What is the management approach for avascular necrosis of the hip?

Management of Avascular Necrosis of the Hip

Surgical intervention is necessary for disabling symptoms in avascular necrosis (AVN) of the hip as there is no accepted medical therapy for this condition. 1

Diagnostic Approach

• MRI is the preferred diagnostic method for AVN of the hip, especially in patients with persistent hip pain but normal radiographs 2
• Both hips should be imaged as AVN can present bilaterally 2
• CT scan can also be used for diagnosis when MRI is performed in response to patient complaints of hip or spine pain 1
• Asymptomatic disease with positive MRI findings occurs in approximately 5% of at-risk patients 1

Risk Factors and Etiology

• Common risk factors include:
  • Corticosteroid treatment 1, 3
  • Alcohol abuse 1, 3
  • Hemoglobinopathies (including sickle cell disease) 1, 3
  • Hyperlipidemia 1, 3
  • Hypercoagulability states 1
• In pediatric and adolescent populations, trauma is a commonly recognized cause 4, 5
• In oncology patients, AVN is often linked to high doses of oral and intravenous corticosteroids and extended therapy duration 5

Non-Surgical Management (Early Stages)

• Weight reduction and use of walking aids (canes or walkers) to reduce symptoms 2
• Bisphosphonates may help prevent bone collapse in early stages 2, 6
• Non-surgical management has very limited role and is only appropriate in the earliest stages of AVN 6

Surgical Management Algorithm

Early Stages (Ficat and Arlet Stage I and II - before articular surface collapse)

• Core decompression (CD) is the most common procedure 6, 5
• Enhanced CD techniques include combining with:
  • Autologous bone-marrow cells 6, 5
  • Demineralized bone matrix 6
  • Bone morphogenetic proteins 6
  • Bone substitute filling 5
• For young adults with symptomatic hip AVN, especially with dysplasia or varus/valgus deformity, joint-preserving procedures such as osteotomy may be considered 2

Advanced Stages (Ficat and Arlet Stage III and IV - after articular surface collapse)

• Total hip arthroplasty is the main treatment 3
• For elderly patients with poor bone quality, cemented femoral fixation should be considered to reduce periprosthetic fracture risk 2

Prognosis and Outcomes

• 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
• In patients suitable for joint preservation procedures, 10-year survivorship of the hip joint can reach 75% 7

Monitoring and Follow-up

• Regular imaging follow-up is essential to monitor disease progression 4
• The most serious complication of treatment is iatrogenic avascular necrosis 1
• Physical therapy should be incorporated into the treatment plan to improve joint function 5

Emerging Therapies

• Tissue engineering strategies combining biomaterials, stem cells, and growth factors offer potential future treatments 4
• Injectable systems that can provide mechanical support to the collapsing femoral head could potentially reduce the need for surgical interventions 4
• Mesenchymal stem cell therapies show promise for improving the functional prognosis of the disease 3