Cross-sectional Analysis of Risk Factors for Surgical Site Infection Secondary to Spinal Internal Fixation via the Posterior Approach

Backgroud: The aim of this study was to investigate the risk factors related to surgical site infection (SSI) secondary to spinal internal fixation via the posterior approach.Methods: Patients who had undergone spinal internal fixation via the posterior approach at the spinal center of our hospital from January 2004 to December 2019 were selected in this cross-sectional study. Information about age, sex, body mass index (BMI), fused segment, hemoglobin concentration, serum albumin concentration, surgical duration, surgery beginning time, allogeneic blood transfusion, combined diabetes, peak blood glucose 72 h postoperatively ≥12 mmol/L, smoking history, and blood loss were included. The factors related to SSI were analyzed using univariate and multivariate analyses. P < 0.05 was considered to indicate statistical significance.Results: Among the 4,350 patients, 66 had SSI, with an infection prevalence of 1.5%. The subjects included 37 men and 29 women (age range, 22–84 y; average age, 47.4 ± 12.8 y). Univariate analysis showed that sex, BMI, fused segment, surgery beginning time, allogeneic blood transfusion, and smoking history were not correlated to infection (P > 0.05). However, age >60 y, surgical duration >3 h, serum albumin concentration <30 g/L, hemoglobin concentration <80 g/L, combined diabetes, peak blood glucose 72 h postoperatively ≥12 mmol/L, and blood loss >1,000 mL were correlated with infection (P < 0.05). Multivariate logistic regression analysis demonstrated that age >60 y, surgical duration >3 h, hemoglobin concentration <80 g/L, serum albumin concentration <30 g/L, combined diabetes, and blood loss >1,000 mL were significantly correlated with SSI secondary to spinal internal fixation via the posterior approach.Conclusion: This study provides information on SSI secondary to spinal internal fixation via the posterior approach. We found that age >60 y, surgical duration >3 h, hemoglobin concentration <80 g/L, serum albumin concentration <30 g/L, combined diabetes, and blood loss >1,000 mL are directly correlated with SSI secondary to spinal internal fixation via the posterior approach. These findings may contribute to discussions and actions that may help to reduce SSI secondary to spinal internal fixation via the posterior approach in the short or medium term.