The femur is the longest, thickest, and strongest bone in the human body. It extends from the pelvis to the top of the knee and typically measures about 20 inches (50 centimeters) in a person of average size. More accurately called the femur bone, this critical component of the human anatomy gives support to the entire upper body and ensures that energy is distributed downward to the foot. The bone is the location of most hip fractures, and is therefore typically one of the primary bones involved in hip replacement surgery.
One of several bones that enable the human body to contend with gravity, the femur plays an essential role in standing, walking, running, and jumping. Its shape, like a hollow cylinder, gives it the strength necessary to withstand a great deal of strain and bear heavy weight. The head of the bone is formed like a ball and fits into a deep socket in the pelvis called the acetabulum. Connecting the head to the thinner shaft section of bone is the femoral neck. Right below the neck, there is a bump on the outside called the greater trochanter. The large muscles of the buttocks attach to the femur at the bump.
Fractures of the femur typically occur in the neck of the bone. In young people, breaks usually happen as the result of a serious fall, blow, athletic injury, or vehicle accident. The cause in older people is can be those and can be accelerated by bone-weakening osteoporosis. Elderly people also sometimes experience femur fractures in an area slightly below the neck in what is called the intertrochanteric region. Breaks of the femur in either of these areas for both young and old are usually referred to as hip fractures and are normally considered to be serious injures. Healing of a fracture can take three to six months.
Risk factors for femoral fractures typically include engaging in high-contact sports like football or hockey, aging, onset of osteoporosis, decreased muscle mass, and suffering from diseases that often attack bones such as cancer. Several precautions can offer protection against femur fractures including avoiding the activities that involve high risk of major impact, keeping active to stay agile, working out to increase the muscle strength necessary to make falls less likely, eating foods that are high in calcium and vitamin D, wearing seat belts when driving or riding in a vehicle, and wearing the proper protective equipment and padding when participating in sports or engaging in other athletic activities.