Osteomyelitis, defined as an inflammation of bone generally caused by a pyogenic organism, is a common disorder of childhood. Infection most commonly is caused by blood-borne bacteria that localize in the metaphysis. Trauma or surgery also may result in direct inoculation or implantation of bacteria into the bone, or an adjacent focus of infection might extend directly to the bone, resulting in osteomyelitis.
The etiology of acute hematogenous osteomyelitis is not understood completely. Bacteremia in childhood occurs frequently, if not daily; thus, the presence of bacteria alone may not explain why infection begins. Recent trauma coincidental with a bacteremia has been postulated. The presence of an intercurrent illness (ie, chicken pox) or infection may introduce a larger number of organisms or different pathogenic bacteria into the system or alter the immune system, making the host more susceptible.
An understanding of the anatomy of bone and the pathogenesis of osteomyelitis is essential to appreciate the protean manifestations of the disorder.
Pathogenesis
In acute hematogenous osteomyelitis, infection is localized in the metapahysis. The circulation of the bone predisposes this region to the infection. Epiphyseal and metaphyseaal blood supplies generally are separate. The blood supply to the metaaphysis originagtes when the nutrient arteries send small terminala branches that end at the growth plate.
Delayed Diagnosis and Treatment of Pediatric Calcaneal Acute Hematogenous Osteomyelitis: A Case Report
