A novel classification system for spinal instability in neoplastic disease: an evidence-based approach and expert consensus from the Spine Oncology Study Group.
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.
Fisher
Charles G
CG
Combined Neurosurgery and Orthopaedic Spine Program, Department of Orthopaedics, University of British Columbia, Vancouver, BC, Canada. charles.fisher@vch.ca
DiPaola
Christian P
CP
Ryken
Timothy C
TC
Bilsky
Mark H
MH
Shaffrey
Christopher I
CI
Berven
Sigurd H
SH
Harrop
James S
JS
Fehlings
Michael G
MG
Boriani
Stefano
S
Chou
Dean
D
Schmidt
Meic H
MH
Polly
David W
DW
Biagini
Roberto
R
Burch
Shane
S
Dekutoski
Mark B
MB
Ganju
Aruna
A
Gerszten
Peter C
PC
Gokaslan
Ziya L
ZL
Groff
Michael W
MW
Liebsch
Norbert J
NJ
Mendel
Ehud
E
Okuno
Scott H
SH
Patel
Shreyaskumar
S
Rhines
Laurence D
LD
Rose
Peter S
PS
Sciubba
Daniel M
DM
Sundaresan
Narayan
N
Tomita
Katsuro
K
Varga
Peter P
PP
Vialle
Luiz R
LR
Vrionis
Frank D
FD
Yamada
Yoshiya
Y
Fourney
Daryl R
DR
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