Metastatic spinal tumor frailty index and New England spinal metastasis score show the most consistent performance for short-term postoperative outcomes: Single-center validation in 114 patients

Background Frailty indices are established tools for estimating long-term survival in oncology, yet their utility for predicting short-term surgical outcomes remains less defined. This study evaluates several frailty, comorbidity, and risk indices for predicting postoperative care needs and other short-term outcomes in patients undergoing spinal metastasis resection.Methods A retrospective cohort study was performed on patients undergoing surgery for spinal metastasis at a tertiary spine center. Preoperative risk was assessed using the modified 5-item frailty index (mFI-5), Metastatic Spinal Tumor Frailty Index (MSTFI), modified Charlson Comorbidity Index (CCI), New England Spinal Metastasis Score (NESMS), modified Bauer score (mBauer), and Spinal Instability Neoplastic Score (SINS). Multivariate logistic regression evaluated associations between indices and nonroutine discharge, prolonged length of stay (LOS), and reoperation, as well as other secondary outcomes.Results Among 114 patients (mean age 65.6±10.7 years; 57.9% male), 57.0% were discharged to nonroutine settings, 16.7% underwent reoperation, and the mean length of stay was 11.1±10.8 days. MSTFI was independently associated with nonroutine discharge (OR=2.81, 95% CI [1.64-4.84], pConclusions In this single-center surgical cohort, MSTFI and NESMS were the most consistent risk-stratification tools for short-term outcomes, particularly discharge disposition and LOS. Secondary analyses suggested additional associations of NESMS with spine-related complications and 90-day mortality, whereas no index reliably predicted reoperation. Incorporating MSTFI and/or NESMS into preoperative assessment may improve risk stratification and perioperative planning.