Osteomyelitis is a bone infection, almost always caused by bacteria. Over time, the infection can destroy the bone.
Bone infections may occur at any age. Certain conditions increase the risk ofdeveloping such an infection, including sickle-cell anemia, injury, the presence of a foreign object (such as a bullet or a screw placed to hold togethera broken bone), intravenous drug use (such as heroin), diabetes, kidney dialysis, surgical procedures to bony areas, and untreated infections of tissue near a bone (for example, extreme cases of untreated sinus infections have ledto osteomyelitis of the bones of the skull).
Staphylococcus aureus is the type of bacterium usually involved in osteomyelitis. Others include the mycobacterium which causes tuberculosis, a type of Salmonella bacterium in patients with sickle cell anemia, and Pseudomonas aeurginosa in drug addicts. The viruses that cause chickenpox and smallpox can cause viral osteomyelitis, but this is very rare.
Infecting bacteria can find their way to the bone by traveling through the bloodstream or by spreading from nearby infected soft tissue. Children are mostlikely to be infected in the long bones of the arms and legs, because theirgrowing bones are richly supplied with blood. Adults have different blood circulation patterns, so they are less likely to get osteomyelitis in the arms and legs, but more likely to develop the condition in the spine. People with diabetes are especially likely to develop osteomyelitis by the spread of infection from nearby soft tissue. This is because diabetes interferes with nervesensation and good blood flow to the feet, making patients prone to developing poorly healing wounds to their feet. These wounds can become infected, andthe infection can spread to bone.
Acute osteomyelitis refers to a bone infection that develops and peaks over arelatively short time. In children, symptoms of acute osteomyelitis usuallyinclude pain in the affected bone, tenderness to over the infected area, fever and chills. Patients who develop osteomyelitis due to the spread of infection from nearby soft tissue may only notice poor healing of the original woundor infection.
Adult patients with osteomyelitis of the spine usually have a longer period of dull, aching pain in the back, and no fever. Some patients notice pain in the chest, abdomen, arm, or leg. This occurs when the inflammation in the spine causes pressure on a nerve root serving one of these other areas.
Doctors use several tests to diagnose osteomyelitis. Blood tests or cultures,x rays and magnetic resonance imaging (MRI) all may be used.
Antibiotics (medications used to kill bacteria) are used to treat osteomyelitis. These medications are usually given through a needle in a vein (intravenously) for at least part of the time. In children, these antibiotics can be given by mouth after initial treatment by vein. In adults, four to six weeks ofintravenous antibiotic treatment is usually recommended, along with bed restfor part or all of that time. Occasionally, a patient will have such extensive osteomyelitis that surgery will be required to clean the infected area.
When osteomyelitis is not properly treated, a chronic (long-term) type of infection may occur. However, with quick, appropriate treatment, only about 5% of all cases of acute osteomyelitis will eventually become chronic osteomyelitis. Patients with chronic osteomyelitis may require antibiotics periodicallyfor the rest of their lives.
Carefully caring for any wounds or injuries will lessen the risk of developing osteomyelitis.