Spinal Instability Neoplastic Index

If you or somebody you know has a spinal tumor consider the following information.

This information is taken directly from a report published in the Journal of Clinical Oncology, Volume 29 Number 22 August 1, 2011 page 3072-3077.  Every credit goes to the authors, the lead of which is Daryl R. Fourney, M.D.

The Spine Oncology Study Group (SOSG) defines spine instability as the “loss of spinal integrity as a result of a neoplastic process that is associated with movement-related pain, symptomatic or progressive deformity and/or neural compromise under physiologic loads.”

The SOSG used an evidence-based process was used to develop a scoring system, the Spine Instability Neoplastic Score (SINS), to help determine whether a metastatic lesion should be considered for surgery.  In this classification system six individual component scores are added together to give a predictive value to tumor-related instability:

Spine location

Junctional (occiput-C2, C7-T2, T11-L1, L5-S1)                     3

Mobile (C3-C6, L2-L4)                                                          2

Semirigid (T3-T10)                                                               1

Rigid (S2-S5)                                                                        0


Yes                                                                                     3

Occasional pain but not mechanical                                 1

No                                                                                      0

Lesion bone quality

Lytic                                                                                      2

Mixed (lytic/blastic)                                                              1

Blastic                                                                                   0

Radiographic alignment

Subluxation/translation present                                        4

De novo deformity (kyphosis/scoliosis)                              2

Normal alignment                                                              0

Vertebral body collapse

>50% collapse                                                                  3

<50% collapse                                                                  2

No collapse with > 50% body involved                            1

None of the above                                                            0

Posterolateral involvement of the spinal elements

Bilateral                                                                            3

Unilateral                                                                          1

None of the above                                                            0

A score of 0 to 6 denotes stability, 7 to 12 denotes indeterminate instability, and 13 to 18 denotes instability. A surgical consultation is recommended for patients with SINS scores greater 7.