Infection of bone is known as osteomyelitis (OM). It develops typically due to infections caused by bacteria, fungi or other pathogens that can easily circulate through the bloodstream. Infections not only cause the death of bone tissue but also affect surrounding soft tissues like muscles, tendons and connective tissue. Common symptoms include pain in the bones, with local swelling or redness.
Osteomyelitis is equally frequent in children and adults. While children may develop infection in the long bones of legs and arms, in adults usually the bones of vertebra are affected. Once considered as an incurable ailment, osteomyelitis can be successfully treated. A strong dose of antibiotics or surgical removal of dead bone tissue effectively controls OM.
Common symptoms of OM include:
- Pain in the infected bone at rest that worsens with movement
- Local swelling, redness, and warmth
- Fever, chills and excessive sweating
- Malaise and lethargy
An intense bone pain along with high fever, without any other symptoms, may be an indication of osteomyelitis and a doctor should be consulted immediately. Diabetics may also present with diabetic ulcers on the ankle and feet. At times osteomyelitis appears without any signs or symptoms. However, when left unattended osteomyelitis becomes resistant to treatment and may cause recurrent infections of the soft tissue like muscles, over bones.
Bones become infected mainly by three possible ways:
- Through the bloodstream – blood can carry pathogens from other infected part of body to the bone. However, not all but only a specific region of bone gets infected. For example, children develop OM commonly in the soft growth plates, present at the ends of the long bones of the arms and legs.
- Direct infection – in case of severe bone injury, when a part of the bone protrudes out from the skin, it may directly contract an infection. Direct infection also occurs during surgeries, while replacing joints or repairing fractures. Continuous infection causes local accumulation of pus (abscess) that keeps draining through the skin.
- From a nearby infected tissue – Infection from a surrounding soft tissue like muscle may spread to the bone. However, the spread of infection usually takes a few days to weeks. It particularly affects elderly people.
Bones swell upon getting infected and start compressing the blood vessels in the marrow. This limits or cuts off the blood supply to the bone, causing a part of the infected area to die. The dead areas are often impervious to antibodies or antibiotics. Individuals, undergoing kidney dialysis and those requiring regular injections are at higher risk of developing osteomyelitis.
Treatment of osteomylitis primarily aims at treating the infected area of bone. Occasionally, surgical removal of the infected or dead tissue becomes necessary.
After detecting the pathogen, suitable antibiotic is suggested to treat the infection. The antibiotics are usually administered intravenously (IV) for at least six weeks. Nausea and vomiting may appear as common side effect of these drugs.
Depending on the severity of the infection, surgical methods are adopted when antibiotics fail to work:
- Draining the infected area
- Removing infected bone and surrounding tissue
- Restoring blood flow to the bone
In terminal cases, the affected limb is amputated to prevent the further spread of infection.