Is frailty responsive to surgical correction of adult spinal deformity? An investigation of sagittal re-alignment and frailty component drivers of postoperative frailty status.

ABSTRACT

PURPOSE: Frailty has been associated with adverse postoperative outcomes. Recently, a novel frailty index for preoperative risk stratification in patients with adult spinal deformity was developed. Components of the ASD-FI utilize patient comorbidity, clinical symptoms, and patient-reported-outcome-measures (PROMS). Our purpose was to investigate components of the Adult Spinal Deformity Frailty Index (ASD-FI) responsive to surgery and drivers of overall frailty. METHODS: Operative ASD patients ≥ 18 years, undergoing multilevel fusions, with complete baseline, 6 W, 1Y and 2Y ASD-FI scores. Descriptive analysis assessed demographics, radiographic parameters, and surgical details. Pearson bivariate correlations, independent and paired t tests assessed postoperative changes to ASD-FI components, total score, and radiographic parameters. Linear regression models determined the effect of successful surgery (achieving lowest level SRS-Schwab classification modifiers) on change in ASD-FI total scores. RESULTS: 409 6-week, 696 1-year, and 253 2-year operative ASD patients were included. 6-week and 1-year baseline frailty scores were 0.34, 2 years was 0.38. Following surgery, 6-week frailty was 0.36 (p = 0.033), 1 year was 0.25 (p < 0.001), and 2 years was 0.28 (p < 0.001). Of the ASD-FI variables, 17/40 improved at 6 weeks, 21/40 at 1 year, and 18/40 at 2 years. Successful surgery significantly predicted decreases in 1-year frailty scores (R = 0.27, p < 0.001), SRS-Schwab SVA modifier was the greatest predictor (Adjusted Beta - 0.29, p < 0.001). CONCLUSIONS: Improvement in sagittal realignment and functional status correlated with improved postoperative frailty. Additional research and deformity sub-group analyses are needed to describe associations between specific functional activities that correlated with frailty improvement as well as evaluation of modifiable and non-modifiable indices.