# Prevalence and Risk Factors of Postoperative Spinal Infections: A Five-year Study in Northwestern Iran

## TL;DR

This study found a 6% infection rate after spinal surgery in northwestern Iran and identified risk factors like diabetes and long surgery times.

## Contribution

The study identifies specific risk factors for postoperative spinal infections in a regional population in Iran.

## Key findings

- Postoperative spinal infections occurred in 6% of patients.
- Staphylococcus aureus was the most common pathogen.
- Diabetes and prolonged surgery duration were the strongest risk factors.

## Abstract

Surgical site infections (SSIs), particularly after spinal procedures, remain a major concern despite advances in infection control. This study aimed to determine the prevalence and associated risk factors of postoperative spinal infections in northwestern Iran.

A cross-sectional study was conducted on 500 adult patients (≥18 years) who underwent spinal surgery in two referral hospitals in Tabriz (Imam Reza and Shohada) between March 2019 and February 2024. Postoperative infections were confirmed by infectious disease specialists. Data on demographics and surgical variables (including surgical site, approach, duration, blood loss, and transfusion) were collected using a standardized checklist. Statistical analyses were conducted in SPSS version 23.0 using Chi-squared and independent samples t-tests. Logistic regression was performed to estimate adjusted odds ratios (ORs) with 95% confidence intervals (CIs).

The prevalence of postoperative spinal infections was 6%. Staphylococcus aureus was the most common pathogen (66.7%). Significant risk factors included female sex, older age, corticosteroid use, diabetes mellitus, longer surgery duration (>4 hours), blood loss (>1 liter), and blood transfusion (P<0.05). Diabetes (OR=5.90, 95% CI: 2.30–15.20) and prolonged surgery (OR=6.90, 95% CI: 2.50–19.00) showed the strongest associations. No significant associations were found for BMI, smoking, hypertension, CRP, ESR, surgical site, or technique.

A 6% infection rate was identified, with several clinical and demographic factors increasing risk. Recognizing these predictors is essential for prevention. Broader, multi-center studies are recommended to validate findings and inform national surgical infection control policies.