It may just be “the way it is done” when surgeons sprinkle vancomycin powder topically throughout the surgical site after spine surgery or joint reconstruction and before wound closure. Surely, this antibiotic on the World Health Organization’s List of Essential Medicines will help to combat infection.
However, where is the evidence-based data to support the use of the powder?
Some question whether the drug is efficacious, cost-effective, or possibly even counterproductive. Many publications and presentations at orthopedic congresses attempt to address these questions, though few investigate the basic science, dose response, or include randomization.
A new study from the University of California Los Angeles (UCLA) took a look at vancomycin in an in vivo mouse model. The publication, “Progress not panacea: vancomycin powder efficacy and dose evaluated in an in vivo mouse model of spine implant infection,” appears in the June 2020 issue of The Spine Journal.
The study authors implanted spine implants infected with bioluminescent Staphlococcus aureus. They found that mice treated with vancomycin powder prior to wound closure had significantly fewer persistent infections. Further, there was a dose response showing greater infection rates with smaller doses of vancomycin.
The authors pointed out that vancomycin was ineffective at completely eliminating infection in all mice that received treatment. The work suggests that vancomycin powder can be effective, even in lower doses for patients that may have contraindications for high concentrations of vancomycin.
Is Vancomycin Powder Cost Effective?
Another consideration on the minds of surgeons and, especially hospital administrators, is the cost effectiveness of vancomycin. A pair of studies published in 2019 calculated the cost effectiveness of using vancomycin powder for hip arthroplasty, and lumbar laminectomy. Both studies calculated the absolute risk reduction, or the number of infections that must be prevented based on the costs associated with the infection to justify the cost of using the drug.
The study published in the journal Orthopedics, “Efficacy and Cost-effectiveness of Topical Vancomycin Powder in Primary Cementless Total Hip Arthroplasty,” found that, though there was no statistically significant difference in the study cohorts given vancomycin or not, there was an absolute risk reduction of 0.98%, suggesting that a $12 dose of vancomycin powder results in a savings of $904 per patient. A larger trial may provide the statistical significance lacking in this 309-patient study.
The second study, published in the Global Spine Journal, “The Cost-Effectiveness of Vancomycin Powder in Lumbar Laminectomy,” Kerbel, M.D., et al. found that an absolute risk reduction of at least 0.015% for lumbar laminectomy, or 0.0034% for lumbar laminectomy with fusion would suggest cost-effectiveness. The group concluded that the reductions required in infection rate were so miniscule that treatment is highly cost effective.
An important consideration, one that even patients may have developed while watching or reading the news, is whether application of vancomycin powder contributes to antibacterial resistance. A 2019 study published in Spine Deformity, “Local Application of Vancomycin in Spine Surgery Does Not Result in Increased Vancomycin-Resistant Bacteria—10-Year Data,” determined that over a 10-year period from 2007 to 2017, there was no association between vancomycin-resistant bacteria found in surgical site infections and vancomycin application. The study did, however, find an increase in gram-negative infections in patients that received topical vancomycin.
