A new study published in The International Journal of Lower Extremity Wounds by our long time friends and colleagues in Spain offers a cautionary reminder: not all positive cultures mean bone infection.
In a cohort of 93 patients undergoing conservative surgery for diabetic foot osteomyelitis, researchers compared microbiological cultures from bone resection margins with histopathology—the gold standard. Their findings were striking: nearly one in four culture-positive results were actually false positives, with no histological evidence of infection.
Even more telling, Pseudomonas aeruginosa was the only organism significantly associated with these false positives (p= .008), raising the question of species-specific behavior in contamination dynamics.
What does this mean for clinicians? While cultures are helpful in guiding antibiotic therapy, they should not be solely relied upon to determine whether osteomyelitis has been completely resected. Histopathology, despite being slower and more resource-intensive, remains the more reliable diagnostic tool.
The implications are clear: enhanced intraoperative protocols and biofilm-aware strategies may be necessary to reduce sample contamination. Until then, cultures alone may lead us astray—potentially prompting overtreatment or delayed healing.
📄 Citation: Víquez-Molina G, Rojas-Bonilla JM, Aragón-Sánchez J. Histopathology Is More Reliable Than Microbiology for Detecting Residual Osteomyelitis After Conservative Surgery for Diabetic Foot: The Pitfall of False-Positive Cultures and the Role of Pseudomonas aeruginosa. Int J Low Extrem Wounds. 2025 Apr 29. doi: 10.1177/15347346251338689
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