Antibiotics First Choice for Diabetic Foot Osteomyelitis

October 24, 2013

The first-ever study to compare the use of antibiotics with surgery for the treatment of diabetic foot osteomyelitis has found that the 2 approaches provide similar outcomes in terms of healing rates, time to healing, and short-term complications.

The findings, which are published online October 15 in Diabetes Care, therefore point to antibiotic therapy being the logical first choice for the patient population in this trial, those with diabetic foot osteomyelitis and ulcers in the forefoot, lead author José Luis Lázaro-Marinez, PhD, from Unidad de Pie Diabético, Madrid, Spain, told Medscape Medical News.

Specifically, "if a person has a soft-tissue infection associated with osteomyelitis, a good vascular supply, and you cannot see the bone [through the ulcer], then the best option is 90 days of antibiotics," he said. "After this period, if things don't improve, you can consider surgery as a second option."

Asked to comment on the findings, Andrew Boulton, MD, from the University of Manchester, United Kingdom, said: "This is a very interesting study and shows that for many cases of osteomyelitis, surgery is not needed."

The results build on a number of prior case series suggesting that antibiotics alone work, he noted.

"Indeed, I have a lot of experience with this, and we have had a large number of patients with osteomyelitis particularly confined to one digit, which can be treated with long-term antibiotics (up to 3 months of drugs such as clindamycin)," he told Medscape Medical News. "We have on numerous occasions seen radiological healing and resolution of previous changes in patients treated on antibiotics alone, so this is an important addition to the literature."

Debate on Best Approach for Diabetic Foot Osteomyelitis

The Spanish authors note that the treatment of osteomyelitis of the feet in diabetes patients is a controversial issue, with choice of therapy often based on the anatomic site of infection, the local vascular supply, the extent of soft-tissue and bone destruction, the presence of necrosis, systemic signs of infection, and the patients' and clinicians' preferences.

Surgery has been the mainstay of treatment, but use of antibiotics in this patient population avoids the cost and potential complications of surgery. There are, however, pros and cons to both methods of treatment, the researchers say, adding: "The optimum approach is currently being debated, and the definitive role of surgery and antibiotic treatment is not sufficiently well clarified."

In this study, they randomized 52 patients with diabetes and foot osteomyelitis to either antibiotics for 90 days (n = 25) or surgery followed by a short course of postoperative antibiotic treatment for 10 days (n = 27) between 2010 and 2012.

The actual choice and doses of antibiotic therapy depended on what patients had been taking prior to the study and included amoxicillin/clavulanic acid, trimethoprim, ciprofloxacin, trimethoprim/sulfamethoxazole, clindamycin, levofloxacin, and tetracycline.

Dr. Lázaro-Marinez explained that while the trial was open to all patients with diabetic foot osteomyelitis, in practice those with ulcers localized in sites other than the forefoot, such as the heel, tended to have complications such as ischemia, which excluded them from participating. These patients were deemed to require other treatments, such as revascularization, he explained.

No Differences in Healing or Complications

After 12 weeks, 18 patients (75%) had achieved primary healing in the antibiotic group compared with 19 in the surgery group (86.3%), a nonsignificant difference (P = .33).

The median time to healing was 6 weeks in the antibiotic group and 7 weeks in the surgery group. Four patients from the antibiotic group worsened (16.6%) and underwent surgery. Three patients from the surgery group required reoperation. No difference was found between the 2 groups regarding minor amputations (P = .336).

"The present study is the first reported attempt in the medical literature to compare the treatment of diabetic foot osteomyelitis exclusively based on antibiotic therapy with surgery followed by a short postoperative period of antibiotics," say Dr. Lázaro-Marinez and colleagues.

"No differences were found between the 2 types of treatment in healing rate and time to achieve healing in our trial. Complications were similar in both groups, and no differences in minor amputations as a result of complications were found."

Although the researchers acknowledge some limitations of the study, including the small sample size and the short follow-up of 12 weeks — meaning that mid- and long-term reoccurrences could not be analyzed — they also note some strengths. These include the fact that all surgeries were performed by the same surgeon, in an experienced center exclusively dedicated to treating diabetic foot problems.

Dr. Lázaro-Marinez said the findings yield "very useful information" for diabetic foot doctors, indicating that, at least in this type of patient, "you can start with antibiotics." If there is no improvement after 90 days, then "the second option is surgery," he concluded.

Dr. Lázaro-Marinez and coauthors have reported no relevant financial relationships. Dr. Boulton is an associate editor of Diabetes Care and is currently president of the European Association for the Study of Diabetes .

Diabetes Care. Published online October 15, 2013. Abstract


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