Efficacy of a norvancomycin-loaded, PDLLA-coated plate in preventing early infection of rabbit tibia fracture.

Abstract

Despite improvements in surgical techniques and implant designs in orthopedic surgery, implantation-associated infections are still a challenging problem for surgeons. The goal of this study was to evaluate the efficacy of a norvancomycin-loaded, PDLLA-coated stainless steel plate vs an uncoated stainless steel plate in a rabbit model (n=50). The norvancomycin was delivered from a biodegradable poly(D,L-lactide) (PDLLA) coating of a stainless steel plate. Intraoperatively, rabbit tibia fractures were contaminated with Staphylococcus aureus (10(5) colony forming units) after plate implantation. The implants were either uncoated or coated with PDLLA and norvancomycin. In vivo drug release profiles showed that the norvancomycin release rate was decreased by increasing the time. The norvancomycin concentration in the tissue around the plate was higher than the minimum inhibitory concentration on the 14th day after implantation surgery. The animals were followed up for 28 days. Radiographic examinations were performed, and C-reactive protein and erythrocyte sedimentation rate were determined. Infection was evaluated by histological, microbiological, and radiological analysis. Eight of 25 rabbits (32%) implanted with the norvancomycin-loaded, PDLLA-coated plates were infected. Twenty-three of 25 rabbits (92%) implanted with the uncoated plates were infected (P<.05). The norvancomycin-loaded, PDLLA-coated plate may be used to treat open fractures to reduce the incidence of early infection.