Three Weeks Versus Six Weeks of Antibiotic Therapy for Diabetic Foot Osteomyelitis: A Prospective, Randomized, Non-Inferiority Pilot Trial

SLR - October 2021 - Samuel Mason

Level of Evidence: III

Scientific Literature Review

Reviewed By: Samuel Mason, DPM
Residency Program: Northwest Medical Center – Margate, FL

Podiatric Relevance: Infection is an unavoidable part of foot and ankle surgery. Whether the goal of surgery is to remove infection, or infection becomes an inadvertent sequela of a clean procedure, infection is one of the most common surgical complications in lower extremity surgery. Many patients are also complicated by comorbid conditions, namely, diabetes mellitus. Historically, in the presence of osteomyelitis the patient has limited treatment options: six to eight weeks of intravenous antibiotics, excision of the infected bone, or in many cases, both. Prolonged antibiotic therapy results in increased risk of side effects, increased antibiotic resistance, and increased costs. This study of 93 patients aims to determine if a patient may require a shorter than conventional course of antibiotic intervention following surgical debridement, which in turn can decrease side effects and costs for the patient.

Methods: This study was a level III prospective, randomized, non-inferiority pilot trial. A total of 93 patients were placed in a 1:1 ratio into two groups by unblinded randomization, after surgical debridement of their diabetic foot osteomyelitis (DFO). One group of 44 patients received a three-week course (short arm) of antibiotics while the other of 49 patients received a six-week (long arm) course. The DFO following debridement was confirmed using tissue and bone cultures according to Infectious Disease Society of America Diabetic Foot Infection guidelines. Clinical remission of the DFO was then assessed for both treatment groups two months after the end of the antibiotic treatment. Remission was classified as a complete absence of radiographic and clinical findings of infection. Failure was classified as recurrent, persistent, new infection at original site, or secondary infection, which was confirmed either clinically or with positive bone cultures. 

Results: At the end of the active median follow up period of 11 months, 73 of the 93 (78 percent) DFO patients, achieved complete remission. The short arm group had a failure rate of 16 percent (7/44) while the long arm group had a failure rate of 27 percent (13/49). There was no statistical difference in the incidence of clinical remission or the number and severity of adverse events, which were similar between the two groups. No serious adverse events were attributed to antibiotic therapy. No inferiority was found between the two treatment regimens.

Conclusions: A shorter duration of antibiotic therapy than commonly utilized could be sufficient for treating DFO following surgical debridement. This new information can be useful as a guide to decrease costs and complications for the patient, while obtaining similar outcomes when compared to a traditionally longer duration of antibiotic therapy. Due to distinct populations, larger sample sizes are needed as well as a longer follow up period for the subjects to draw more meaningful conclusions.