What is osteomyelitis?

Osteomyelitis is an inflammation or swelling of bone tissue. It’s most often caused by an infection. Bone infection may occur for many reasons. It can affect children or adults.

What causes osteomyelitis?

Osteomyelitis can be caused by a bacterial infection of the blood. This is sometimes called bacteremia or sepsis. This infection can spread to the bone. It’s most common in babies and children. It usually affects their long bones such as the thighbone or upper arm bone. In adults, it often affects the bones in the spine. The source of the blood infection is usually Staphylococcus aureus. But it may be caused by other germs.

Other causes include:

  • An injury or surgery
  • Frequent medicine injections
  • Diabetes
  • A weak immune system (such as HIV or getting cancer treatment)
  • A prosthetic device

Osteomyelitis can have a sudden start, a slow and mild start, or may be a chronic problem. This depends on the source and cause of the infection.

Who is at risk for osteomyelitis?

Osteomyelitis can affect anyone. But, it is more common in babies, children, and older adults. People at greater risk include those with a weak immune systems, recent injury or surgery, or diabetes.

What are the symptoms of osteomyelitis?

Symptoms of osteomyelitis vary, depending on the cause and whether it starts quickly or slowly. These are the most common:

  • A new limp
  • A stiff back, if the spine is affected
  • Feeling ill
  • Fever (high fever with blood infection)
  • Irritability
  • Lethargy or fatigue
  • Weight loss
  • Pain in the affected area
  • Redness in the affected area
  • Swelling of the affected area
  • Trouble bearing weight or walking
  • Trouble moving joints near the affected area
  • Warmth in the affected area

The symptoms of osteomyelitis may look like other medical conditions or problems. Always talk with your healthcare provider for a diagnosis.

How is osteomyelitis diagnosed?

Your healthcare provider will review your medical history and give you a physical exam. You may have tests. These may include:

  • Blood tests, such as:
    • Complete blood count (CBC). This test measures the size, number, and maturity of blood cells. It’s done to check for increased white blood cells that may signal an infection.
    • Erythrocyte sedimentation rate (ESR). This test measures 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. They fall and settle faster at the bottom of the test tube. The faster the blood cells fall, the more severe the inflammation.
    • C-reactive protein (CRP). This is a blood test to help find inflammation or an infection.
    • Blood culture. This is a blood test that looks for bacteria or other germs in the blood.
  • Needle aspiration or bone biopsy. A small needle is inserted into the affected area to take a tissue biopsy.
  • X-ray. This test uses invisible electromagnetic energy beams to make images of tissues, bones, and organs onto film.
  • Radionuclide bone scans. Pictures or X-rays are taken of the bone after a dye is injected and absorbed by the bone tissue. These are used to find tumors, infection and bone abnormalities.
  • CT scan. This test uses X-rays and a computer to make 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.
  • MRI. This test uses large magnets, radiofrequencies, and a computer to make detailed images of organs and structures in the body.
  • Ultrasound. This test uses high frequency sound waves and a computer to make images of blood vessels, tissues, and organs. Ultrasounds are used to view organs as they work, and to check blood flow through blood vessels.