What is the treatment for avascular necrosis?

Treatment of Avascular Necrosis

For early-stage avascular necrosis (pre-collapse), protected weight-bearing combined with core decompression and bone grafting is the treatment of choice, while late-stage disease with articular collapse requires total hip arthroplasty. 1

Stage-Based Treatment Algorithm

Pre-Symptomatic Disease (MRI Changes Only)

• Protected weight-bearing is the cornerstone of management when AVN is detected only on MRI without symptoms 1, 2
• Weight reduction and walking aids (canes or walkers) reduce mechanical stress on the affected joint 1, 2
• Bisphosphonates may prevent bone collapse and should be initiated to halt disease progression 1, 2
• Lesions involving less than 30% of the femoral head have less than 5% risk of progression to collapse, making conservative management particularly effective 1

Early-Stage Disease (Stage I-II, Pre-Collapse)

• Core decompression with bone substitute filling is the recommended surgical intervention, particularly in younger patients 1, 3
• This procedure achieves 92.3% success rates for Stage I disease and 54-100% for Stage IIA when strict non-weight-bearing is maintained postoperatively 4
• NSAIDs and analgesics provide symptomatic pain relief but do not alter disease progression 2
• Joint-preserving procedures such as osteotomy should be considered for young adults with symptomatic hip AVN, especially those with dysplasia or varus/valgus deformity 1, 2

Late-Stage Disease (Stage III-IV, Post-Collapse)

• Total hip arthroplasty is necessary once articular collapse has occurred 1, 5
• Cemented femoral fixation should be used in elderly patients with poor bone quality to reduce periprosthetic fracture risk 1, 2
• AVN causes up to one-third of all total hip arthroplasties in patients under 60 years of age 1, 2
• Surgical treatment of AVN gives less satisfactory results than treatment of primary osteoarthritis by similar procedures 6

Critical Diagnostic Considerations

• MRI is mandatory for diagnosis, especially when patients have persistent joint pain with normal radiographs 1, 2
• Both sides must be imaged as AVN is frequently bilateral 1, 2
• Initial radiography should exclude fracture, primary arthritis, or tumor before proceeding with MRI 2
• Approximately 5% of at-risk patients have asymptomatic disease detectable only on MRI 2, 7

Important Clinical Pitfalls

• Late presentation is a major negative prognostic factor and significantly worsens outcomes 1, 2
• Untreated AVN inevitably leads to early degenerative joint disease 1, 2
• Normal radiographs do not exclude AVN—MRI is required for early detection 7
• Strict non-weight-bearing compliance is essential after core decompression; non-compliance reduces success rates from 92.3% to 50% in Stage I disease 4
• There is no evidence-based consensus for managing osteonecrosis in pediatric patients, making treatment decisions more challenging in this population 1

Risk Factor Management

• Corticosteroid treatment is the most common risk factor and should be minimized or avoided when possible 2, 7
• Other major risk factors include alcohol abuse, hemoglobinopathies (sickle cell disease), hyperlipidemia, and hypercoagulability states 2
• HIV infection and antiretroviral therapy increase AVN risk, requiring heightened surveillance 2, 7
• In HIV-positive patients requiring corticosteroids, use the absolute minimum dose for the shortest duration possible (ideally <5 mg prednisone equivalent for <3 months) with concurrent bisphosphonate prophylaxis 7