What is the treatment for femoral neck necrosis?

Treatment for Femoral Neck Necrosis

The treatment for femoral neck necrosis should be based on the stage of disease, with early-stage disease managed by core decompression and advanced disease requiring arthroplasty. 1, 2

Staging and Risk Assessment

• Avascular necrosis (osteonecrosis) is characterized by bone death due to inadequate vascular supply, commonly affecting the femoral head 2
• The extent of necrosis is a critical prognostic factor:
  • Lesions involving <30% of femoral head have <5% progression to collapse 2, 3
  • Lesions involving >30% of femoral head have 46-83% risk of progression to collapse 2
• Risk factors include corticosteroid therapy, alcohol use, HIV, blood dyscrasias, chemotherapy, radiation therapy, patient age >40 years, and increased BMI (>24 kg/m²) 2
• The presence of joint effusion or bone marrow edema are additional risk factors for progression 2

Treatment Algorithm

Early-Stage Disease (Pre-Collapse)

• Noninvasive therapies with limited supporting evidence:
  • Pharmacological options: statins, bisphosphonates, anticoagulants 1, 2
  • Other modalities: extracorporeal shock wave therapy, hyperbaric oxygen 1, 2
• Core decompression for early-stage disease to prevent articular collapse 2, 4
  • Can be supplemented with injection of autologous bone marrow cells, vascular fibular grafting, or electric stimulation 1, 2
  • Protected weight-bearing is recommended following the procedure 4
  • Regular radiographic follow-up is essential to monitor for disease progression 4

Advanced Disease (Post-Collapse)

• For late-stage femoral head osteonecrosis with articular collapse:
  • Resurfacing hemiarthroplasty for less severe cases 1, 2
  • Total hip arthroplasty for cases with severe secondary osteoarthritis 1, 2
• The American College of Radiology recommends cemented femoral stems when performing arthroplasty 1
• In patients with unstable (displaced) femoral neck fractures, arthroplasty is recommended over fixation 1

Special Considerations

• Avascular necrosis is often bilateral in nontraumatic cases (70-80%), requiring evaluation of both hips 2
• Multifocal osteonecrosis can occur, potentially affecting the knee, ankle, and shoulder 2
• For young and active patients with non-complex cases, valgisation osteotomy according to Pauwels may lead to good results 5
• In patients under 50 years with combined pathology including avascular necrosis, salvage procedures with free fibular grafting can be a useful alternative to arthroplasty 5
• Early diagnosis is crucial to prevent articular collapse and the need for joint replacement 2

Imaging for Diagnosis and Treatment Planning

• MRI is the preferred imaging modality for early diagnosis after initial negative radiographs 1
• CT imaging is valuable for preoperative planning, showing the location and extent of articular collapse 3
• 3D-printed guide plates can improve surgical precision during core decompression 3, 4

Prevention in Fracture Cases

• Early reduction and internal fixation of femoral neck fractures may reduce the incidence and severity of avascular necrosis 6
• Type of fracture (displaced or undisplaced) and time between injury and surgery are critical factors in assessing the risk of developing AVN 7