Spine Surgeon NYU School of Medicine New Canaan, CT, US
Introduction: The comparison of various frailty indices and their ability to predict complications after adult spinal deformity(ASD) surgery has not been investigated. We sought to determine if certain frailty indices have better predictability of complication rates following ASD surgery.
Methods: ASD patients with 2-year (2Y) data were included. Four frailty indices were used for comparison: Passias et al modified ASD frailty index(mFI), Miller et al ASD frailty index(FI-ASD), the ACS-NSQIP 5-Factor frailty index(ACS-FI5), and the FRAIL Scale(PMID: 29792992). Patients were stratified into not frail(NF), frail(F), and severely frail(SF). Associations of indices with EBL, operative time, complications, hospital-acquired conditions(HAC: UTI,DVT/PE,SSI), reoperations, SICU stay, and LOS were compared using ANOVA, logistic and linear regression.
Results: 421 ASD patients were included(Age: 60.4,BMI: 28.0,CCI: 1.9). Total complication rates: 71% any comp, 27% major (68% surgical,32% medical), 35% minor, 25% intraoperative, 18% mechanical, 22% underwent reoperation. Severely frail patients were much more likely to present with a severe ODI(OR: 16,[7.2-29.8]). All four indices significantly correlated with intraop details and complications. All four indices correlated to SICU time and total LOS. Only FRAIL Scale correlated with SICU admission rate(OR: 1.2,[1.03-8.8]), while no index was predictive of complicationss prior to discharge(all p>.05). ASD-FI had the strongest correlation with perioperative complications, including HACs(OR: 1.2,[1.1-6.3]) and major complications(OR: 1.5,[1.1-4.7]). Logistic regression analysis demonstrated mFI was the only correlate for all 2Y complications, along with highest OR for predicting mechanical complications(OR: 1.6,[1.3-1.9]). ASD-FI SF group had the greatest improvement(ODI,SRS-Total), while mFI SF had lowest rates of improvement. Given their higher complication rates, this translated to higher cost-per-QALY for SF patients when stratified by mFI(p < .001).
Conclusion : Frailty imposes a significant burden on adult spinal deformity patients from presentation through cost-utility at two years. These findings highlight the impact of frailty stratification during surgical planning to effectively assess the risk of patients undergoing corrective surgery.
