ADAM Health Encyclopedia

Osteomyelitis

Definition

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

Causes

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

• Pain in the bone
• Local swelling, redness, and warmth
• Fever
• Nausea
• General discomfort, uneasiness, or ill feeling (malaise)
• Drainage of pus through the skin (in chronic osteomyelitis)

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

Exams and Tests

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

Tests may include:

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

• Joint x-ray
• Hand x-ray
• Extremity x-ray
• Bone x-ray
• ALP (alkaline phosphatase) isoenzyme
• ALP

Treatment

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.

For infections that do not go away, surgery may be needed to remove dead bone tissue. The open space left by the removed bone tissue may be filled with bone graft or by packing material to promote 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.

Outlook (Prognosis)

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

The outlook is worse for chronic osteomyelitis, even with surgery. Amputation may be needed, especially in diabetics or other patients with poor blood circulation. The outlook is guarded in those who have an infection of a prosthesis.

Possible Complications

• Chronic osteomyelitis
• Local spread of infection
• Reduced limb or joint function
• Amputation

When to Contact a Medical Professional

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

Prevention

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.