A Comparison of Demographic and Microorganism Differences Between De Novo and Postoperative Infections.

STUDY

DESIGN

Retrospective cohort.

OBJECTIVES

To compare demographic and microorganism culture data between primary and postoperative infections.

BACKGROUND

Current literature suggests that both de novo and postoperative infection rates are increasing. At present, there is a paucity of research directly comparing de novo and postoperative spinal infections.

METHODS

Patients aged 18 years or older who underwent an irrigation and debridement (I&D) for de novo spine infections and infections following elective spine surgeries from 2017 to 2023 were compared. All patients were retrospectively reviewed for demographic information, comorbidities, and social history. Tissue microbiology of both cohorts was compared by broad classes (eg, gram-positive vs gram-negative, aerobic vs anaerobic, monomicrobial vs polymicrobial) and individual microbes (eg, Staphylococcus aureus, E. Coli, Pseudomonas, etc). Statistical analysis was performed, and P-value <0.05 was considered statistically significant.

RESULTS

One hundred fifty-three patients underwent an I&D in the setting of a de novo spine infection, while 239 patients underwent an I&D in the setting of a postoperative infection. Patients who developed de novo infections were on average younger (P = 0.002) with lower BMIs (P < 0.001) and were more likely to be current smokers (P = 0.005). These patients also had higher rates of hepatitis C (P < 0.001), CKD (P = 0.009), and prior IV drug use (P < 0.001). De novo infections had higher rates of gram-positive (P = 0.004), monomicrobial (P = 0.013), and aerobic (P = 0.026) infections than postoperative infections. Staphylococcusaureus infection rates were statistically similar between groups (P = 0.138), while Streptococcus was more common in the postoperative infection cohort (P = 0.002). Pseudomonas, proteus, and Corynebacterium were identified significantly more often in the postoperative infection cohort.

CONCLUSIONS

Patients developing de novo and postoperative spine infections exhibit notable demographic and microorganism differences. Adequate treatment of patients with spinal infections, therefore, requires an awareness of both medical and social factors most prevalent within these two populations.