What is the pathophysiology of a hip fracture?

• A. A degenerative joint disease process
• B. A break in the proximal femur, often due to a fall, especially in older adults
• C. Inflammation of the synovial lining
• D. A dislocation of the hip

Answer: (B)

A hip fracture occurs when the proximal femur breaks, usually after a fall. In older adults, bones are often osteoporotic, so even low-energy events can cause a fracture. The break can be inside the joint capsule (femoral neck) or outside it (intertrochanteric region). In femoral neck fractures, there’s a real concern about blood supply to the femoral head being disrupted, which can lead to avascular necrosis and healing problems. In extracapsular fractures, bleeding and instability are common concerns, but the risk to the blood supply to the femoral head is different. This pattern fits a fracture of the proximal femur rather than degenerative joint disease, synovial inflammation, or a dislocation.