Chronic osteomyelitis in a new rabbit model.

Dogs, rats, and rabbits are the most suitable species to induce chronic osteomyelitis and to study different methods of treatment. In rabbits, the incidence of and mortality from Staphylococcus aureus-induced osteomyelitis of the tibia depends on the method of prelesions and the amount and virulence of species-specific bacteria used. In this study two different lesions were combined simultaneously in the medullary canal of the femurs by aspiration of bone marrow, leaving the insertion needle in situ. A sclerosing agent was then inoculated followed by 300,000 bacteria of a rabbit-derived S. aureus strain to initiate infection. With this method, the incidence of chronic progressive osteomyelitis of the femur was increased to 100%. A relatively low mortality was observed, probably due to a lower number of inoculated bacteria as compared to other rabbit models described. The incidence of acute to chronic osteomyelitis was diagnosed by local signs, x-rays, microbiological recovery, and gross pathology of the femur. Initial fever, weight loss, abscess formation in soft tissues, and pain on palpation characterize the clinical features in the course of development of this chronic disease.