Osteomyelitis-diseases

Osteomyelitis is a pus-producing bone infection that can be acute or chronic. Although osteomyelitis often remains in one location, it can spread through the bone marrow and the membrane that covers the bones. Acute osteomyelitis is usually carried in the bloodstream. The condition most often affects rapidly growing children.

What causes it?

The disease usually starts with a small bruise that is affected by a major bacterial infection somewhere else in the body. The most common bacterium involved in osteomyelitis is Staphylococcus aureus, commonly called staph. Osteomyelitis strikes more children than adults, particularly boys who have a serious infection. The most common sites in children are the lower end of the thigh bone (femur), the upper end of the shin bone (tibia), the upper arm bone (humerus), and the forearm bone on the side of the thumb (radius). In adults, the most common sites are the pelvis and backbone, generally the result of contamination associated with surgery or injury.

Both forms of osteomyelitis are declining, except in drug abusers. With prompt treatment, the osteomyelitis that strikes children is cur­able. For the adult chronic type, the prognosis is still poor.

How it develops

Once Staphylococcus or a similar bacteria finds some damaged tissue, it multiplies and spreads directly to the bone. As the infection grows and produces pus within the bone, it cuts off the bone's blood supply, forms abscesses, and may kill the tissue. Tissue death stimulates the bone to create new abscesses and drainage, and the osteomyelitis may become chronic.

What are its symptoms?

Acute osteomyelitis starts abruptly, with sudden pain in the affected bone and tenderness, heat, swelling, and restricted movement over it. Other symptoms include irregular heartbeat, sudden fever, nausea, and general discomfort. Generally, chronic and acute osteomyelitis look the same, except that the chronic infection can recede and then flare up after a minor injury.

How is it diagnosed?

The doctor examines the person, asks about symptoms, and then orders blood tests to confirm osteomyelitis. X-rays may not show bone damage until the disease has been active for about 2 to 3 weeks. Bone scans can detect early infection. The diagnosis must rule out poliomyelitis, rheumatic fever, myositis, and bone fractures.

How is it treated?

The doctor usually starts antibiotic treatment for acute osteomyelitis even before the diagnosis is confirmed, and may prescribe large doses of intravenous penicillin, such as Nafcil or Bactocill.

Other treatments

If an abscess forms, treatment includes incision and drainage, culture of the drainage, and antibiotics. The drugs may be given orally, washed over the infected bone with a blood drainage system, or applied with antibiotic-soaked dressings.

Chronic osteomyelitis usually requires surgery to remove dead bone and to promote drainage. Even after surgery, the prognosis is poor, leaving the person in great pain or perhaps even needing amputation. Some doctors use hyperbaric oxygen to help the blood fight the infection and plastic surgery to repair damaged areas and increase blood supply.

What can a person with osteomyelitis do?

A person who is discharged from the hospital can carefully follow instructions related to wound care and must report signs of recurrent infection (increased temperature, redness, localized warmth, and swelling.) The person must also seek prompt treatment for possible sources of recurrent disease, such as boils, styes, blisters, and impetigo.