Is Magnetic Field Therapy (MAHT) effective for treating Avascular Necrosis (AVN)?

Magnetic Field Therapy (MAHT) for Avascular Necrosis

Magnetic field therapy is not supported by current evidence-based guidelines for the treatment of avascular necrosis and should not be used as a primary or adjunctive treatment modality.

Current Evidence-Based Treatment Approaches

The available guideline evidence does not mention magnetic field therapy as a treatment option for AVN. Instead, established management strategies are recommended based on disease stage:

Early-Stage AVN (Pre-collapse, Ficat Stage I-II)

Conservative Management:

• Protected weight-bearing is the cornerstone of early management for patients with pre-symptomatic AVN showing only MRI changes 1, 2
• Weight reduction and walking aids (canes or walkers) help reduce symptoms in early stages 1, 2
• Bisphosphonates may prevent bone collapse in early stages 1

Surgical Interventions for Early Disease:

• Core decompression with bone substitute filling is recommended for early-stage disease, particularly in younger patients 1, 3
• This procedure is pain-relieving, head-preserving, and improves hip function in Ficat stages IIA, IIB, and III 4
• Lesions involving <30% of the femoral head have <5% progression to collapse 5

Late-Stage AVN (With Articular Collapse, Ficat Stage III-IV)

• Total hip arthroplasty is necessary for late-stage AVN with articular collapse 1
• For young adults with symptomatic hip AVN, especially with dysplasia or varus/valgus deformity, joint-preserving procedures such as osteotomy may be considered 2
• Cemented femoral fixation should be considered in elderly patients with poor bone quality to reduce periprosthetic fracture risk 2

Diagnostic Approach

MRI is the preferred diagnostic method for AVN, especially in patients with persistent joint pain but normal standard radiographs 1, 2

• Both sides should be imaged as AVN can be bilateral 2
• Initial radiography should exclude other causes such as fracture, primary arthritis, or tumor 1, 2

Important Clinical Considerations

There is no evidence-based consensus on how osteonecrosis needs to be managed in pediatric ALL patients 6

• Systematic early screening by serial MRI might reduce osteonecrosis-associated morbidity, though this is not realistic in routine daily practice (grade of quality: very low) 6

Untreated AVN inevitably leads to early degenerative joint disease 2

• AVN causes up to one-third of all total hip arthroplasties in patients under 60 years of age 2
• Late presentation is a major negative prognostic factor 2

Treatment Algorithm

1. Confirm diagnosis with MRI if radiographs are normal but clinical suspicion exists 1
2. Stage the disease using Ficat and Arlet classification 4, 7
3. For early-stage disease (I-II): Protected weight-bearing, bisphosphonates, or core decompression with bone grafting 1, 4
4. For late-stage disease (III-IV): Total hip arthroplasty or joint-preserving procedures in select young patients 1, 2

The absence of magnetic field therapy from all current guidelines and the presence of well-established surgical and medical treatments makes MAHT an unproven and non-recommended approach for AVN management.