Avascular Necrosis of the Hip
Explanation of Diagnosis
The bones of the hip are living tissues that rely on a healthy blood supply for oxygen and nutrition. The hip joint functions as a ball-and-socket joint, and the femoral head (the ball portion) has a particularly delicate blood supply that can be disrupted by various acquired or inherited conditions.
When this blood supply is compromised, the bone within the femoral head begins to die — a process known as avascular necrosis (AVN) — and may eventually collapse.
Avascular necrosis can occur as a result of:
Hip trauma (e.g., fractures or dislocations)
Chronic alcohol use
Long-term corticosteroid use
Autoimmune conditions such as lupus
Blood disorders such as sickle-cell disease
How is Avascular Necrosis diagnosed?
Diagnosis begins with a detailed history and physical examination. The most common symptom is groin pain, which typically worsens over time. Patients may also experience difficulty walking and pain with prolonged sitting.
X-rays are used to assess the hip joint for early signs of bone collapse or joint space changes. However, MRI is the most sensitive imaging tool and can detect avascular necrosis before collapse occurs, allowing earlier diagnosis and treatment planning. MRI also helps determine the size and extent of the necrotic area.
Nonsurgical Treatment
Nonsurgical treatment is appropriate for patients who:
Have a small area of avascular necrosis with a low risk of collapse,
Have minimal pain, or
Are not suitable surgical candidates due to medical comorbidities.
Treatment options may include:
Activity modification and use of walking aids to reduce joint stress
Non-opioid pain management and anti-inflammatory medications
Bisphosphonates in select cases, under supervision from your general practitioner or medical specialist, to help preserve bone integrity
Surgical Treatment
Surgery is recommended for patients with symptomatic avascular necrosis that has either collapsed or is at high risk of collapse.
Surgical procedures can be divided into two categories:
Hip Preservation Procedures:
These are suitable for cases where the femoral head has not yet collapsed. Options include:Core decompression – drilling into the necrotic bone to improve blood flow.
Bone grafting – replacing diseased bone with healthy graft material to promote healing and structural support.
Hip Reconstruction (Hip-Sacrificing) Procedures:
When the femoral head has already collapsed and cannot be preserved, a total hip replacement is the preferred treatment. This procedure replaces the damaged bone and cartilage with artificial components, relieving pain and restoring mobility.
