Avascular necrosis (AVN) is ischemic death of bone tissue caused by interruption of blood supply to the femoral head.
The condition leads to subchondral bone collapse, deformity of the femoral head and eventual secondary osteoarthritis of the hip joint.
Most commonly affects young and middle-aged adults, especially between 30–50 years.
Frequently bilateral, though severity may differ between hips.
Major risk factors include hip trauma, corticosteroid therapy, alcohol use, hemoglobinopathies, metabolic disorders, and systemic diseases.
Early stages may be asymptomatic or present with mild hip pain, while advanced stages produce severe pain, restricted movement, and gait disturbance.
MRI is the most sensitive investigation for early detection before radiographic changes appear.
