Orthopaedic doctors most often diagnose AVN. After performing a complete physical exam and asking about the patient's medical history (for example, what health problems the patient has had and for how long), the doctor may use one or more imaging techniques to diagnose AVN. As with many other diseases, early diagnosis increases the chances of treatment success.
Diagnostic tests are used to determine the amount of bone affected and how far the disease has progressed. It is likely that the doctor first will recommend a radiograph, commonly called an x ray. X rays can help identify many causes of joint pain, such as a fracture or arthritis. If the x ray is normal, the patient may need to have more tests. Research studies have shown that magnetic resonance imaging, or MRI, is the most sensitive method for diagnosing avascular necrosis in the early stages.
Other diagnostic tests include:
- Bone Scan: A bone scan also known as bone scintigraphy are used most commonly in patients who have normal x rays.
- Computerized Tomography: A CT scan is an imaging technique that provides the doctor with a three-dimensional picture of the bone.
- Biopsy: A biopsy is a surgical procedure in which tissue from the affected bone is removed and studied.
- Functional Evaluation of Bone: These tests are sensitive for detecting increased pressure within the bone, but they require surgery. These tests may be used when AVN is suspected, despite normal results of x rays, bone scans, and MRIs.