Hip Replacement

Last Updated: Nov. 1, 2003

Hip replacement, or arthroplasty, is a surgical procedure in which the diseased parts of the hip joint are removed and replaced with new, artificial parts. These artificial parts are called the prosthesis. The goals of hip replacement surgery are to improve mobility by relieving pain and improve function of the hip joint.

Who should have hip replacement surgery?
The most common reason that people have hip replacement surgery is the wearing down of the hip joint that results from osteoarthritis. Other conditions, such as rheumatoid arthritis (a chronic inflammatory disease that causes joint pain, stiffness, and swelling), avascular necrosis (loss of bone caused by insufficient blood supply), injury, and bone tumors also may lead to breakdown of the hip joint and the need for hip replacement surgery.

Before suggesting hip replacement surgery, the doctor is likely to try walking aids such as a cane, or non-surgical therapies such as medication and physical therapy. These therapies are not always effective in relieving pain and improving the function of the hip joint. Hip replacement may be an option if persistent pain and disability interfere with daily activities. Before a doctor recommends hip replacement, joint damage should be detectable on X-rays.

In the past, hip replacement surgery was an option primarily for people over 60 years of age. Typically, older people are less active and put less strain on the artificial hip than do younger, more active people. In recent years, however, doctors have found that hip replacement surgery can be very successful in younger people as well. New technology has improved the artificial parts, allowing them to withstand more stress and strain. A more important factor than age in determining the success of hip replacement is the overall health and activity level of the patient.

For some people who would otherwise qualify, hip replacement may be problematic. For example, people with chronic diseases such as those that result in severe muscle weakness or Parkinson’s disease are more likely than people without chronic diseases to damage or dislocate an artificial hip. Because people who are at high risk for infections or in poor health are less likely to recover successfully, doctors may not recommend hip replacement surgery for these patients.

What are possible complications of hip replacement surgery?
According to the American Academy of Orthopaedic Surgeons, approximately 120,000 hip replacement operations are performed each year in the United States and less than 10% require further surgery. New technology and advances in surgical techniques have greatly reduced the risks involved with hip replacements.

The most common problem that may happen soon after hip replacement surgery is hip dislocation. Because the artificial ball and socket are smaller than the normal ones, the ball can become dislodged from the socket if the hip is placed in certain positions. The most dangerous position usually is pulling the knees up to the chest.

The most common later complication of hip replacement surgery is an inflammatory reaction to tiny particles that gradually wear off of the artificial joint surfaces and are absorbed by the surrounding tissues. The inflammation may trigger the action of special cells that eat away some of the bone, causing the implant to loosen. To treat this complication, the doctor may use anti-inflammatory medications or recommend revision surgery (replacement of an artificial joint). Medical scientists are experimenting with new materials that last longer and cause less inflammation.

Less common complications of hip replacement surgery include infection, blood clots, and heterotopic bone formation (bone growth beyond the normal edges of bone).

When is revision surgery necessary?
Hip replacement is one of the most successful orthopaedic surgeries performed – more than 90% of people who have hip replacement surgery will never need revision surgery. However, because more younger people are having hip replacements, and wearing away of the joint surface becomes a problem after 15 to 20 years, revision surgery is becoming more common. Revision surgery is more difficult than first-time hip replacement surgery, and the outcome is generally not as good, so it is important to explore all available options before having additional surgery.

Doctors consider revision surgery if medication and lifestyle changes do not relieve pain and disability, or if X-rays of the hip show that damage has occurred to the artificial hip that must be corrected before it is too late for a successful revision. This surgery is usually considered only when bone loss, wearing of the joint surfaces, or joint loosening shows up on an X-ray. Other possible reasons for revision surgery include fracture, dislocation of the artificial parts, and infection.

Source: National Institute of Arthritis and Musculoskeletal and Skin Diseases

We Have Answers Do you have medical questions or need help finding a doctor? The experts at Columbia St. Mary's and Advanced Healthcare can help. Click here.