Incidence and Independent Risk Factors of Spinal Infection After Vertebral Augmentation:A Multicenter Propensity-Matched Case-Control Study

Objective: This study aimed to determine the incidence of spinal infection after vertebral augmentation (SIAVA) and identify its independent risk factors.Methods: This multicenter, retrospective case-control study included patients who underwent percutaneous vertebral augmentation (PVA) for osteoporotic vertebral compression fractures at 4 centers between January 2015 and December 2021. Each SIAVA case was matched with 3 controls using propensity score matching based on demographic and clinical variables. LASSO (least absolute shrinkage and selection operator) regression was used for variable selection, followed by multivariable conditional logistic regression to identify risk factors for SIAVA.Results: Among 7,797 PVA procedures, 42 SIAVA cases were identified, yielding an incidence of 0.54%. The median time from PVA to SIAVA diagnosis was 4.3 (interquartile range, 2.8–11.7) weeks. After 1:3 matching (42 cases vs. 126 controls), multivariable analysis identified 4 independent risk factors: preoperative pulmonary infection (odds ratio [OR], 3.64; 95% confidence interval [CI], 1.21–11.0; p=0.022), intravertebral fluid sign on magnetic resonance imaging (MRI) (OR, 6.17; 95% CI, 1.92–19.9; p=0.002), type D (intradiscal) cement leakage (OR, 2.93; 95% CI, 1.10–7.85; p=0.032), and serum albumin ≤35 g/L (OR, 3.29; 95% CI, 1.15–9.45; p=0.027). Within the infection cohort, 25 patients (59.5%) underwent revision surgery, and 2 deaths (4.8%) occurred during follow-up.Conclusion: The incidence of SIAVA was 0.54%. Preoperative pulmonary infection, intravertebral fluid sign on MRI, type D cement leakage, and serum albumin ≤35 g/L were identified as independent risk factors. These findings may help clinicians implement preoperative risk-reduction strategies.