Osteomyelitis
Osteomyelitis is one of the world’s oldest known diseases, first described in human patients by Hippocrates, who lived between 460–370 BC. The disease involves a swelling of bone tissue, most often due to a bacterial or fungal infection. Normally, bone tissue is highly resistant to infection. Osteomyelitis occurs when germs enter the bone, either directly from an injury or by spreading from an infection elsewhere in the body. Left untreated, osteomyelitis may result in permanent destruction of bone and surrounding tissues and can even lead to amputation.
Types of Osteomyelitis
Osteomyelitis can occur in any bone. In children, the long bones of the arms and legs are most often affected, while osteomyelitis most often affects the bones of the feet, spine and hips in adults. There are three main types based on the duration of infection. They include:
- Acute osteomyelitis, a new infection of the bone that develops rapidly
- Subacute osteomyelitis, a new infection that develops slowly
- Chronic osteomyelitis, a persistent, severe bone infection that usually develops after an episode of acute osteomyelitis that has not been fully cured.
- Chronic osteomyelitis may appear to have been successfully treated, then recur after a symptom-free period of weeks or months.
Osteomyelitis is further classified by these routes of infection:
- hematogenous osteomyelitis, which spreads to the bone through the bloodstream
- contiguous osteomyelitis, which spreads to bone from infected tissue nearby
- direct inoculation osteomyelitis, in which germs enter the bone at the site of surgery or injury
- vascular insufficiency osteomyelitis, which occurs when an open sore — most commonly a diabetic foot ulcer — festers due to poor blood circulation
Causes of Osteomyelitis
Osteomyelitis most often involves infection with staphylococcus aureus bacteria, a germ found on the skin. It may also be caused by funguses or other germs. Common sources of bone infection include:
- abscessed tooth
- bone fracture
- ear infection
- infection of soft tissues
- poor blood circulation due to diabetes
- sinus infection
- surgery involving the bones
- trauma, such as a puncture wound or other injury
Signs and Symptoms of Osteomyelitis
Symptoms vary depending on the type and location of the infection, and may include:
- bone pain
- fever and chills
- general feeling of being unwell
- pus drainage from traumatic or surgical wound
- swelling, redness and warmth at the site of infection
How Is Osteomyelitis Diagnosed?
In addition to physical examination and review of symptoms, diagnostic procedures may include:
- biopsy of affected bones
- blood tests
- imaging studies such as a bone scan, CT scan, MRI or X-ray
Treatments for Osteomyelitis
With early diagnosis and prompt treatment, it is possible to cure osteomyelitis. The goal of treatment is to eliminate the infection and minimize bone loss. Initial treatment options may include:
- antibiotic or antifungal drugs given by mouth or IV for 4 to 8 weeks
- surgical drainage and cleaning of the affected area
Depending on the severity and extent of infection, more intensive treatment may be needed, such as:
- antibiotic or fungal drug therapy continued for several months
- bone graft following surgical removal of damaged tissue
Chronic osteomyelitis, especially due to inadequate blood flow, can be difficult to treat because impaired flow can prevent antibiotics from working as well as they should. In these cases, therapies to aid wound healing may be used, such as:
- hyperbaric oxygen therapy
- negative pressure wound therapy, also called vacuum-assisted closure