What are the causes and treatment options for avascular necrosis of the head of

Clinical answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 13 May 2026Updated: 13 May 2026 Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

Causes of Avascular Necrosis (AVN) of the Femoral Head:

AVN of the femoral head is primarily caused by impaired blood supply to the bone, resulting in bone tissue death and subsequent structural collapse . Key risk factors include prolonged corticosteroid use, excessive alcohol consumption, trauma such as femoral neck fractures or hip dislocations that disrupt blood flow, systemic inflammatory diseases like lupus, and metabolic abnormalities such as hyperlipidemia . Additional nontraumatic causes include hematologic disorders, autoimmune diseases, and other systemic conditions . The femoral head is particularly vulnerable due to its terminal blood supply, making it the most common site for osteonecrosis .

Treatment Options:

The management of AVN depends largely on the stage of the disease, classified by systems such as the Ficat and Arlet or Association Research Circulation Osseous (ARCO) classifications, which distinguish precollapse stages (I–II) from postcollapse stages (III–IV) . Early diagnosis, often assisted by MRI imaging, is critical to optimize outcomes .

For early-stage AVN without femoral head collapse, conservative treatment may include lifestyle modifications such as reducing corticosteroid and alcohol use, physical therapy, and symptom management with NSAIDs or intra-articular injections, though these measures rarely prevent progression . Surgical intervention in early stages generally involves core decompression, which reduces intraosseous pressure and promotes revascularization by drilling into the necrotic bone . Core decompression is typically indicated in ARCO stages 1 and 2 and has demonstrated substantial improvements in patient outcomes and survival of the femoral head at two years, with success rates in the range of 70-80% . It may be augmented with biological or synthetic bone grafts, although conclusive evidence regarding superiority of augmentation is lacking .

In advanced stages characterized by femoral head collapse and joint degeneration (ARCO stages 3 and 4 or Ficat stage IV), joint-preserving procedures become less effective, and total hip arthroplasty (THA) is the treatment of choice . THA can be performed with cemented or cementless techniques, with cementless implants showing favorable long-term survivorship in AVN patients . The use of dual mobility cups and peripheral screw augmentation can enhance implant stability, especially in the context of poor bone quality .

Overall, early surgical intervention with core decompression is preferred to delay progression and preserve the native hip joint, while THA is reserved for cases with structural collapse and symptomatic joint degeneration .

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