Evaluation of Biodegradable Adjunctive Therapy for Extremity Wound Infection Reduction

Infection remains a serious potential complication despite continuing advances in the treatment of open fractures and musculoskeletal wounds from high-energy trauma such as motor vehicle accidents, falls, gunshots, or explosives. These evaluations examined an adjunctive therapy approach to the initial surgical debridement, irrigation, and lavage for bacterial contamination reduction in these traumatic extremity injuries. Two known biodegradable biomaterials, calcium sulfate and chitosan, were evaluated in two different delivery formats to provide local antibiotic delivery for these complex wounds.

The preclinical evaluations of these two known biomaterials involved formulation, degradation, elution, bioactivity, and functional testing. The calcium sulfate construct provided antibiotic elution for 12-16 hours and construct degradation in 24 hours. The chitosan construct provided antibiotic elution for 48-72 hours and partial to complete construct degradation in 72 hours. The in-vivo assessments of these constructs in a contaminated complex extremity trauma animal model with Pseudomonas aeruginosa and Staphylococcus aureus demonstrated greater than 2x-3x reduction in bacterial contamination after 42 hours with little or no bacterial rebound effect that typically occurs after the initial debridement, irrigation, and lavage. Additional investigations are planned with these biomaterials for this adjunctive therapy on complex extremity injuries.