What is osteomyelitis?

Osteomyelitis is an inflammation or swelling of bone tissue that is usually the result of an infection. Bone infection may occur for many different reasons and can affect children or adults. Some of the causes of osteomyelitis include the following:

  • Osteomyelitis may occur as a result of a bacterial bloodstream infection, sometimes called bacteremia, or sepsis, that spreads to the bone. This type is most common in infants and children and usually affects their long bones such as the femur (thighbone) or humerus (upper arm bone). When osteomyelitis affects adults, it often involves the vertebral bones along the spinal column. The source of the blood infection is usually Staphylococcus aureus, although it may be caused by a different type of bacteria or fungal organism.

  • Osteomyelitis can also occur from a nearby infection due to a traumatic injury, frequent medication injections, a surgical procedure, or use of a prosthetic device. In addition, individuals with diabetes who develop foot ulcers are more susceptible. In any of these situations, the organism has a direct portal of entry into the affected bone.

  • Individuals with weakened immune systems are more likely to develop osteomyelitis. This includes individuals with sickle cell disease, HIV, or individuals receiving immunosuppressive medications, such as chemotherapy or steroids.

Osteomyelitis can have a sudden onset, a slow and mild onset, or may be a chronic problem, depending on the source of the infection.

Who is affected by osteomyelitis?

Osteomyelitis can affect all populations, but is more common in infants, children, and older adults. Populations at increased risk include individuals with weakened immune systems, recent trauma, or diabetes.

What are the symptoms of osteomyelitis?

Symptoms of osteomyelitis vary, depending on the cause and whether it is a rapid or slow onset of infection. The following are the most common symptoms of osteomyelitis. However, each individual may experience symptoms differently. Symptoms may include:

  • Fever (The fever may be high when osteomyelitis occurs as the result of a blood infection.)

  • Pain and tenderness in the affected area

  • In infants who cannot express pain, irritability may be present

  • Irritability

  • Feeling ill

  • Swelling of the affected area

  • Redness in the affected area

  • Warmth in the affected area

  • Difficulty moving joints near the affected area

  • Difficulty bearing weight or walking

  • A new limp

  • A stiff back (with vertebral involvement)

The symptoms of osteomyelitis may resemble other medical conditions or problems. Always consult your doctor for a diagnosis.

How is osteomyelitis diagnosed?

In addition to a complete medical history and physical examination, diagnostic procedures for osteomyelitis may include the following:

  • Blood tests, including the following:

    • Complete blood count (CBC). A measurement of size, number, and maturity of the different blood cells in a specific volume of blood; to check for increased white blood cells that may signal an infection in the body.

    • Erythrocyte sedimentation rate (ESR). A measurement of how quickly red blood cells fall to the bottom of a test tube. When swelling and inflammation are present, the blood's proteins clump together and become heavier than normal. Thus, when measured, they fall and settle faster at the bottom of the test tube. Generally, the faster the blood cells fall, the more severe the inflammation.

    • C-reactive protein (CRP). A blood test to help detect the presence of inflammation or an infection.

  • Needle aspiration or bone biopsy. A small needle is inserted into the abnormal area in almost any part of the body, guided by imaging techniques, to obtain a tissue biopsy. This type of biopsy can provide a diagnosis without surgical intervention.

  • X-ray. A diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.

  • Radionuclide bone scans. Pictures or X-rays taken of the bone after a dye that is absorbed by bone tissue has been injected. These are used to detect tumors and bone abnormalities.

  • Computed tomography scan (also called CT or CAT scan). A diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce horizontal, or axial, images (often called slices) of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general X-rays.

  • Magnetic resonance imaging (MRI). A diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.

  • Ultrasound. A diagnostic technique that uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. Ultrasounds are used to view internal organs as they function, and to assess blood flow through various vessels.

Treatment for osteomyelitis

Specific treatment for osteomyelitis will be determined by your doctor based on:

  • Your age, overall health, and medical history

  • Extent of the condition

  • Your tolerance for specific medications, procedures, and therapies

  • Expectation for the course of the condition

  • Your opinion or preference

The goal for treatment of osteomyelitis is to cure the infection and minimize any long-term complications. Treatment may include:

  • Medications. Administration of intravenous (IV) antibiotics, which may require hospitalization or may be given on an outpatient schedule, may be necessary. Intravenous or oral antibiotic treatment for osteomyelitis may be very extensive, lasting for many weeks.

  • Monitoring of successive X-rays and blood tests

  • Pain management

  • Bed rest (or restricted movement of the affected area)

  • Surgery. In some cases, surgical intervention may be necessary to drain infectious fluid, or to remove damaged tissue and bone.

Long-term considerations for osteomyelitis

Osteomyelitis requires long-term care to prevent further complications, including care to prevent the following:

  • Fractures of the affected bone

  • Stunted growth in children (if the infection has involved the growth plate)

  • Gangrene infection in the affected area