Intraosseous Versus Intravenous Vancomycin in Below-Knee Amputation for Ischemic Diabetic Foot

This randomized clinical trial compared two routes of vancomycin administration in patients undergoing below-knee amputation for ischemic diabetic foot infection. Patients with diabetic foot infection and impaired lower-extremity circulation may have reduced delivery of intravenously administered antibiotics to the amputation stump. Intraosseous administration may increase local antibiotic exposure at the surgical site while reducing systemic exposure. Participants were randomly assigned to receive either intraosseous vancomycin or intravenous vancomycin before skin incision. The study evaluated vancomycin concentrations in amputation stump subcutaneous tissue, simultaneous serum vancomycin concentrations, tissue-to-serum concentration ratios, inflammatory marker trajectories, early wound outcomes, pain scores, drain output, reintervention, mortality, renal safety, and systemic adverse events through postoperative follow-up.

Inclusion Criteria: * Age 18 years or older * Diagnosis of diabetes mellitus * Diabetic foot infection with distal ischemia * Scheduled to undergo below-knee amputation * Absence of a feasible further revascularization option, as determined by the cardiovascular surgery and interventional radiology teams * Adequate circulation at and proximal to the planned below-knee amputation level for stump healing * Ability to provide written informed consent Exclusion Criteria: * Documented allergy or hypersensitivity to vancomycin or cephalosporins * Dialysis dependence * Systemic vancomycin use within 48 hours before surgery * Previous Syme amputation or more proximal amputation * Planned amputation at a level other than below the knee * Incomplete perioperative pharmacokinetic sampling