How is osteomyelitis diagnosed?
To diagnose osteomyelitis, the doctor will first perform a history, review of systems, and a complete physical examination. In doing so, the physician will look for signs or symptoms of soft tissue and bone tenderness and possibly swelling and redness. The doctor will also ask you to describe your symptoms and will evaluate your personal and family medical history. The doctor can then order any of the following tests to assist in confirming the diagnosis:
- Radiographs (X-Rays): These tests can show abnormalities of the bone. The abnormalities can include a focal decrease in density, which can suggest bone destruction from bacteria. It can also demonstrate an area where infected bone can be trapped by a bacterial infection.
- Magnetic Resonance Imaging (MRI): This imaging examination can show any fluid in the bone with greater sensitivity and precision. It is a helpful tool to see how far the infection has spread, if present.
- Blood tests: When testing the blood, measurements are taken to confirm an infection: a CBC (complete blood count), which will show if there is an increased white blood cell count; an ESR (erythrocyte sedimentation rate); and/or CRP (C-reactive protein) in the bloodstream, which detects and measures inflammation in the body.
- Blood culture: A blood culture is a test used to detect bacteria that has escaped into the bloodstream. A sample of blood is taken and then placed into an environment that will support the growth of bacteria. By allowing the bacteria to grow, the infectious agent can then be identified and tested against different antibiotics in hopes of finding the most effective treatment.
- Needle aspiration: During this test, a needle is used to remove a sample of fluid and cells from the vertebral space, or bony area. It is then sent to the lab to be evaluated by allowing the infectious agent to grow on media.
- Biopsy: A biopsy (tissue sample) of the infected bone may be taken and tested for signs of an invading organism.
- Bone scan: During this test, a small amount of Technetium-99 pyrophosphate, a radioactive material, is injected intravenously into the body. If the bone tissue is healthy, the material will spread in a uniform fashion. However, a tumor or infection in the bone will absorb the material and show an increased concentration of the radioactive material, which can be seen with a special camera that produces the images on a computer screen. The scan can help your doctor detect these abnormalities in their early stages, when X-ray findings may only show normal findings.