Beyond the Surface: Clinical Insights into Diabetic Foot Ulcer Biofilm, Chronic Inhibitory Bacterial Load, and Sharp Debridement

Background: Diabetic foot ulcers (DFUs) are frequently complicated by high bacterial burden and biofilm, yet the practical implications for sharp debridement remain uncertain. This review examined where bacterial burden and biofilm are located in DFUs, how far debridement should extend, what may remain after debridement, and how often the procedure should be repeated. Methods: PubMed, Scopus, and CENTRAL were searched, with additional targeted hand-searching, and 33 publications were included in the narrative synthesis. Results: The evidence showed that substantial bacterial burden may be present even in wounds without obvious clinical signs and may extend into the wound edge and periwound tissue. Biofilm-like structures have been demonstrated directly in DFU tissue, but direct clinical evidence of complete biofilm removal remains limited. Adequate debridement was associated with better healing, although no validated depth, fixed margin, or bleeding endpoint was identified. Studies measuring bacterial burden before and after debridement consistently suggested reduction rather than complete clearance. Evidence on frequency was less straightforward: large observational studies associated more frequent debridement with faster healing, whereas randomized evidence found no clear advantage of weekly over every-second-week debridement in selected neuropathic DFUs. Fluorescence imaging may help identify residual or clinically unsuspected bacterial burden and can alter the extent or location of debridement. Conclusions: Overall, sharp debridement remains an important part of DFU care, but the available evidence supports a flexible, wound-guided approach rather than rigid procedural rules. More work is needed to define objective endpoints for debridement adequacy, biofilm removal, and repeat treatment.