What is the treatment for vascular necrosis (also known as avascular necrosis)?

Treatment of Avascular Necrosis

The treatment of avascular necrosis requires early intervention with a staged approach based on disease severity, with core decompression being the primary surgical intervention for early-stage disease, while advanced cases require joint replacement surgery.1

Understanding Avascular Necrosis

Avascular necrosis (AVN), also called osteonecrosis, is defined as bone death due to inadequate vascular supply. It commonly affects:

• Femoral head (most common)
• Humeral head
• Tibial metadiaphysis
• Femoral metadiaphysis
• Scaphoid
• Lunate
• Talus

Risk factors include:

• Trauma
• Corticosteroid therapy
• Alcohol use
• HIV infection
• Blood disorders
• Chemotherapy/radiation
• Gaucher disease
• Caisson disease

Diagnostic Approach

Early diagnosis is crucial to prevent articular collapse and joint destruction. The diagnostic workup includes:

• MRI (most sensitive for early detection)
• CT scan
• X-rays (less sensitive for early disease)
• Bone scans

Treatment Algorithm Based on Disease Stage

1. Early Stage (Pre-collapse, ARCO 1-2)

• Non-surgical options:

  • Protected weight-bearing
  • Physical therapy
  • Pharmacological interventions:
    • Bisphosphonates
    • Statins
    • Anticoagulants
    • Iloprost (vasoactive prostaglandin analogue) 2

• Surgical options:

  • Core decompression (primary surgical intervention)
  • Core decompression with bone marrow aspirate
  • Vascular fibular grafting

2. Advanced Stage (Post-collapse, ARCO 3-4)

• Surgical options:
  • Resurfacing hemiarthroplasty
  • Total joint arthroplasty (for severe secondary osteoarthritis)
  • For talar AVN: talar resection/replacement or tibiotalar joint fusion 1

Treatment Efficacy by Location

Femoral Head AVN

• Core decompression shows better results in early stages
• 71% of ARCO stage 3 and 100% of ARCO stage 4 cases ultimately require total joint replacement 2
• Femoral head AVN accounts for 10% of total hip replacements in the United States 1

Other Locations

• Humeral head: Core decompression for early stages; total shoulder arthroplasty for advanced disease
• Talus: Core decompression for early stages; talar resection/replacement or fusion for advanced disease

Special Considerations

Sickle Cell Disease

Evidence suggests that adding hip core decompression to physical therapy does not achieve significant clinical improvement compared to physical therapy alone in sickle cell patients with AVN 3. However, this conclusion is based on limited evidence with high attrition rates.

Cemented vs. Uncemented Arthroplasty

For patients requiring arthroplasty, cemented arthroplasty improves hip function and is associated with lower residual pain postoperatively compared to uncemented arthroplasty 1.

Pitfalls and Caveats

1. Delayed diagnosis: X-rays are not sensitive in early stages of AVN, requiring a high level of suspicion and advanced imaging 4

2. Timing of intervention: Surgical outcomes are significantly better when performed before femoral head collapse occurs

3. Bilateral involvement: In non-traumatic cases, femoral head AVN is often bilateral (70-80%), requiring evaluation of both sides 1

4. Necrotic volume assessment: Femoral heads with necrotic volume >30% have a 46-83% risk of collapse, compared to <5% risk when necrotic volume is <30% 1

5. Monitoring for progression: Regular follow-up with imaging is essential as the disease can progress rapidly despite treatment