Pathologic effects of vaccinia virus on rabbit bone and marrow. An experimental study

Although viruses have recently been implicated in the pathogenesis of Paget's disease and Perthes' disease, little information is available regarding bone and marrow response to the presence of a noncarcinogenic virus. Vaccinia virus was introduced into the medullary cavity of the femoral shaft of 30 New Zealand White rabbits, and an appropriate control inoculation was performed. Virus was recovered from the inoculation site in 50% of the animals at intervals to one month after inoculation. Histologic abnormalities were observed in 69% of the test femora; similar abnormalities were not observed in the control femora. These abnormalities consisted of bone and marrow necrosis, lymphocyte and plasma cell infiltration, and new bone formation. Some of the newly formed bone was also necrotic. The latter observation suggests an alternative mechanism for the death of new bone, which, in Perthes' disease, has customarily been attributed to repeated ischemic insults.