1. Hematogenous osteomyelitis is due to the growth of bacteria which have reached the interior of bone by transport through the blood stream. Bacteria of various kinds may be concerned, but the staphylococcus aureus is responsible in most instances.
2. Localization of the disease process depends upon diminished resistance at particular sites, associated with growth activity at the metaphysis or with trauma at any place. In the absence of trauma, the marrow of the shaft is relatively resistant to infection because of the efficiency of its endothelial cells in the phagocytosis and destruction of bacteria.
3. A consideration of the bacteriological relationships indicates the wisdom of a conservative attitude in dealing with acute hematogenous osteomyelitis.