Osteonecrosis of the hip
Osteonecrosis of the hip Osteonecrosis of the hip (also called avascular necrosis [AVN] of the femoral head ) is a progressive, debilitating condition that results from interrupted blood supply to the femoral head , leading to bone ischemia, necrosis, and collapse of the articular surface. 1. Cause and Etiology Osteonecrosis can be traumatic or non-traumatic : A. Traumatic Osteonecrosis Cause : Disruption of blood supply due to: Femoral neck fractures Hip dislocations Iatrogenic injury (e.g., after hip surgery) Trauma disrupts retinacular arteries , branches of the medial femoral circumflex artery , leading to ischemia. B. Non-Traumatic Osteonecrosis Multifactorial , usually involving vascular compromise and cellular apoptosis . Major risk factors include: Corticosteroid use (the most common non-traumatic cause) Excessive alcohol intake Sickle cell disease Systemic lupus erythematosus Organ...