New Study Suggests Shorter Duration Of Antibiotics For Diabetic Foot Osteomyelitis

Diabetic foot osteomyelitis remains one of the most challenging conditions to manage and treat in the foot and ankle. It is associated with high rates of recurrence, significant morbidity and mortality and costs.¹ Diagnosis can be particularly challenging in the presence of diabetes due to an often blunted neuroinflammatory response, in which the usual manifestations of infection (e.g., fever, tachycardia, elevated white blood cell count) are frequently absent. When necessary, definitive diagnosis should be based on the collection of suspected bone for culture and pathology.¹ Appropriate use of imaging and biomarkers for the diagnosis of diabetic foot osteomyelitis is certainly important, but beyond the scope of this blog.

As far as treatment goes, antibiotics alone may suffice in some cases. However, diabetic foot osteomyelitis cases often require surgical resection of the infected bone in addition to antibiotics. Yet little evidence exists regarding the optimum duration of antibiotic treatment for diabetic foot osteomyelitis and overuse of antibiotics may lead to increased side effects, the development of antibiotic resistance, and increased costs.² According to the most recent guidelines from the International Working Group on the Diabetic Foot (IWGDF), the treatment of diabetic foot osteomyelitis with antibiotics should last no longer than six weeks.²  

However, new research published in Clinical Infectious Diseases suggests that even less treatment time with antibiotics may be adequate for treating diabetic foot osteomyelitis.³ In a prospective, randomized pilot trial, Gariani and colleagues noted that a post-debridement systemic antibiotic therapy course of three weeks resulted in similar rates of remission and adverse events in comparison to a six-week course. In fact, the authors found that 78 percent of patients in the study with diabetic foot osteomyelitis remained in clinical remission after a median follow-up of 11 months.

While the results are promising, Gariani and coworkers do acknowledge certain limitations based on the very nature of the pilot design including but not limited to: a small sample size and a lack of subgroup/population analysis (i.e. patients with limb ischemia); relatively short follow-up; and inability to specify the role of each individual pathogen on the likelihood of remission from DFO.³ 

However, further studies are underway. If the results of those studies confirm the findings of the aforementioned pilot study, the clinical implications for treating diabetic foot osteomyelitis with antibiotics could be profound. Indeed, these preliminary findings may offer a glimmer of hope in the face of a very daunting problem. 

Dr. Isaac is the Director of Research with Foot & Ankle Specialists of the Mid-Atlantic (FASMA). He is a Diplomate of the American Board of Foot and Ankle Surgery.

References

1. Lipsky BA, Berendt AR, Cornia PB, et al. 2012 Infectious Diseases Society of America clinical practice guideline for the diagnosis and treatment of diabetic foot infections. Clin Infect Dis. 2012;54(12):e132-73.

2. Lipsky BA, Senneville É, Abbas ZG, et al. Guidelines on the diagnosis and treatment of foot infection in persons with diabetes (IWGDF 2019 update). Diabetes Metab Res Rev. 2020;36 (Suppl 1):e3280.

3. Gariani K, Pham TT, Kressmann B, et al. Three versus six weeks of antibiotic therapy for diabetic foot osteomyelitis: A prospective, randomized, non-inferiority pilot trial. Clin Infect Dis. 2020. Available at: https://doi.org/10.1093/cid/ciaa1758 . Accessed January 4, 2021.