What are the causes of Avascular Necrosis (AVN) of the hip?

From the Guidelines

Avascular necrosis (AVN) of the hip is primarily caused by trauma, corticosteroid therapy, alcohol use, and other medical conditions that disrupt blood supply to the femoral head, leading to bone death and potential collapse of the hip joint. The causes of AVN can be categorized into several key factors, including:

• Trauma: Fractures or dislocations that disrupt blood flow to the hip, as reported in the 2022 update of the ACR Appropriateness Criteria for Osteonecrosis 1
• Corticosteroid therapy: Long-term use of corticosteroids can affect fat metabolism and blood vessel function, increasing the risk of AVN, as noted in the study by Nawata et al 1
• Alcohol use: Excessive alcohol consumption can damage blood vessels and increase fat in the bloodstream, contributing to the development of AVN, as mentioned in the 2022 update of the ACR Appropriateness Criteria for Osteonecrosis 1
• Medical conditions: Certain conditions, such as HIV, lymphoma/leukemia, blood dyscrasias, and Gaucher disease, can increase the risk of AVN, as listed in the study by Nawata et al 1
• Radiation therapy: Damage to blood vessels in the treated area can also contribute to the development of AVN, as reported in the 2022 update of the ACR Appropriateness Criteria for Osteonecrosis 1 Early diagnosis and treatment are crucial to prevent further bone damage and reduce the risk of hip joint destruction. Treatment options range from medication and physical therapy for early stages to surgical interventions like core decompression or total hip replacement for advanced cases, as discussed in the 2022 update of the ACR Appropriateness Criteria for Osteonecrosis 1. To reduce the risk of AVN, it is essential to limit alcohol intake, avoid long-term steroid use when possible, and seek prompt medical attention for hip injuries or unexplained hip pain.

From the Research

Causes of Avascular Necrosis (AVN) of the Hip

The causes of AVN of the hip can be categorized into traumatic and non-traumatic factors.

• Traumatic factors include:
  • Fractures, such as femoral neck fractures 2
  • Dislocations, including posterior hip dislocation with or without acetabular fracture 3
  • Surgical procedures related to hip fractures or dislocations 2
• Non-traumatic factors include:
  • Corticosteroid treatment 4, 2
  • Hypercholesterolemia 4
  • Sickle cell disease 4
  • Alcohol abuse 4, 2
  • Coagulopathy 5
  • Congenital conditions 5

Risk Factors for AVN Development

Several risk factors contribute to the development of AVN, including:

• Delayed reduction of the hip after dislocation 3
• Type of fracture (displaced or undisplaced) and time between injury and surgery 2
• Presence of comorbidities, such as diabetes mellitus and hypertension 5