Bone carriers in diabetic foot osteomyelitis

Abstract

Abstract Diabetes is one of the most common chronic disease worldwide, and its prevalence is rapidly increasing. Foot ulcers are a frequent complication in diabetic patients, leading to an increased risk for minor and major leg amputation and, as a consequence, to a dramatic lost in the life expectancy. Ischemia and infections are the most frequent causes of amputation, being infections the most frequent diabetic complication requiring hospitalization and the most common precipitating event leading to amputations. Diabetic foot osteomyelitis (DFO) is very difficult-to-treat situation in these patients, and failure is associated with high rates of amputations. The treatment of DFO is both medical (long-time antibiotic therapy guided by bone culture) and/or surgical (resection of infected bones), but despite the seriousness of this complication there are no agreed-upon guidelines for its management. Moreover, the impaired blood perfusion, the presence of biofilm, and the intolerance or adverse events in friable patients like diabetics can impair the effectiveness of systemic antibiotics, while the risk for biomechanical changes and for recurrent ulcerations by pressure transfer to other foot locations is consistent after the removal of infected bone. Local antibiotic delivery can yield very high concentrations exclusively in targeted areas, which cannot be achieved by systemic therapy, and this is likely to be particularly useful in poorly perfused tissues and in presence of biofilms; the limited systemic absorption reduces the risk for renal and liver toxicity avoiding drug reactions and reducing resistant microorganisms. In recent years, there has been a significant expansion in the number of local antibiotic delivery systems; nonbiodegradable vehicles (such as polymethyl methacrylate) were the first to be used, while lately there has been a shift toward biodegradable vehicles (such as calcium sulfate beads), as these do not require surgical removal and potentially offer a more prolonged elusion profile. Limited data exist in the treatment of DFO, and a robust body of evidence is still missing. The available data mainly refer to some case reports, case series, some randomized controlled trial, and some retrospective study. In summary, local delivery of antibiotics appears to be a promising option and an effective adjuvant treatment in cases of surgically treated osteomyelitis, and there also appears to be potential for soft tissue infection management in cases of infected deep ulceration.