Diabetic Foot Infections Guidelines

Updated: Jan 16, 2020
  • Author: Michael Stuart Bronze, MD; Chief Editor: Romesh Khardori, MD, PhD, FACP  more...
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Guidelines

Guidelines Summary

A 2016 study by Allahabadi et al developed consensus statements on the surgical management of diabetic foot osteomyelitis. These included the following with regard to the operative management of diabetic forefoot osteomyelitis [24] :

  • Before bone is definitively resected and soft-tissue closure/reapproximation is performed over remaining bone, concomitant deep soft-tissue infection (ie, abscess, joint-space infection) or soft-tissue necrosis should be drained/debrided and controlled
  • When serial operations are performed for soft-tissue infection in patients with diabetic foot osteomyelitis, the use of negative-pressure wound therapy dressings with instillation may be considered during intervals between surgeries
  • Whenever possible, bone should be resected until grossly healthy bone is revealed (that is, bone with normal caliber, smooth cortical contour, firm density, and punctate bleeding)
  • All areas of significant cortical destruction demonstrated on plain radiography, as well as any grossly infected, necrotic, or fragmented bone, should be included in the bone resection.
  • Grossly abnormal or infected bone should be sent for microbiology
  • Analysis of operative bone specimens sent for microbiology should include microscopic examination of a Gram-stained smear, along with the assessment of aerobic and anaerobic cultures
  • Grossly abnormal or infected bone should be sent for histopathology
  • A sample of the proximal-most bone resected (ie, a bone-margin specimen) should be labeled separately and sent for histopathology
  • A sample of the proximal-most bone resected (ie, a bone-margin specimen) should be labeled separately and sent for microbiology
  • A power saw is the preferred instrument for bone transection
  • Final bone resection and attempted delayed primary skin and soft-tissue closure should be performed 3-7 days after soft-tissue infection or necrosis has been attended to and appropriate antibiotic therapy has commenced
  • Preferably, grossly normal-appearing bone margins should be obtained at the time of the final planned operative debridement
  • For selected patients with osteomyelitis, partial ostectomy of the distal metatarsal and/or proximal phalanx is an acceptable alternative to ray amputation if there is no radiographic involvement of the remaining bone, if the bone looks normal at surgery, and if abnormal biomechanics of the residual forefoot are not anticipated
  • In patients with significant ankle equinus deformity (inability to dorsiflex the ankle past neutral), adjunctive tendo-Achilles lengthening should always be considered
  • When significant forefoot biomechanical issues (eg, hallux valgus and hammertoe deformities) pose the risk of reulceration or new (transfer) ulcers, podiatric/orthopedic procedures should always be considered

IWGDF infection guidelines

In 2019, the International Working Group on the Diabetic Foot (IWGDF) published an update to its evidence-based guidelines on diabetic foot disease prevention and management. These included the following recommendations with regard to infection [14] :

  • The severity of a diabetic foot infection should be assessed via the Infectious Diseases Society of America/International Working Group on the Diabetic Foot classification scheme
  • When osteomyelitis of the foot is suspected in a patient with diabetes, a combination of the probe-to-bone test, the erythrocyte sedimentation rate (or C-reactive protein and/or procalcitonin), and plain radiographs are recommended as the initial diagnostic studies for this infection
  • When osteomyelitis of the foot is suspected in a patient with diabetes, but plain radiography and assessment of clinical and laboratory findings have not led to a conclusive diagnosis of osteomyelitis, an advanced imaging study, such as magnetic resonance imaging (MRI), 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) scanning, or leukocyte scintigraphy (with or without CT scanning), can be considered
  • Using curettage or biopsy, a tissue specimen for culture should be aseptically collected from the ulcer in patients with a soft tissue diabetic foot infection
  • A patient with a diabetic foot infection should be treated with an antibiotic agent whose efficacy has been demonstrated in a published randomized, controlled trial and that is appropriate for the specific individual; among the agents to consider are penicillins, cephalosporins, carbapenems, metronidazole (in combination with one or more other antibiotics), clindamycin, linezolid, daptomycin, fluoroquinolones, and vancomycin; tigecycline should not be considered
  • Factors that should be taken into account in the selection of an antibiotic agent for the treatment of a diabetic foot infection include the following: the likely or proven causative pathogen(s) and their antibiotic susceptibilities; the infection’s clinical severity; published evidence of the agent’s efficacy against diabetic foot infections; risk of collateral damage to the commensal flora and other adverse events; drug interaction risk; agent availability; and cost
  • Patients with a skin or soft tissue diabetic foot infection should undergo 1-2 weeks of antibiotic therapy
  • When no other indication for surgery exists, consider managing a patient with diabetes and uncomplicated forefoot osteomyelitis via antibiotic therapy, with no bone resection
  • Urgent evaluation is necessary with regard to the need for surgery, as well as intensive postoperative medical and surgical follow-up, when probable diabetic foot osteomyelitis exists with concomitant soft tissue infection
  • Patients with diabetic foot osteomyelitis should undergo antibiotic therapy for no more than 6 weeks; failure to see clinical improvement of the infection within the first 2-4 weeks should prompt reconsideration of bone specimen collection (for culture), surgical resection, or selection of an alternative antibiotic regimen
  • If one or more pathogens grow from an aseptically collected culture specimen obtained during bone resection surgery for diabetic foot osteomyelitis, or if osteomyelitis is revealed histologically, appropriate antibiotic treatment should be administered for up to 6 weeks