# Comparative outcomes of gram-positive and gram-negative intraoperative infections in degenerative scoliosis: a 10-year propensity score-matched analysis

## TL;DR

This study compares outcomes of Gram-positive and Gram-negative infections after scoliosis surgery, finding that each type leads to different complications and risks.

## Contribution

The study provides new insights into the clinical implications of Gram staining in predicting postoperative infection outcomes in scoliosis patients.

## Key findings

- Gram-negative infections led to more returns to surgery and neurological deficits.
- Gram-positive infections were linked to longer infection duration and higher mortality.
- Propensity score matching revealed distinct risk profiles between the two infection types.

## Abstract

In this study, we examine the characteristics of Gram-negative and Gram-positive infections following scoliosis corrective surgery, as well as the potential risk factors contributing to infection.

We queried the Scoliosis Research Society (SRS) database from 2013 to 2023 to identify patients with degenerative scoliosis who developed postoperative infections. To account for comorbidities and minimize bias, 1:1 propensity score matching with replacement was performed. The total cohort sample was 706 (353 in each group), with 64% being female and a mean age of 67.9 years. The outcomes analyzed included infection duration, presence of neurological deficits, and mortality.

Gram-negative infections had higher rates of return to the operating room (95.2% vs 74.5%, p < 0.001), and re-insertion of instruments (10.5% vs 4.5%, p = 0.004). However, Gram-positive bacteria were associated with higher rates of antibiotic-related complications (4.3% vs 1.1%, p = 0.02).

Gram-positive infections were associated with prolonged infection courses and higher mortality, while Gram-negative infections more often resulted in a return to surgery and neurological deficits. These findings suggest that Gram staining may provide an early and clinically meaningful distinction in risk stratification for patients with postoperative wound infections following scoliosis surgery.