What condition describes avascular necrosis of the femoral head often seen in corticosteroid use or sickle cell disease?

• A. Osteoarthritis of the hip
• B. Osteoporosis of the femoral neck
• C. Osteonecrosis (avascular necrosis) of the femoral head
• D. Trochanteric bursitis

Answer: (C)

Avascular necrosis of the femoral head occurs when the blood supply to the femoral head is disrupted, causing bone tissue to die and the head to collapse over time. This is classically linked to corticosteroid use and sickle cell disease, which both increase the risk of compromised blood flow to the bone. The scenario fits because those risk factors point to ischemia and subsequent necrosis rather than simple wear-and-tear or inflammatory bursitis.

In contrast, osteoarthritis of the hip is a degenerative process of cartilage that leads to joint space narrowing and osteophyte formation, typically in older adults. Osteoporosis of the femoral neck is a density disorder that raises fracture risk but does not describe bone death from loss of blood supply. Trochanteric bursitis involves inflammation of a bursa over the greater trochanter, causing lateral hip pain, not avascular necrosis of the femoral head.