Avascular necrosis of the femoral head — also called osteonecrosis — is a condition in which the blood supply to the ball of the hip joint is disrupted, causing the bone tissue to die and, in advanced cases, to collapse. The result is progressive hip pain, stiffness, and loss of function. When the femoral head has collapsed significantly and the joint surface is damaged, hip replacement is often the most appropriate treatment.
In early stages, before significant collapse, non-surgical measures or procedures to preserve the femoral head may be considered. Once the joint surface is damaged, however, joint-preserving options become less effective and hip replacement is typically discussed. The timing of surgery depends on the stage of the condition, the degree of symptoms, and the patient's age and activity level. A clinical evaluation with imaging — including X-rays and in some cases an MRI — is necessary to stage the condition and guide treatment.
