Treating Diabetic Foot Osteomyelitis: A Practical State-of-the-Art Update

Abstract

Background and Objectives: Diabetic foot osteomyelitis (DFO) can be difficult to treat and securing optimal clinical outcomes requires a multidisciplinary approach involving a wide variety of medical, surgical and other health care professionals, as well as the patient. Results of studies conducted in the past few years have allowed experts to formulate guidelines that can improve clinical outcomes. Material and Methods: We conducted a narrative review of the literature on treat- ment of DFO, with an emphasis on studies published in the last two years, especially regarding antimicrobial therapies and surgical approached to treatment of DFO, supplemented by our own extensive clinical and research experience in this field. Results: Major amputations were once com- mon for DFO but, with improved diagnostic and surgical techniques, "conservative" surgery (foot- sparing, resecting only the infected and necrotic bone) is becoming commonplace, especially for forefoot infections. Traditional antibiotic therapy, which has been administered predominantly in- travenously and frequently for several months, can often be replaced by appropriately selected oral antibiotic regimens following only a brief (or even no) parenteral therapy, and given for no more than 6 weeks. Based on ongoing studies, the recommended duration of treatment may soon be even shorter, especially for cases in which a substantial portion of the infected bone has been resected. Using the results of cultures (preferably of bone specimens) and antimicrobial stewardship princi- ples allows clinicians to select evidence-based antibiotic regimens, often of a limited pathogen spec- trum. Intra-osseous antimicrobial and surgical approaches to treatment are also evolving in light of ongoing research. Conclusions: In this narrative, evidenced-based review, taking consideration of principles of antimicrobial stewardship and good surgical practice, we have highlighted the recent literature and offered practical, state-of-the-art advice on the antibiotic and surgical management of DFO.

Keywords: amputations; antibiotic stewardship; antibiotic therapy; clinical outcomes; clinical research; diabetic foot osteomyelitis; foot surgery.

Figure 1

Infected ulceration of the lateral edge of the right foot in a man with diabetic Charcot neuro-osteoarthropathy (with previous amputations of both great toes). Note the collapse of the midfoot, with consequent pressure-related ulcerations, a long-standing clinical problem. The ulcer on the lateral foot recently became infected and was found to have underlying bone involvement. As shown in this photograph, the manifestations of infection in a diabetic foot ulcer may be minimal at the beginning, but can progress rapidly. There is somewhat more pronounced erythema and induration proximal and dorsal to the ulcer. The patient noticed new pain at the site and a sudden change in the color of the foot. He had no fever or visible purulent secretions. This case illustrates that: infection in the diabetic foot is almost always due to underlying problems (such as foot deformity or peripheral neuropathy); even deep infection may present with initially relatively minimal signs and symptoms; clinician’s should consider osteomyelitis in every diabetic patient with a foot ulceration. (Photograph obtained with permission of the patient).

Figure 2

Amputation of the hallux (including the sesamoid bones) in a middle-aged woman for diabetic foot osteomyelitis developing in the setting of a long-standing, neglected plantar ulcer. The infection in the bone was chronic, but was recently complicated by an acute flare of soft tissue infection; this could be a spread from the underlying bone or a new infectious episode caused by a new pathogen. After discussion with the patient, we decided to remove the ulcer along with the underlying infected bone; we debrided the soft tissues, but left the majority of the infected soft tissue, which was treated with systemic antibiotic therapy. In this photograph, taken the first postoperative day, note the substantial residual soft tissue infection, along with a small postoperative hematoma in the forefoot. (Photograph obtained with permission of the patient).