Risk Factors Associated with Failure of Toe Amputation in Diabetic Foot Infections

We aim to identify the factors associated with the failure of amputation of one to three toes (index toe amputation) in patients with diabetes and foot infection. We conducted a retrospective cohort of 175 patients with diabetes who were hospitalized for moderate to severe foot infection and underwent amputation of one to three toes. A Poisson regression model was used to determine the prevalence ratio (PR) as a measure of association. The mean age was 63.3 +/- 11.4 years. Fifty-three patients presented failure after undergoing toe amputation (30.3%). Multivariate analysis, adjusted for age and sex, showed the following significant variables: severe infection (PR: 1.78; 95% confidence interval [CI]: 1.14-2.78; P = 0.011), infection by Escherichia coli (PR: 2.21; 95% CI: 1.42-3.43; P < 0.001), infection by Pseudomonas aeruginosa (PR: 2.11; 95% CI: 1.29-3.43; P = 0.003) and prothrombin time (PR: 1.13; 95% CI: 1.05-1.21; P = 0.001), obesity (PR: 0.58; 95% CI: 0.37-0.93; P = 0.024), and haemoglobin value (PR: 0.92; 95% CI: 0.86-0.99; P = 0.023). About one-third of patients who underwent amputation of one to three toes for diabetic foot infection presented a failure and required a more proximal surgery. Severe infections, isolation of Pseudomonas aeruginosa and Escherichia coli, and prolonged prothrombin time were associated with a higher prevalence of failure. However, obesity and an elevated haemoglobin level were associated with a lower prevalence of failure.