What Is It?
Whenever a bone breaks or cracks, the injury is called a fracture. The leg has three bones that can fracture — the femur (the thighbone) and the tibia and fibula in the lower leg. When a fracture involves the knobby end portions of bones that are part of the hip, knee and ankle joints, the fracture is more complicated. This article describes only fractures of the straight shafts of the three long leg bones.
The femur is very strong, so it takes a lot of force to fracture this bone in healthy people. The femur usually fractures during high-impact trauma, especially in automobile accidents, industrial accidents, falls from high places or gunshot wounds to the thigh. If a low-impact bump or fall causes a femur to fracture, this may be a sign that the femur has been weakened by an illness, such as osteoporosis or cancer.