Avascular necrosis (AVN)
Avascular Necrosis (AVN): Understanding the Condition
Avascular necrosis (AVN), also known as osteonecrosis or bone infarction, is a condition that occurs when bone tissue dies due to a lack of blood supply512. Early on, there may be no symptoms, but gradually joint pain may develop, which may limit the person’s ability to move5. Complications may include collapse of the bone or nearby joint surface5.
Causes and Risk Factors
AVN is primarily caused by the disruption of blood flow to the bone2. This can result from various factors, including:
- Bone fractures and joint dislocations5
- Alcoholism5
- High-dose steroid use52
- Certain medical conditions such as pancreatitis, diabetes, Gaucher’s disease, HIV, systemic lupus erythematosus, and sickle cell anemia2
- In some cases, the cause of disrupted blood supply is unknown2
Symptoms
In the early stages of AVN, some people may not experience any symptoms81. However, as the condition progresses, symptoms may include1:
- Mild to moderate hip or groin pain
- Pain while walking or when moving the hip, possibly radiating down to the knee
- Stiffness in the hip joint
- Trouble putting weight on one leg, often causing a limp
- Joint pain and discomfort that increases over time5
Diagnosis
Diagnosis of AVN typically involves a combination of medical history review, physical examination, and imaging tests15.
- Physical Exam: A doctor will inquire about medical history, including injuries and occupation1. They will also assess hip movement to pinpoint pain and range of motion1.
- Imaging Tests:
Treatment
The goal of treatment is to prevent further bone loss3. Treatment options vary depending on the stage and severity of AVN.
- Medications:
- Nonsteroidal anti-inflammatory drugs (NSAIDs) may help relieve pain73.
- Cholesterol-lowering drugs may help prevent blood vessel blockages3.
- Blood thinners may prevent clots in blood vessels3.
- Osteoporosis drugs might slow progression, but evidence is mixed3.
- Therapy:
- Restricting physical activity or using crutches to keep weight off the joint34.
- Exercises to maintain or improve the range of motion in the joint43.
- Surgical and Other Procedures:
- Core decompression involves removing part of the inner layer of bone to reduce pain and promote new blood vessel growth34.
- Bone transplant (graft) can strengthen the affected area3.
- Joint replacement may be necessary if the bone has collapsed or other treatments aren’t helping3.
