Breaking Bones

Sixty-five-year-old Jane was helping her daughter prepare for a garage sale when she tripped over a cardboard box and fell, landing on her left hip. She cried out in pain and grabbed at the injured hip. After sitting for a few minutes, Jane asked her family to lift her into a chair.

After resting for 20 minutes, Jane was still in pain, but needed to use the bathroom. As she was helped into the house, she could bear a little weight on her left leg, but she suddenly heard a crack, her leg gave out, and she collapsed to the floor in agony. In that moment, her partial hip fracture became a complete hip fracture. For Jane, a simple fall at home turned into a severe injury, with a complex treatment program and uncertain recovery.

Introduction
According to the Centers for Disease Control and Prevention, more than one-third of adults over age 65 fall each year.1 Falls are the leading cause of injury-related deaths in elderly patients and the death rate from falls increased steadily from 1988-2000.2

In 2001, more than 1.6 million seniors were seen in emergency departments for fall injuries, resulting in 388,000 hospitalizations. Most of the fall-related hospitalizations were related to hip fractures. It is estimated that 98% of hip fractures are in the elderly.3

Hip fractures in children, adolescents and adults under age 65 are rare and are most likely a result of high-speed sports collisions, motor vehicle collisions or falls from a significant height. This article focuses on hip fractures in the elderly.

Hip Anatomy and Physiology
The hip is a ball and socket joint with a wide range of motion and is where the femur meets the pelvis. A hip fracture is actually a fracture of the proximal femur, including the head or neck of the femur, which angles inward towards the pelvis. The head of the femur is the ball that fits in the socket created by the acetabulum in the hip bone.3 The femur consists of the head, neck, greater trochanter (a palpable bony prominence that is even with the wrist of a supine patient's extended arm), lesser trochanter and intertrochanteric line, or ridge.

The acetabulum is composed of all three pelvic bones.5 Acetabulum fractures are primarily the result of high-energy trauma mechanisms, and not simple falls. In elderly patients, the proximal femur is more likely to fracture from a simple fall before the acetabulum fractures.

Several arteries branch off the femoral artery to bring oxygenated blood to the neck and head of the femur. This blood supply is often described as tenuous because fractures of the femoral neck can disrupt the blood supply to the femoral head.6

It is easy to see how a hip fracture could cause nerve impairment. The sciatic nerve--the major nerve of the body--innervates the muscles of the leg and foot, and also controls movement of the hip and knee.7

Motion of the hip joint is controlled by three major ligaments and several large muscles.6 The iliofemoral ligament attaches the ileum of the pelvis to the intertrochanteric line of the femur. The pubofemoral ligament attaches the pubis to the intertrochanteric line of the femur, and the ischiofemoral ligament attaches the ischium to the greater trochanter.8

A hip fracture is any break in the proximal end of the femur, from the head of the femur to the first 4 cm to 5 cm of the subtrochanteric area.6 After physical examination and x-ray study, hip fractures are classified, based on the location of the break, as either head, neck, intertrochanteric, trochanteric or subtrochanteric.6 Most hip fractures are displaced, meaning the head of the femur stays in the socket and the femur repositions to the anterior or posterior. Displacement leads to the injured extremity being shortened and externally rotated.

Fracture Classifications
Different fracture locations present with different physical exam findings.6

Femoral head fracture
A femoral head fracture is single or multiple fractures in the head of the femur. Femoral head fractures are commonly associated with hip dislocations.