Osteomyelitis is an acute or chronic bone infection, usually
caused by bacteria.
Information about Osteomyelitis
The infection that causes osteomyelitis often is in another part
of the body and spreads to the bone via the blood. Affected bone may have been predisposed
to infection because of recent trauma.
In children, the long bones are usually affected. In adults, the vertebrae and the
pelvis are most commonly affected. Bone infection can be caused by bacteria or by fungus.
When the bone is infected, pus is produced within the bone, which may result in an
abscess. The abscess then deprives the bone of its blood supply.
Chronic osteomyelitis results when bone tissue dies as a result of the lost blood supply.
Chronic infection can persist intermittently for years.
Risk factors are recent trauma, diabetes, hemodialysis, and intravenous drug abuse.
People who have had their spleen removed are also at higher risk for osteomyelitis.
The incidence of osteomyelitis is 2 in 10,000 people.
Symptoms of Osteomyelitis
- Pain in the bone
- Local swelling, redness, and warmth
- General discomfort, uneasiness, or ill feeling (malaise)
- Drainage of pus through the skin (in chronic osteomyelitis)
- Low back pain
- Swelling of the ankles, feet, and legs
Causes of Osteomyelitis
Staphylococcus aureus, a bacterium, is the most common organism involved in
osteomyelitis. Other types of organisms include the mycobacterium which causes
tuberculosis, a type of Salmonella bacteria in patients with sickle cell anemia, Pseudomonas
aeurginosa in drug addicts, and organisms which usually reside in the gastrointestinal
tract in the elderly. Extremely rarely, the viruses which cause chickenpox and smallpox
have been found to cause a viral osteomyelitis.
There are two main ways that infecting bacteria find their way to bone, resulting in
the development of osteomyelitis. These include:
- Spread via the bloodstream; 95% of these types of infections are due to Staphylococcus
aureus. In this situation, the bacteria travels through the bloodstream to reach the
bone. In children, the most likely site of infection is within one of the long bones,
particularly the thigh bone (femur), one of the bones of the lower leg (tibia), or the
bone of the upper arm (humerus). This is because in children these bones have particularly
extensive blood circulation, making them more susceptible to invasion by bacteria.
Different patterns of blood circulation in adults make the long bones less well-served by
the circulatory system. These bones are therefore unlikely to develop osteomyelitis in
adult patients. Instead, the bones of the spine (vertebrae) receive a lot of blood flow.
Therefore, osteomyelitis in adults is most likely to affect a vertebra. Drug addicts may
have osteomyelitis in the pubic bone or clavicle.
- Spread from adjacent infected soft tissue; about 50% of all such cases are infected by Staphylococcus
aureus. This often occurs in cases where recent surgery or injury has result in a soft
tissue infection. The bacteria can then spread to nearby bone, resulting in osteomyelitis.
Patients with diabetes are particularly susceptible to this source of osteomyelitis. The
diabetes interferes with both nerve sensation and good blood flow to the feet. Diabetic
patients are therefore prone to developing poorly healing wounds to their feet, which can
then spread to bone, causing osteomyelitis.
Acute osteomyelitis refers to an infection which develops and peaks over a relatively
short period of time. In children, acute osteomyelitis usually presents itself as pain in
the affected bone, tenderness to pressure over the infected area, fever and chills.
Patients who develop osteomyelitis, due to spread from a nearby area of soft tissue
infection, may only note poor healing of the original wound or 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 note 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. The lower back is the most common location for
osteomyelitis. When caused by tuberculosis, osteomyelitis usually affects the thoracic
spine (that section of the spine running approximately from the base of the neck down to
where the ribs stop).
When osteomyelitis is not properly treated, a chronic (long-term) type of infection may
occur. In this case, the infection may wax and wane indefinitely, despite treatment during
its active phases. An abnormal opening in the skin overlaying the area of bone infection
(called a sinus tract) may occasionally drain pus. This type of smoldering infection may
also result in areas of dead bone, called sequestra. These areas occur when the infection
interferes with blood flow to a particular part of the bone. Such sequestra lack cells
called osteocytes, which in normal bone are continuously involved in the process of
producing bony material.
Diagnosis of Osteomyelitis
Diagnosis of osteomyelitis involves several procedures. Blood is usually drawn and
tested to demonstrate an increased number of the infection-fighting white blood cells
(particularly elevated in children with acute osteomyelitis). Blood is also cultured in a
laboratory, a process which allows any bacteria present to multiply. A specimen from the
culture is then specially treated, and examined under a microscope to try to identify the
Injection of certain radioactive elements into the bloodstream, followed by a series of
x-ray pictures, called a scan (radionuclide scanning), will reveal areas of bone
inflammation. Another type of scan used to diagnose osteomyelitis is called magnetic
resonance imaging, or MRI
When pockets of pus are available, or overlaying soft tissue infection exists, these
can serve as sources for samples which can be cultured to allow identification of bacteria
present. A long, sharp needle can be used to obtain a specimen of bone (biopsy), which can
then be tested to attempt to identify any bacteria present.
Treatment of Osteomyelitis
Antibiotics are medications used to kill bacteria. 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 of intravenous antibiotic treatment is usually recommended, along with
bed-rest for part or all of that time. Occasionally, a patient will have such extensive
ostemyelitis that surgery will be required to drain any pockets of pus, and to clean the
Alternative treatment of Osteomyelitis
General recommendations for the treatment of infections include increasing vitamin
supplements, such as vitamins A and C. Liquid garlic extract is sometimes suggested.
Guided imagery can help induce relaxation and improve pain, both of which are considered
to improve healing. Herbs such as echinacea (Echinacea spp.), goldenseal (Hydrastis
canadensis), Siberian ginseng (Eleutherococcus senticosus), and myrrh (Commiphora
molmol) are all suggested for infections. Juice therapists recommend drinking
combinations of carrot, celery, beet, and cantaloupe juices. A variety of homeopathic
remedies may be helpful, especially those used to counter inflammation.