Optimal Antibiotics for Operated Diabetic Foot Infections

Diabetic foot problems, especially infections (DFI), require multiple resources including iterative surgeries and amputations, long-lasting antibiotic therapies, education, off-loading and eventually revascularization and appropriate foot-ware. Treatment is complicated, multidisciplinary, and marked with a high risk of recurrences. This is a retrospective and prospective cohort with side studies of pathologies and academic research questions that cannot be separated from each other. The investigators establish a retro-and prospective cohort of diabetic foot problems (ambulatory and hospitalized patients) and perform side studies to reduce the incidence of complications, and to reduce recurrences of DFI, cost and adverse events related to therapies. Cohort: Prospective and retrospective cohort of all diabetic foot problems with emphasis on surgical and infectious variables. Trial 1 (Randomized trial on residual infection after amputation): Determination of the level of amputation per MRI followed by a randomization concerning the duration of post-amputation systemic antibiotic therapy, if there is residual bone infection. Trial 2 (Randomized trial on infection without amputation): Determination of the duration of systemic antibiotic therapy in diabetic foot infections without Amputation of the infection.

Trial 1: At enrollment (Day 1), the investigator will prescribe empiric antibiotic treatment based on instructions provided in the protocol and determine the most appropriate route of administration (oral or IV) according to the patient's condition. Patients will be randomized in the ratio 1:1 between 1 versus 4 days for post-amputation soft tissue infections; and between 1 versus 3 weeks if there is microbiologically proven residual bone infection/contamination in the proximal stump samples of the residual bone. Trial 2: At enrollment (Day 1), the investigator will prescribe empiric antibiotic treatment based on instructions provided in the protocol and determine the most appropriate route of administration (oral or IV) according to the patient's condition. Patients will be randomized in the ratio 1:1 between 10 versus 20 days for post-debridement soft tissue infections; and between 3 versus 6 weeks for diabetic foot osteomyelitis post.-debridement (without amputation).

The intervention group consists of 1 day of postoperative antibiotic therapy for eventual residual soft tissue infection after amputation.

The control group consists of 4 days duration of postoperative antibiotic therapy for eventual residual soft tissue infection after amputation.

The intervention group consists of 1 week of postoperative antibiotic therapy for eventual residual bone infection / contamination in the proximal bone stump after amputation.

The intervention group consists of 3 weeks of postoperative antibiotic therapy for eventual residual bone infection / contamination in the proximal bone stump after amputation.

The intervention group consists of 10 days of post-debridement antibiotic therapy for non-amputated diabetic foot soft tissue infection.

The control group consists of 20 days of post-debridement antibiotic therapy for non-amputated diabetic foot soft tissue infection.

The intervention group consists of 3 weeks of post-debridement antibiotic therapy for non-amputated diabetic foot osteomyelitis.

The control group consists of 6 weeks of post-debridement antibiotic therapy for non-amputated diabetic foot osteomyelitis.

Number of Participants with a clinical and microbiological remission of treated infection at 2 months

Evaluation of the accuracy of the extension of infection. Surgical decision for amputation level per magnetic resonance imaging when compared to microbiology, histology and intraoperative assessment.

Questionnaires and Scores (e.g. AOFAS Score) ranging from 0 to 1. Alternatively, a home made Likert Scale ranging from 0 to 7 Points will be used.

Inclusion Criteria: Age ≥ 18 years Diabetic foot infections or ischemia/necrosis with surgical amputation/disarticulation level in vicinity of MRI signs of infection At least two months of follow-up from hospitalization Patient signing to participate, including acceptance of local wound care, -off-loading and arterial re-vascularization (if clinically indicated). Exclusion Criteria: At least 5 cm of distance between amputation level and infection. Any concomitant infection requiring more than 5 days of systemic antibiotic therapy Eventual osteosynthesis material not removed

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Waibel F, Berli M, Catanzaro S, Sairanen K, Schoni M, Boni T, Burkhard J, Holy D, Huber T, Bertram M, Laubli K, Frustaci D, Rosskopf A, Botter S, Uckay I. Optimization of the antibiotic management of diabetic foot infections: protocol for two randomized controlled trials. Trials. 2020 Jan 8;21(1):54. doi: 10.1186/s13063-019-4006-z.