Current Concepts In Treating Diabetic Foot Osteomyelitis
Diabetic foot osteomyelitis continues to be one of the more challenging entities to diagnose and treat accurately. Although there are established clinical practice guidelines set forth by the Infectious Diseases Society of America (IDSA), deviations from these guidelines often exist from one treatment facility to the next.1
Many physicians continue to dogmatically use the so-called “standard” regimen of six weeks of parenteral antibiotics for every patient with bone infection regardless of the clinical situation. Several recent studies have cast doubt on the superiority of parenteral agents versus oral agents, and have re-examined the need for surgical debridement.2-5
Accordingly, let us take a closer look at these issues and others in the diagnosis and management of diabetic foot osteomyelitis.
Can We Treat Diabetic Foot Osteomyelitis Without Surgical Intervention?
The question of whether osteomyelitis of the diabetic foot can be treated without surgical intervention is often debated. Many clinicians feel that osteomyelitis cannot be treated effectively if one does not excise infected bone early on in the infectious process. Other physicians have argued that one can address osteomyelitis with minimal debridement and appropriate antibiotic treatment, and that physicians should reserve surgical debridement for those patients who are unresponsive to treatment or those with limb-threatening infections.2
In their retrospective study of 147 patients with osteomyelitis, Game and Jeffcoate treated 113 patients with antibiotics alone. Of those 113 patients, 93 (82.3 percent) achieved remission without surgery. The remaining 34 either underwent minor amputation (28 patients) or major amputation (six patients). Of the 28 undergoing minor amputations, 22 achieved remission (78.6 percent).2
In both groups, the two most common oral antibiotic regimens were either amoxicillin/clavulanic acid (Augmentin, GlaxoSmithKline) or clindamycin in combination with ofloxacin or ciprofloxacin (Cipro, Bayer). If the researchers identified methicillin-resistant Staphylococcus aureus, they either added the following drugs to the regimen or substituted them for other antibiotics: trimethoprim (Bactrim, Roche), doxycycline (Vibramycin, Pfizer), fusidic acid (not available in the U.S.) or rifampicin (Rifadin, Sanofi Aventis).2
These findings form a strong argument against the 2004 study of 224 patients by Henke and colleagues, who maintained that “conservative management worsens lower extremity salvage.”6
What One Study Reveals About Using Oral Antibiotics Alone
A 2006 retrospective study by Embil and colleagues looked at the efficiency of oral antibiotics alone in the treatment of osteomyelitis of the diabetic foot.3 Operative facilities and home intravenous antibiotic therapy programs are not always available in more remote or rural settings. In these settings, oral antibiotics are often the only treatment options.
Typically, the treatment of osteomyelitis consists of debridement of infected tissue and bone along with a four- to six-week regimen of parenteral antibiotics. Some recent studies have described the use of a shorter course of parenteral antibiotics followed by a longer course of oral antibiotics.7-10 Embil and co-authors proposed that oral antibiotics with or without limited debridement is an effective way to treat osteomyelitis of the foot.3
The study authors diagnosed osteomyelitis if there was a grade 3 Wagner ulcer with drainage plus at least one of the following criteria: evidence of bone destruction on plain radiographs; localized increased uptake on technetium bone scan with or without gallium; bone at the base of the ulcer that one could see, probe or palpate; or a positive bone culture showing microbial pathogens.3