How is Osteonecrosis diagnosed?

Osteonecrosis, also known as avascular necrosis, is a condition that occurs when there is a temporary or permanent loss of blood supply to the bones, leading to bone cell death. It commonly affects the hip joint, but can also occur in other joints such as the knee, shoulder, and ankle.

Diagnosing osteonecrosis involves a combination of medical history evaluation, physical examination, and diagnostic tests. The process aims to identify the underlying cause, determine the extent of bone damage, and guide appropriate treatment.

Medical history evaluation

During the medical history evaluation, the healthcare provider will ask about the patient's symptoms, their duration, and any factors that may contribute to osteonecrosis. This may include a discussion about previous injuries, use of medications (such as corticosteroids), alcohol consumption, and any underlying medical conditions.

Physical examination

A physical examination is performed to assess the affected joint and surrounding areas. The healthcare provider will look for signs of pain, limited range of motion, and any visible deformities. They may also check for muscle weakness or atrophy, as these can be associated with advanced stages of osteonecrosis.

Diagnostic tests

Imaging tests play a crucial role in diagnosing osteonecrosis. They help visualize the affected bone and determine the extent of damage. The most commonly used imaging techniques include:

• X-rays: X-rays can reveal changes in the bone structure, such as bone collapse or joint space narrowing. However, they may not detect early-stage osteonecrosis.


• Magnetic Resonance Imaging (MRI): MRI is highly sensitive in detecting osteonecrosis, even in its early stages. It provides detailed images of the bone and surrounding tissues, helping to assess the extent and location of the affected area.


• Computed Tomography (CT) scan: CT scans may be used to obtain more detailed images of the bone, especially in cases where MRI is contraindicated or inconclusive.

Blood tests are also commonly performed to help identify potential underlying causes of osteonecrosis. These tests may include:

• Complete Blood Count (CBC): CBC can help detect any abnormalities in the blood cell counts, which may indicate an underlying condition.


• Blood chemistry tests: These tests assess various markers in the blood, such as lipid levels, liver function, and blood glucose, which can provide insights into potential risk factors for osteonecrosis.


• Coagulation studies: Coagulation studies evaluate the blood's ability to clot and can help identify any clotting disorders that may contribute to osteonecrosis.

Once the diagnosis of osteonecrosis is confirmed, further tests may be required to determine the stage and severity of the condition. This information is crucial in guiding treatment decisions.