Avascular Necrosis
Avascular necrosis (AVN), also called osteonecrosis, is the death of bone tissue due to loss of blood supply. Without adequate blood flow, the bone cells die and the bone structure collapses over time. The femoral head — the ball of the hip joint — is the most commonly affected site, but the knee, shoulder, and ankle can also be involved. AVN ranges from early-stage disease with no collapse (often manageable with joint-preserving procedures) to late-stage collapse requiring joint replacement.
Find a Specialist
Symptoms
- Groin pain that comes on gradually, often without a clear injury
- Pain that worsens with weight bearing and activity
- Limited range of hip motion
- Pain at night in more advanced stages
- Limping to offload the affected hip
When to See a Doctor
See an orthopaedic specialist promptly if you have risk factors (corticosteroid use, alcohol use, prior hip trauma, sickle cell disease, or history of decompression sickness) and develop hip or groin pain. Early-stage AVN is detected on MRI before collapse — and early intervention preserves more options. Once the bone collapses, joint-preserving treatments become less effective.
Treatment Options
Activity modification and protected weight bearing
For early small lesions in non-weight-bearing areas of the femoral head. Crutches to reduce load while the area is monitored.
Core decompression
A drill is passed into the femoral head to reduce intraosseous pressure and stimulate new blood vessel growth. Most effective in early stages before collapse. Often combined with bone graft or stem cell therapy.
Bone grafting and vascularized fibula
For patients with pre-collapse disease: a vascularized bone graft (often from the fibula) is implanted to provide structural support and a new blood supply. Complex procedure with variable outcomes.
Total hip replacement
For patients with femoral head collapse and pain. The standard treatment for late-stage AVN. Highly effective at relieving pain and restoring function.
Recovery Timeline
Depends entirely on stage. Core decompression: 6-8 weeks on crutches, 3-6 months for full recovery. Total hip replacement for collapsed AVN: 3-6 months for full recovery. Early intervention consistently produces better outcomes.
Frequently Asked Questions
What causes avascular necrosis?
The most common causes are high-dose corticosteroid use (even short courses) and heavy alcohol consumption, which account for about 80% of non-traumatic AVN. Traumatic AVN follows hip fractures or dislocations that disrupt blood flow. Other associations include sickle cell disease, lupus, radiation therapy, and Gaucher disease. In about 20% of cases, no cause is identified.
Is avascular necrosis curable?
Small, early lesions can sometimes stabilize on their own or with core decompression. Most patients with significant femoral head involvement eventually progress to collapse without intervention. Once the bone collapses and the joint surface is damaged, the practical treatment is hip replacement — the joint cannot regenerate.
Can avascular necrosis affect both hips?
Yes. Bilateral AVN occurs in 40-80% of patients with steroid- or alcohol-related disease. If you are diagnosed with AVN in one hip, your surgeon should evaluate the other hip with MRI as well, since early asymptomatic disease in the other hip changes the management plan.
Related Specialty
Hip Specialists →Avascular Necrosis by State
Related Conditions
This information is for educational purposes only and is not a substitute for professional medical advice. Always consult a qualified healthcare provider for diagnosis and treatment.