Does avascular necrosis (AVN) of the femoral head differ in treatment from a nondisplaced fracture of the femoral head?

From the Guidelines

Avascular necrosis (AVN) of the femoral head and nondisplaced femoral head fractures have distinct treatment approaches due to their different pathophysiologies. Nondisplaced femoral head fractures typically require conservative management with protected weight-bearing for 6-12 weeks, pain control, and close monitoring with follow-up imaging to ensure proper healing, as seen in the management of hip fractures in older adults 1. In some cases, internal fixation with screws may be recommended if there's concern about displacement. For AVN, treatment depends on the stage of disease, with early-stage AVN potentially being managed with protected weight-bearing, medications like bisphosphonates, and possibly core decompression surgery to reduce intraosseous pressure and improve blood flow, as outlined in the ACR appropriateness criteria for osteonecrosis 1. Some key points to consider in the treatment of AVN include:

• The necrotic volume of epiphyseal osteonecrosis has been shown to be predictive of future articular collapse, with femoral heads with necrotic volume >30% progressing to collapse in 46% to 83% of cases 1.
• The increased risk for femoral head collapse has been associated with increased joint effusion, increased bone marrow edema about the focus of osteonecrosis, patient age >40 years, and increased body mass index (24 kg/m) 1.
• Advanced AVN typically requires more aggressive surgical intervention such as vascularized bone grafting, rotational osteotomy, or total hip arthroplasty, as these procedures can help restore circulation or replace the damaged joint, thereby improving patient outcomes in terms of morbidity, mortality, and quality of life. The different approaches reflect the distinct pathophysiology: fractures need time and stability to heal, while AVN involves progressive bone death due to compromised blood supply that won't improve without intervention to restore circulation or replace the damaged joint.

From the Research

Treatment of Avascular Necrosis (AVN) of the Femoral Head

• The treatment of AVN of the femoral head differs from that of a nondisplaced fracture of the femoral head, with a focus on preserving the femoral head and preventing further damage 2.
• Core decompression is a common treatment for early-stage AVN, with or without bone grafting, and has been shown to be effective in preventing further progression of the disease and improving outcomes 3, 4.
• Other treatment options for AVN include arthroscopic core decompression, biological stimulation for bone-guided regeneration, and autologous stem cell therapy, which have been shown to be effective in improving pain and function in patients with AVN 5, 6, 4.

Comparison to Nondisplaced Fracture Treatment

• In contrast to AVN, nondisplaced fractures of the femoral head are often treated conservatively, with a focus on immobilization and pain management, rather than surgical intervention 2.
• However, if the fracture is displaced or if there is significant damage to the femoral head, surgical treatment may be necessary, which may include reduction and internal fixation or arthroplasty 2.

Importance of Early Diagnosis and Treatment

• Early diagnosis and treatment of AVN are critical to preventing further progression of the disease and improving outcomes, with treatment outcomes generally better when initiated early 2, 3, 4.
• A range of imaging techniques, including X-ray, MRI, and technetium scans, can be used to diagnose and stage AVN, with the goal of identifying the disease at an early stage and initiating treatment promptly 2.