The Potential of Topical Antibiotic Powder to Decrease Infection Rates in Total Ankle Arthroplasty

Abstract

Category: Ankle; Ankle Arthritis; Other Introduction/Purpose: Periprosthetic infection is a devastating complication in total ankle arthroplasty (TAA). Measures that can reduce or eliminate infection occurrence are warranted for further investigation, particularly if they also minimize added costs, operative time or potential adverse effects. There remains insufficient evidence to show definitive benefits or risks associated with use of local antibiotics such as vancomycin for infection prevention. The purpose of this study was to determine the effects of topical vancomycin powder application in TAA and whether it may decrease infection rate in the subacute postoperative period. To our knowledge, this is the first comparative study in a general population undergoing TAA. Methods: A retrospective study was conducted based on a consecutive series of patients who underwent TAA performed by a single senior surgeon. The control group without vancomycin powder was matched to the study group that received application over the implants prior to closure, which was based on when the surgeon transitioned to usage in all patients. Various demographic data for the patients was collected. Only patients with a minimal follow up of 80 days were included in order to capture the perioperative period of infection. Infection rate was based on a definition of deep infection necessitating inpatient hospitalization for IV antibiotics and/or surgical intervention. The associations of various demographic factors and vancomycin application with infection rate were calculated with chi square and odds ratio. Significance level was set to 0.05. Results: A total of 252 patients (n=103 without, and 149 with vancomycin powder) were included in the study. The overall infection rate was 3.2%, which was not correlated with a history of diabetes, BMI, additional concurrent surgery, or age, but was associated with current positive smoking status (p=0.03). The infection rates between the groups that received or did not receive vancomycin powder were not statistically significantly different (2.7% vs 3.9%, respectively, p=0.59). The odds ratio (OR) of infection with vancomycin powder was not statistically significant either, at OR=0.68 (95% CI 0.17-2.81). However, the vancomycin group did have a significantly higher number of patients with previous wound issues (12 vs. 2; p=0.04) and infection (7 vs. 0; p=0.04) as well as concomitant surgeries (81 vs. 41; p=.02). Conclusion: The consequences of periprosthetic TAA infection are substantial, and the risks should be mitigated. Although this study did not detect a statistically significant difference in infection rates between patients who received or did not receive vancomycin powder, there was a trend towards risk reduction by about 30%. In addition, current smoking was found to be significantly associated with higher rates of infection and smoking cessation can serve as another point of intervention. As the complexity of patient factors and indications for performing total ankle arthroplasty expand, vancomycin powder offers a relatively cost-effective, safe, and convenient option to potentially reduce infection.