Section 5. Bone, Joint, and Muscle Disorders

Chapter 62. Fractures

Topics: Introduction | Foot Fractures | Leg Fractures | Hip Fractures | Fractures of the Pelvis | Fractures of the Spinal Column | Shoulder Fractures | Arm Fractures | Hand Fractures

Hip Fractures

More than 270,000 hip fractures occur in the United States each year, with about 90% of them occurring in people older than 60. Hip fractures are more common in older people because of osteoporosis and because older people are more likely to fall. Use of some drugs increases the risk of hip fractures in older people (see Section 2, Chapter 14). One in three women and one in six men who reach age 90 will fracture a hip during his or her lifetime.

The upper end of the femur (thighbone) has large bony bumps (trochanters) where powerful muscles attach, then a short neck, and finally a spherical head that forms the outer half of the hip joint. Most hip fractures occur just below the spherical head (femoral neck or subcapital hip fractures) or through the trochanters (intertrochanteric hip fractures).

Femoral neck hip fractures are particularly problematic because the fracture often disrupts the blood supply to the femoral head, which forms the hip joint. Without a good blood supply, the bone cannot heal and eventually collapses and dies. Intertrochanteric hip fractures tend to create large broken bone surfaces that cause internal bleeding.

Symptoms and Diagnosis

Most older people fracture their hips by falling while walking on level ground, often when indoors. They usually cannot move their leg, much less stand or walk. When a doctor examines the person, the leg appears shortened and turned outward because of the unbalanced pull of muscles and gravity. Swelling and a purplish bruise develop because of blood leaking from the fracture.

An x-ray usually shows an obvious fracture and can help a doctor confirm the diagnosis. However, faint fracture lines may not be seen initially on x-ray. Thus, when a person continues to have pain and is unable to stand a day or more after a fall, the x-ray may have to be repeated or a magnetic resonance imaging (MRI) or bone scan obtained.

Treatment

Most people with a hip fracture are treated with surgery. The type of surgery depends on the type of fracture.

See the figure Repairing a Fractured Hip.

Treatment of severe femoral neck hip fractures involves removing the broken pieces surgically because the blood supply to the femoral head has been damaged. If damage to the femoral neck is incomplete (the break does not go all the way through), metal pins can be inserted surgically to support the femoral head (internal fixation). This is a smaller surgical procedure and the person's own hip joint is preserved.

Intertrochanteric hip fractures are treated with an implant, such as a sliding compression screw and side plate. This implant securely holds the bone fragments in their proper position while the fracture heals. The fixation is usually strong enough to permit the person to bear weight as tolerated. While the bone fragments generally heal in a couple of months, most people continue to improve in terms of comfort, strength, and walking ability for at least 6 months.

If partial hip replacement is needed, special metallic implants are used that have a polished spherical surface to match with the joint socket and a strong stem to fit within the central marrow canal of the thighbone. Some prosthetic implants are secured to the bone with a rapid-setting plastic cement. Others have special porous or ceramic coatings into which the surrounding living bone can grow and bond directly.

See the figure Replacing a Hip.

After joint replacement surgery, the person usually begins walking with crutches or a walker immediately and switches to a cane in 6 weeks. However, artificial joints do not last forever. The person, especially someone who is active or heavy, may need to undergo another operation 10 to 20 years later. Joint replacement is often advantageous for older people, because the likelihood that additional surgery will be needed is very low. In addition, older people benefit greatly from being able to walk almost immediately after surgery.

Sometimes the whole joint needs to be replaced. This procedure is performed rarely for fractures, but most commonly for osteoarthritis (see Section 5, Chapter 66).

If people with hip fractures are forced by their illness to stay in bed, they are at increased risk for serious complications, such as bedsores, blood clots leading to pulmonary embolism, mental confusion, and pneumonia. A great benefit of surgical fixation is that it allows the person to get out of bed and begin walking as soon as possible. Usually, the person can take a few steps with a walker 1 to 2 days after the operation. Physical rehabilitation is started as soon as possible (see Section 1, Chapter 7).