What is the latest evidence-based management for avascular necrosis of the hip?

Evidence-Based Management of Avascular Necrosis of the Hip

The most effective evidence-based management for avascular necrosis (AVN) of the hip involves early intervention with core decompression combined with biotechnologies for pre-collapse stages, while total hip replacement remains the definitive treatment for advanced disease with femoral head collapse. 1, 2

Diagnosis and Staging

• Magnetic resonance imaging (MRI) is the preferred diagnostic method for AVN of the hip, especially in patients presenting with persistent hip pain with normal standard radiologic studies 3
• Both sides of the hip should be imaged, as AVN can be bilateral 3
• Staging is critical for treatment selection, with pre-collapse stages (Ficat and Arlet stages 1-3) being amenable to joint-preserving procedures 4

Non-Surgical Management

• Non-surgical management has a very limited role in AVN treatment and is only appropriate in the earliest stages 1
• Weight reduction and use of walking aids (canes or walkers) may help reduce symptoms in early stages 5
• Pharmacological treatments that have been investigated include:
  • Bisphosphonates to prevent bone collapse 3
  • Anticoagulants to improve blood flow 4
  • Statins to promote angiogenesis 4

Surgical Management

Pre-Collapse Stages (Early AVN)

• Core decompression (CD) is the most widely used procedure for early-stage AVN before femoral head collapse 4, 2

  • Traditional single-tunnel technique uses a cannulated drill bit inserted into the lateral cortex of the proximal femur 2
  • Multiple small drilling technique has been developed to decrease fracture risk 2

• Enhanced core decompression with biologics shows promising results:

  • Autologous bone marrow aspirate concentrate (BMAC) 1, 2
  • Platelet-rich plasma (PRP) delivered through a trocar to saturate the necrotic area 6
  • Mesenchymal stem cells to enhance bone repair 1, 2
  • Demineralized bone matrix or bone morphogenetic proteins 1
  • Tantalum rod insertion for structural support 2

• Arthroscopic approaches allow:

  • Visual control for precise localization and treatment of the necrotic area 6
  • Preservation of cartilage integrity 6
  • Diagnosis and treatment of associated labral or cartilage pathology 6

Post-Collapse Stages (Advanced AVN)

• Total hip replacement (THR) is the most reliable treatment option for advanced AVN with femoral head collapse 4
• For young adults with symptomatic hip AVN, especially with dysplasia or varus/valgus deformity, joint-preserving procedures such as osteotomy may be considered 5
• For elderly patients with poor bone quality, cemented femoral fixation should be considered to reduce periprosthetic fracture risk 5

Treatment Algorithm Based on Stage

1. Stage I (Pre-radiographic):

   • Core decompression with biological augmentation (BMAC, PRP, or stem cells) 1, 2, 6

2. Stage II (Pre-collapse with visible lesion):

   • Core decompression with biological augmentation and structural support (bone grafting or tantalum rod) 1, 2

3. Stage III (Early collapse):

   • Limited core decompression with extensive biological augmentation 1
   • Consider osteotomy in young patients with small lesions 5

4. Stage IV (Advanced collapse with secondary osteoarthritis):

   • Total hip replacement 4

Special Considerations

• Pediatric oncology patients with AVN may benefit from core decompression with bone substitute filling 7

• Secondary causes of AVN should be investigated and treated accordingly:

  • Steroid use (common in oncology patients) 7
  • Alcohol consumption 4
  • Hemoglobinopathies 4
  • Coagulation disorders 4

• Patients should be monitored regularly with follow-up imaging to assess disease progression and treatment response 1