaola
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Ryken
authors.forename: Mark H
authors.initials: MH
authors.lastname: Bilsky
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Shaffrey
authors.forename: Sigurd H
authors.initials: SH
authors.lastname: Berven
authors.forename: James S
authors.initials: JS
authors.lastname: Harrop
authors.forename: Michael G
authors.initials: MG
authors.lastname: Fehlings
authors.forename: Stefano
authors.initials: S
authors.lastname: Boriani
authors.forename: Dean
authors.initials: D
authors.lastname: Chou
authors.forename: Meic H
authors.initials: MH
authors.lastname: Schmidt
authors.forename: David W
authors.initials: DW
authors.lastname: Polly
authors.forename: Roberto
authors.initials: R
authors.lastname: Biagini
authors.forename: Shane
authors.initials: S
authors.lastname: Burch
authors.forename: Mark B
authors.initials: MB
authors.lastname: Dekutoski
authors.forename: Aruna
authors.initials: A
authors.lastname: Ganju
authors.forename: Peter C
authors.initials: PC
authors.lastname: Gerszten
authors.forename: Ziya L
authors.initials: ZL
authors.lastname: Gokaslan
authors.forename: Michael W
authors.initials: MW
authors.lastname: Groff
authors.forename: Norbert J
authors.initials: NJ
authors.lastname: Liebsch
authors.forename: Ehud
authors.initials: E
authors.lastname: Mendel
authors.forename: Scott H
authors.initials: SH
authors.lastname: Okuno
authors.forename: Shreyaskumar
authors.initials: S
authors.lastname: Patel
authors.forename: Laurence D
authors.initials: LD
authors.lastname: Rhines
authors.forename: Peter S
authors.initials: PS
authors.lastname: Rose
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Sciubba
authors.forename: Narayan
authors.initials: N
authors.lastname: Sundaresan
authors.forename: Katsuro
authors.initials: K
authors.lastname: Tomita
authors.forename: Peter P
authors.initials: PP
authors.lastname: Varga
authors.forename: Luiz R
authors.initials: LR
authors.lastname: Vialle
authors.forename: Frank D
authors.initials: FD
authors.lastname: Vrionis
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Yamada
authors.forename: Daryl R
authors.initials: DR
authors.lastname: Fourney
mesh_terms: D026683:Advisory Committees; D000368:Aged; D032921:Consensus; D003697:Delphi Technique; D019317:Evidence-Based Medicine / Q000379:methods*; D005260:Female; D006801:Humans; D007390:International Agencies; D007593:Joint Instability / Q000145:classification* / Q000175:diagnosis / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D013125:Spinal Neoplasms / Q000150:complications* / Q000175:diagnosis / Q000556:secondary*; D011795:Surveys and Questionnaires