Vancomycin Bound to Ti Rods Reduces Periprosthetic Infection Preliminary Study

A major challenge in treating periprosthetic infection is the predilection of certain bacteria to colonize implants, form biofilms, and resist treatment. We engineered an innovative self-protective implant with covalently bound antibiotics that prevents bacterial colonization and remains stable for extended periods of time. To test this surface in vivo, we developed a rat periprosthetic infection model with an intramedullary implant in S. aureus-infected femora. Using the model, we then evaluated the effect of vancomycin-modified titanium rods on the clinical presentation of bone infection. Finally, assuming delayed and chronic periprosthetic infections originate from biofilms atop contaminated implants, the numbers of surface adherent bacteria were measured to assess the capability of the implant to prevent biofilms. S. aureus (1.5 × 10³ colony forming units) with no known resistance were injected into the femoral canal of Wistar rats, followed by the implant. Signs of infection were assessed weekly by direct clinical observation of the animals, radiograph, and microCT, and counts of bacteria adherent to the implant. Vancomycin-modified implants showed superior inhibition of bacterial attachment and proliferation compared to control titanium surfaces.