Diabetic Foot Ulcer-Associated Versus Other Lower-Extremity Necrotising Soft-Tissue Infections: A Retrospective Cohort Study.

To compare clinical characteristics, microbiology, treatment burden and outcomes between lower-extremity necrotising soft tissue infections associated with diabetic foot ulcers (DFU) and lower-extremity necrotising soft tissue infections not associated with DFU. We retrospectively reviewed 86 surgically treated patients at a single tertiary hospital from 2015 to 2025. Twenty patients had diabetic foot ulcer-associated infections and 66 had infections from other causes. Baseline characteristics, laboratory findings, microbiology, resource utilisation, wound healing, amputation and mortality were compared between the cohorts. The diabetic foot ulcer-associated group had a longer diabetes duration, higher glycated haemoglobin and a greater prevalence of hypertension, coronary heart disease and chronic kidney disease. Microbiological profiles showed overlapping distributions of major pathogens. The proportion of patients who were alive with a healed wound at 90 days was lower in the DFU-associated group (35.0% vs. 80.3%), and overall amputation was more frequent (55.0% vs. 15.2%), primarily driven by minor amputation (40.0% vs. 1.5%). Major amputation (15.0% vs. 13.6%) and mortality (10.0% vs. 4.5%) did not differ statistically, although estimates were imprecise. Lower-extremity necrotising soft tissue infections associated with DFU were associated with greater comorbidity, resource utilisation, minor amputation and a lower proportion of patients alive with a healed wound at 90 days. This retrospective study cannot determine whether minor amputation improves survival or prevents major amputation.