Experimental osteomyelitis due to Staphylococcus aureus or Pseudomonas aeruginosa: a radiographic-pathological correlative analysis.

A previously-described experimental model of bacterial osteomyelitis was used to investigate systematically the sequential radiographic and histopathological changes in the tibias of rabbits infected with either Staphylococcus aureus or Pseudomonas aeruginosa. The radiographic changes induced by both organisms were progressive, increasing in severity from the first to the fourth week after infection. The severity and extent of radiographic changes, especially that of bond destruction, were significantly greater for tibias infected with S. aureus. Histopathologically, staphylococcal disease was a severe, rapidly progressive purulent infection which led to extensive destruction of marrow and cortical bone, formation of sequestra, and frequent extraosseous extension. Disease due to P. aeruginosa was more indolent and less destructive, leading to earlier healing and no extraosseous extension. The sequential radiographic and pathological changes observed with this experimental model closely resemble those described in man and suggest that this model may be useful for future investigations of pathogenesis and therapy.