Treatment of osteomyelitis with local antibiotics delivered via bioabsorbable polymer

The purpose of the current study was to show the efficacy and safety of an absorbable polymer (polycaprolactone) as an antibiotic delivery vehicle for treatment of osteomyelitis. An intramedullary osteomyelitis was induced in the femur of adult rabbits by Staphylococcus aureus inoculation after use of a sclerosing agent, and then treatment was done with intramedullary irrigation and implantation of a rod made of polycaprolactone, polycaprolactone plus 6% tobramycin, or polymethylmethacrylate plus 6% tobramycin. A control group received irrigation only. At defined intervals, the animals were euthanized and culture of the inoculated site was done. In addition, histologic sections of body tissues were made to look for signs of systemic toxicity of the implant. After 4 weeks of treatment, a statistically significant difference was found between the animals that were treated with irrigation alone and the animals that were treated with antibiotic-laden rods of polycaprolactone or polymethylmethacrylate. There was no difference between the antibiotic rod types. No histologic evidence of toxicity was found. Bioabsorbable rods of polycaprolactone are a safe and effective means of antibiotic delivery for treatment of osteomyelitis.