Osteomyelitis is an acute or chronic bone infection, usually caused by bacteria.

Bone infection can be caused by bacteria or by fungus. The infection that causes osteomyelitis often starts in another part of the body and spreads to the bone through the blood. An injury may have made the affected bone more likely to develop the infection.

In children, the long bones are usually affected. In adults, the feet, vertebrae, and the pelvis are most commonly affected.

Risk factors are recent trauma, diabetes, hemodialysis, and IV drug abuse. People who have had their spleen removed are also at higher risk for osteomyelitis.

Osteomyelitis affects about 2 in 10,000 people.

• Bone pain
• Fever
• General discomfort, uneasiness, or ill-feeling (malaise)
• Local swelling, redness, and warmth
• Nausea

Additional symptoms that may be associated with this disease:

• Chills
• Excessive sweating
• Low back pain
• Swelling of the ankles, feet, and legs

A physical examination shows bone tenderness and possibly swelling and redness.

Tests may include:

• Blood cultures
• Bone lesion biopsy
• Bone scan
• MRI
• Needle aspiration of the area around affected bones

This disease may alter the results of the following tests:

• Bone x-ray
• C-reactive protein (CRP)

The objective of treatment is to eliminate the infection and prevent it from getting worse.

Antibiotics will be given to destroy the bacteria that are causing the infection.

Surgery may be needed to remove dead bone tissue if you have an infection that does not go away. The open space left by the removed bone tissue may be filled with bone graft or packing material that promotes the growth of new bone tissue. Antibiotics are continued for at least 6 weeks after surgery.

Infection of an orthopedic prosthesis may require surgical removal of the prosthesis and infected tissue surrounding the area. A new prosthesis may be implanted in the same operation or delayed until the infection has gone away.

When treatment is received, the outcome for acute osteomyelitis is usually good.

The outlook is worse for those with long-term (chronic) osteomyelitis, even with surgery. Amputation may be needed, especially in those with diabetes or poor blood circulation.

The outlook is guarded in those who have an infection of a prosthesis.

When the bone is infected, pus is produced within the bone, which may result in an abscess. The abscess steals the bone's blood supply. The lost blood supply can result in a complication called chronic osteomyelitis. This chronic infection can persist on and off for years.

Other complications include:

• Need for amputation
• Reduced limb or joint function
• Spread of infection

Call your health care provider if you have symptoms of osteomyelitis, or if you have osteomyelitis and the symptoms persist despite treatment.

Prompt and complete treatment of infections is helpful. High-risk people should see a health care provider promptly if they have signs of an infection anywhere in the body.

Berbari EF, Steckelberg JM. Osmon DR. Osteomyelitis. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 6th ed. London: Churchill Livingstone; 2005:chap 99.

Espinoza LR. Infections of Bursae, Joints, and Bones. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 293.