A histological study of acute hematogenous osteomyelitis following physeal injuries in rabbits.

In young rabbits, the effects of an intravenous injection of Staphylococcus aureus alone, and in combination with a traumatic injury of the proximal tibial physis, were studied by light and electron microscopy. Metaphyseal osteomyelitis and radiographic changes were seen within forty-eight hours after the injury in all rabbits that had a growth-plate disruption and bacteremia. An intravenous injection of bacteria alone produced no morphological or microbiological evidence of infection. In the absence of trauma, normal tibiae were sterile after forty-eight hours. Foreign-body particles have been shown to accumulate in the fine vessels that are adjacent to the growth plate, but we found no similar deposition of bacteria or evidence of phagocytic removal in this area. Phagocytosis of bacteria by neutrophils did not appear to be impaired in the distal third of the metaphysis, but a delayed inflammatory response that allowed proliferation of bacteria and destruction of tissue was observed in the proximal two-thirds of the metaphysis after trauma.