Diagnosing Osteomyelitis

NYU Langone physicians are experienced in diagnosing bone infections, also known as osteomyelitis.

To diagnose a bone infection, doctors first perform a physical exam, looking for any open wounds or areas of tenderness, swelling, and redness. They may ask if you’ve had any recent infections, physical trauma, or surgery, or if you have experienced any pain or decreased range of motion in the affected limb.

Your doctor may also order tests to look for the presence of bacteria and assess the extent of the condition.

Blood Tests

Doctors may use blood tests to determine whether you have an infection. The only way to determine what type of bacteria is causing an infection is with a tissue or fluid sample culture. Information from these tests can help the doctor select the most effective antibiotic.

Vital signs and certain blood tests are also used to detect sepsis, a systemic response to an infection that leads to low blood pressure and increased heart rate. This potentially life-threatening complication can reduce blood flow to major organs and body systems, such as the lungs, kidneys, liver, and central nervous system, causing them to shut down.

X-rays

X-rays use electromagnetic radiation to create pictures of the skeleton, called plain radiographs. These images may be used to identify the exact location of an infection. X-rays are also used to look for any changes in the bone that may indicate a chronic infection.

MRI Scans

To better view the structure of a bone or the soft tissues, such as cartilage and muscle, a doctor may order an MRI scan, which uses a magnetic field and radio waves to create computerized, three-dimensional images of structures in your body.

Before the test, the doctor may inject a contrast dye into your vein. This dye helps enhance the MRI image.

CT Scans

A CT scan uses X-rays and a computer to create detailed, three-dimensional, cross-sectional images of your tissues and internal organs. A CT scan may reveal bone damage caused by an infection.

Your doctor may inject a contrast agent into a vein to enhance the quality of the image.

Bone Scans

The doctor may recommend a bone scan instead of an MRI scan if you have a medical implant, such as a pacemaker, which may affect the magnets in the scanner.

During a bone scan, the doctor injects a radioactive substance called a tracer into a vein in your arm. The tracer travels through your bloodstream and into your bones, where it is absorbed by areas that are growing more rapidly. A specialized camera that’s similar to an X-ray machine takes pictures of the tracer.

Areas of bone growth or repair show up as bright spots on the image. This can indicate an infection. If the scan is positive, further testing is required.

Tissue Cultures

Doctors may perform a tissue culture to determine the type of bacteria or germ causing the infection. The doctor removes some fluid from a wound over an infected bone. Alternatively, the doctor may take a tissue sample from within the infected bone. The doctor sends this specimen to a laboratory for examination.

To obtain a tissue sample, the doctor removes a piece of tissue from an infected bone. This is done by surgically cutting and removing a sample of tissue or extracting the tissue using a needle.

These procedures are usually performed in an operating room, and patients may be given a sedative to help them relax.

Bone Biopsies

After identifying a bone infection through imaging studies, your doctor may biopsy the affected area to determine which bacteria are involved and to choose the best course of treatment. During the procedure, which is similar to a tissue culture, a doctor removes a sample from the affected area. Bone biopsies are usually performed in an operating room and may be done at the same time as a tissue culture.

Doctors may also perform a bone biopsy if they suspect that you have an infection that isn’t showing up clearly on imaging tests. Looking at a bone biopsy under a microscope can also help doctors assess the overall viability of the involved bone.