What is the treatment for avascular necrosis?

Treatment of Avascular Necrosis

The treatment of avascular necrosis (AVN) should be stage-based, with early stages (I-II) managed with conservative measures and joint-preserving procedures like core decompression, while advanced stages (III-IV) typically require total joint arthroplasty for optimal outcomes in morbidity, mortality, and quality of life. 1

Diagnosis and Staging

• MRI is the preferred diagnostic method for AVN, especially in patients with normal radiographs but persistent hip pain 1
• CT imaging is valuable for surgical planning, showing the precise location and extent of necrotic lesions 2
• Staging is critical for treatment selection, with the Arlet and Ficat classification commonly used (stages I-IV) 3
• Asymptomatic disease with positive MRI findings occurs in approximately 5% of at-risk patients 1

Risk Factors

• Corticosteroid treatment is a major risk factor for AVN development 1, 4
• Other significant risk factors include alcohol abuse, hemoglobinopathies (including sickle cell disease), hyperlipidemia, and hypercoagulability states 1, 3
• HIV infection and antiretroviral therapy have been associated with increased risk of AVN 5

Treatment Algorithm Based on Stage

Early Stage AVN (Stages I-II: Pre-collapse)

• Conservative Management:

  • Protected weight-bearing with walking aids (canes or walkers) to reduce symptoms 1
  • NSAIDs and analgesics for symptomatic pain relief 1
  • Bisphosphonates may help prevent bone collapse in early stages 1

• Surgical Options:

  • Core decompression is the primary joint-preserving procedure for early-stage AVN 2, 6
  • Lesions involving <30% of the femoral head have <5% progression to collapse after core decompression 2, 6
  • Bone substitute filling may be added to core decompression to enhance structural support 4
  • 3D-printed guide plates can improve surgical precision during core decompression 2, 6
  • Protected weight-bearing is essential following core decompression to prevent fracture 2, 6

Advanced Stage AVN (Stages III-IV: Post-collapse)

• When femoral head collapse has occurred, joint replacement is typically necessary 1, 3
• For younger patients with specific anatomical abnormalities (dysplasia or varus/valgus deformity), osteotomy may be considered before proceeding to arthroplasty 1
• Cemented arthroplasty improves hip function and is associated with lower residual pain compared to uncemented arthroplasty, especially in elderly patients 1
• Total hip replacement is often required for end-stage disease with severe joint destruction 3

Special Considerations

• In pediatric patients with AVN, joint-preserving procedures should be prioritized whenever possible 4, 7
• For patients with sickle cell disease-related AVN, treatment options remain limited and challenging 8
• Regular radiographic follow-up is essential to monitor for disease progression or femoral head collapse after any treatment 2, 6

Emerging Treatments

• Mesenchymal stem cell therapy shows promise for improving outcomes in early-stage AVN, though still investigational 3
• Combination therapies that address both mechanical and biological factors may provide better outcomes than single modality treatments 3

Prognosis

• Late presentation is a major negative prognostic factor 1
• Untreated AVN inevitably leads to early degenerative joint disease 1
• AVN is estimated to cause up to one-third of all total hip arthroplasties performed in patients under 60 years of age 1
• Ten-year survivorship of the hip joint after appropriate joint-preserving treatment can reach 75% in carefully selected patients 7