THE SPREAD OF FOOT INFECTION AND ITS IMPACT ON THE OUTCOMES OF MAJOR AMPUTATIONS OF LOWER EXTREMITIES IN DIABETIC PATIENTS

Abstract

Aim To assess the spread of foot infection and its impact on the outcomes of major amputations of lower extremities in diabetic patients. Method In a multicentre retrospective and prospective cohort study, we included adult diabetic patients (≥ 18 years) who underwent a major amputation of a lower limb in 5 hospitals between 2000 and 2009, 2012 and 2014. A total of 51 patients were included (of which 27 (52.94%) were men and 24 (47.06%) were women) with the mean age of 65.51 years (SD=16.99). Concomitant section9s osseous slice biopsy (BA) and percutaneous bone biopsy of the distal site (BD) were performed during limb amputation. A new surgical set-up and new instruments were used to try and reduce the likelihood of cross-contamination during surgery. A positive culture was defined as the identification of at least 1 species of bacteria not belonging to the skin flora or at least 2 bacteria belonging to the skin flora (CoNS (coagulase negative staphylococci), Corynebacterium spp, Propionibacterium acnes ) with the same antibiotic susceptibility profiles. A doubtful culture was defined as the identification of 1 species of bacteria belonging to the skin flora. The patients were followed-up for 1 year. Stump outcomes were assessed on the delay of complete healing, equipment, need of re-intervention and antibiotics. Results In total, 51 BA were performed during major lower limb amputations (17 above the knee and 34 below the knee) in diabetic patients. Nine (17.65%) bacterial culture results from BA specimens were positive, 7 (13.73%) doubtful and 35 (68.63%) sterile. Before amputation, 23 patients (45.1%) had not received any antibiotics, including 16 (31.37%) with an antibiotic-free interval of 15 days or more. Microorganisms identified in BA were also cultured from the distal site in 33.33% of the cases. Positive BA was associated with prolonged complete stump healing, delay of complete healing (more than 6 months), re-amputation and the need of antibiotics Conclusions The microorganisms identified from BA play a role in stump healing in diabetic patients. BA is useful during major limb amputation due to infectious complications and antibiotic therapy could be corrected on the basis of the BA culture results.