It is caused by blood-borne microorganisms (hematogenous osteomyelitis); it spreads from infected tissues, including joint replacement infections, contaminated fractures and bone surgery. The most common pathogen is Gram-positive bacteria. Osteomyelitis caused by Gram-negative bacteria can be seen in drug users, patients with sickle cell hemorrhage and patients with severe diabetes or trauma. Pathological changes in fungal and Mycobacterium infections are often confined to bone and cause painless chronic infections. Risk factors include consumptive diseases, radiotherapy, malignant tumors, diabetes, hemodialysis and intravenous medication. For children, any process that causes bacteremia can cause osteomyelitis.
