Which complication is specifically associated with hip fractures?

• A. Bleeding into the joint
• B. Osteomyelitis
• C. Avascular necrosis of the femoral head
• D. Deep vein thrombosis

Answer: (C)

When a hip fracture, especially a displaced femoral neck fracture, occurs, it can sever the small arteries that supply the femoral head. The femoral head relies on the retinacular arteries, predominantly the medial femoral circumflex artery, for its blood supply. If these vessels are damaged, the bone tissue in the head can lose perfusion and die, leading to avascular necrosis. This complication is the one most specifically linked to hip fractures because it directly results from disruption of the head’s blood supply, which is a unique risk path for this injury.

Bleeding into the joint can occur but is not a defining or unique consequence of hip fractures. Osteomyelitis is an infection of bone and is not an immediate or characteristic complication of a typical hip fracture unless infection risk factors or open fractures are present. Deep vein thrombosis is a common risk after any immobilizing injury, including hip fractures, but it is not specific to the fracture itself, whereas avascular necrosis arises from the fracture’s impact on the femoral head’s vascular supply.