Impact of Spinal Instrumentation on Neurological Outcome in Patients with Intermediate Spinal Instability Neoplastic Score (SINS)

Abstract

Background: Adequate assessment of spinal instability using the spinal instability neoplastic score (SINS) frequently guides surgical therapy in spinal epidural osseous metastases and subsequently influences neurological outcome. However, how to surgically manage ‘impending instability’ at SINS 7–12 most appropriately remains uncertain. This study aimed to evaluate the necessity of spinal instrumentation in patients with SINS 7–12 with regards to neurological outcome. Methods: We screened 683 patients with spinal epidural metastases treated at our interdisciplinary spine center. The preoperative SINS was assessed to determine spinal instability and neurological status was defined using the Frankel score. Patients were dichotomized according to being treated by instrumentation surgery and neurological outcomes were compared. Additionally, a subgroup analysis of groups with SINS of 7–9 and 10–12 was performed. Results: Of 331 patients with a SINS of 7–12, 76.1% underwent spinal instrumentation. Neurological outcome did not differ significantly between instrumented and non-instrumented patients (p = 0.612). Spinal instrumentation was performed more frequently in SINS 10–12 than in SINS 7–9 (p < 0.001). The subgroup analysis showed no significant differences in neurological outcome between instrumented and non-instrumented patients in either SINS 7–9 (p = 0.278) or SINS 10–12 (p = 0.577). Complications occurred more frequently in instrumented than in non-instrumented patients (p = 0.016). Conclusions: Our data suggest that a SINS of 7–12 alone might not warrant the increased surgical risks of additional spinal instrumentation.

Prognosis after Palliative Surgery for Patients with Spinal Metastasis: Comparison of Predicted and Actual Survival

“…The current study did not show any association of SINS or surgical procedures with the survival period. SINS is an important scoring system to assess spinal instability and determine the need for fusion surgery [ 29 ]; however, it may not predict the survival after palliative surgery based on the results of the current study.…”

Trends in the surgical treatment for metastatic spinal tumor in Japanese administrative data between 2012 and 2020

“…[27] Although the optimal cutoff value for the need for fusion surgery has not been reached consensus, it is generally divided into 3 categories: stable (0-6 points), impending/potentially unstable (7-12 points), and unstable (13-18 points). With the worldwide recognition of SINS, spine surgeons or oncologists become to determine the application of fusion procedures by the score of SINS [28,29].…”

An Updated Review on the Treatment Strategy for Spinal Metastasis from the Spine Surgeon’s Perspective

“…For patients with impending instability (intermediate SINS score of 7-12), the decision of performing surgical stabilization is often difficult. Lenschow et al [57] reviewed 331 spinal metastasis patients with intermediate SINS and found no significant differences in neurological outcomes between instrumented and noninstrumented patients. However, an increase in surgical complications was noted in the instrumented group [57].…”

“…Lenschow et al [57] reviewed 331 spinal metastasis patients with intermediate SINS and found no significant differences in neurological outcomes between instrumented and noninstrumented patients. However, an increase in surgical complications was noted in the instrumented group [57]. Kim et al [58] suggested that surgical stabilization should be performed in patients having >50% vertebral body collapse with intermediate SINS.…”