Induktion und Prophylaxe Implantat assoziierter Knocheninfektionen am Modell eines antiinfektiv beschichteten Marknagels

Induction and prophylaxis of implant-related bone infections using an antibacterial-coated intramedullary nail – an experimental rabbit model Despite modern peri-operative antimicrobial prophylaxis, bone infections still represent dangerous complications in orthopedic and trauma surgery. Bacterial colonization of implanted material is the first step in pathogenesis of these infections. The objective of this study was to evaluate the effectiveness from a new biodegradable, stable, antibacterial gentamicin-loaded poly-(D,L-lactide) (PDLLA) coating of orthopedic devices. In vitro, elution kinetics of gentamicin and furthermore, biocompatibility and effectiveness in preventing implant-related osteomyelitis should be studied in vivo. Coating of commercial steel implants was performed by a so-called cold coating technique under aseptic conditions. The carrier was the polymer poly-(D,L-lactide) Resomer® R 203 and gentamicin was incorporated in a 10 % (w/w) concentration. Release kinetics of gentamicin were tested in vitro for 96 hours. To study the biocompatibility, in a group of eleven rabbits nails uncoated (n=5) or nails coated with PDLLA and gentamicin (n=6) were implanted into the femur. Serum gentamicin was determined after 12, 24, 48 hours and then weekly. Follow-up was six weeks. After sacrifice the femora were examined by histologic and radiologic means. In a second group of 20 rabbits, the medullary cavities of femora were contaminated with 105 CFU Staphylococcus aureus after implantation of uncoated (n=10) or coated (n=10) nails. Serum gentamicin, blood samples and clinical presentation were examined. Follow-up was eight weeks. After sacrifice the femora were evaluated by microbiological, histological and radiological analysis. The incorporated gentamicin was released continuously over a period of at least 96 hours with an initial peak of release in the first 24 hours. In the biocompatibility group, radiological and histological studies revealed no adverse effects on bone contributed to the PDLLA coating. In the osteomyelitis group, all controls developed abscesses and histological signs of osteomyelitis. In nine of ten rabbits which had an implant coated with gentamicin abscesses were not detected. Histological signs of infection were reduced. No significant differences in clinical and radiological presentation were observed between the groups. In our animal model with an infective dosis of 105 CFU Staphylococcus aureus, local application of nails coated with PDLLA and gentamicin significantly reduced implant-related bone infections. The use of the gentamicin-PDLLA-coating could be an effective supplement for prophylaxis of implant-related infections in orthopedic and trauma surgery.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Ludwig-Maximilians-Universität

Year

2004

Author dc:creator

• Rößner, Michaela

Repository record source_url

https://edoc.ub.uni-muenchen.de/2470/

OAI identifier oai:identifier

oai:edoc.ub.uni-muenchen.de:2470