Osteomyelitis: Inflammation of the bone due to infection, for example, by the bacteria salmonella or staphylococcus. Osteomyelitis is sometimes a complication of surgery or injury, although infection can also reach bone tissue through the bloodstream. Both the bone and the bone marrow may be infected. Symptoms include deep pain and muscle spasms in the area of inflammation, as well as fever. Treatment includes bed rest, use of antibiotics, and sometimes surgery to remove dead bone tissue.