Questions & Answers About Hip Replacement

From the National Institute of Arthritis and Musculoskeletal and Skin Diseases

What Is a Hip Replacement?

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 who suffer from severe muscle weakness
or Parkinson?s disease are more likely than healthy people 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 Alternatives to Total Hip Replacement?

Before considering a total hip replacement, the doctor may try other
methods of treatment, such as an exercise program and medication. An
exercise program can strengthen the muscles in the hip joint and
sometimes improve positioning of the hip and relieve pain. 

The doctor also may treat inflammation in the hip with non-steroidal
anti-inflammatory drugs, or NSAIDs. Some common NSAIDs are aspirin and
ibuprofen. Many of these medications are available without a
prescription, although a doctor also can prescribe NSAIDs in stronger

In a small number of cases, the doctor may prescribe corticosteroids,
such as prednisone or cortisone, if NSAIDs do not relieve pain.
Corticosteroids reduce joint inflammation and are frequently used to
treat rheumatic diseases such as rheumatoid arthritis. Corticosteroids
are not always a treatment option because they can cause further damage
to the bones in the joint. Some people experience side effects from
corticosteroids such as increased appetite, weight gain, and lower
resistance to infections. A doctor must prescribe and monitor
corticosteroid treatment. Because corticosteroids alter the body?s
natural hormone production, patients should not stop taking them
suddenly and should follow the doctor?s instructions for discontinuing

If physical therapy and medication do not relieve pain and improve joint
function, the doctor may suggest corrective surgery that is less complex
than a hip replacement, such as an osteotomy. Osteotomy is surgical
repositioning of the joint. The surgeon cuts away damaged bone and
tissue and restores the joint to its proper position. The goal of this
surgery is to restore the joint to its correct position, which helps to
distribute weight evenly in the joint. For some people, an osteotomy
relieves pain. Recovery from an osteotomy takes 6 to 12 months. After an
osteotomy, the function of the hip joint may continue to worsen and the
patient may need additional treatment. The length of time before another
surgery is needed varies greatly and depends on the condition of the
joint before the procedure.

What Does Hip Replacement Surgery Involve?

The hip joint is located where the upper end of the femur meets the
acetabulum. The femur, or thigh bone, looks like a long stem with a ball
on the end. The acetabulum is a socket or cup-like structure in the
pelvis, or hip bone. This ?ball and socket? arrangement allows a
wide range of motion, including sitting, standing, walking, and other
daily activities.

During hip replacement, the surgeon removes the diseased bone tissue and
cartilage from the hip joint. The healthy parts of the hip are left
intact. Then the surgeon replaces the head of the femur (the ball) and
the acetabulum (the socket) with new, artificial parts. The new hip is
made of materials that allow a natural, gliding motion of the joint. Hip
replacement surgery usually lasts 2 to 3 hours.

Sometimes the surgeon will use a special glue, or cement, to bond the
new parts of the hip joint to the existing, healthy bone. This is
referred to as a ?cemented? procedure. In an uncemented procedure,
the artificial parts are made of porous material that allows the
patient?s own bone to grow into the pores and hold the new parts in
place. Doctors sometimes use a ?hybrid? replacement, which consists
of a cemented femur part and an uncemented acetabular part.

Is a Cemented or Uncemented Prosthesis Better?

Cemented prostheses were developed 40 years ago. Uncemented prostheses
were developed about 20 years ago to try to avoid the possibility of
loosening parts and the breaking off of cement particles, which
sometimes happen in the cemented replacement. Because each person?s
condition is unique, the doctor and patient must weigh the advantages
and disadvantages to decide which type of prosthesis is better.

For some people, an uncemented prosthesis may last longer than cemented
replacements because there is no cement that can break away. And, if the
patient needs an additional hip replacement (which is likely in younger
people), also known as a revision, the surgery sometimes is easier if
the person has an uncemented prosthesis.

The primary disadvantage of an uncemented prosthesis is the extended
recovery period. Because it takes a long time for the natural bone to
grow and attach to the prosthesis, people with uncemented replacements
must limit activities for up to 3 months to protect the hip joint. The
process of natural bone growth also can cause thigh pain for several
months after the surgery.

Research has proven the effectiveness of cemented prostheses to reduce
pain and increase joint mobility. These results usually are noticeable
immediately after surgery. Cemented replacements are more frequently
used than cement less ones for older, less active people and people with
weak bones, such as those who have osteoporosis.

What Can Be Expected Immediately After Surgery?

Patients are allowed only limited movement immediately after hip
replacement surgery. When the patient is in bed, the hip usually is
braced with pillows or a special device that holds the hip in the
correct position. The patient may receive fluids through an intravenous
tube to replace fluids lost during surgery. There also may be a tube
located near the incision to drain fluid and a tube (catheter) may be
used to drain urine until the patient is able to use the bathroom. The
doctor will prescribe medicine for pain or discomfort.

How Long Are Recovery and Rehabilitation?

On the day after surgery or sometimes on the day of surgery, therapists
will teach the patient exercises that will improve recovery. A
respiratory therapist may ask the patient to breathe deeply, cough, or
blow into a simple device that measures lung capacity. These exercises
reduce the collection of fluid in the lungs after surgery.

A physical therapist may teach the patient exercises, such as
contracting and relaxing certain muscles, that can strengthen the hip.
Because the new, artificial hip has a more limited range of movement
than an un-diseased hip, the physical therapist also will teach the
patient proper techniques for simple activities of daily living, such as
bending and sitting, to prevent injury to the new hip. As early as 1 to
2 days after surgery, a patient may be able to sit on the edge of the
bed, stand, and even walk with assistance. 

Usually, people do not spend more than 10 days in the hospital after hip
replacement surgery. Full recovery from the surgery takes about 3 to 6
months, depending on the type of surgery, the overall health of the
patient, and the success of rehabilitation.

How to Prepare for Surgery and Recovery 

People can do many things before and after they have surgery to make
everyday tasks easier and help speed their recovery.

Before Surgery

Learn what to expect before, during, and after surgery. Request
information written for patients from the doctor or contact one of the
organizations listed near the end of this fact sheet. 
Arrange for someone to help you around the house for a week or two after
coming home from the hospital. 
Arrange for transportation to and from the hospital. 
Set up a ?recovery station? at home. Place the television remote
control, radio, telephone, medicine, tissues, waste basket, and pitcher
and glass next to the spot where you will spend the most time while you
Place items you use every day at arm level to avoid reaching up or
bending down. 
Stock up on kitchen staples and prepare food in advance, such as frozen
casseroles or soups that can be reheated and served easily. 

After Surgery

Follow the doctor?s instructions. 
Work with a physical therapist or other health care professional to
rehabilitate your hip. 
Wear an apron for carrying things around the house. This leaves hands
and arms free for balance or to use crutches. 
Use a long-handled ?reacher? to turn on lights or grab things that
are beyond arm?s length. Hospital personnel may provide one of these
or suggest where to buy one. 

What Are Possible Complications of Hip Replacement Surgery?

According the American Academy of Orthopedic Surgeons, approximately
120,000 hip replacement operations are performed each year in the United
States and less than 10 percent 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 orthopedic surgeries
performed?more than 90 percent 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

Doctors consider revision surgery for two reasons: 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.

What Types of Exercise Are Most Suitable for Someone With a Total Hip

Proper exercise can reduce joint pain and stiffness and increase
flexibility and muscle strength. People who have an artificial hip
should talk to their doctor or physical therapist about developing an
appropriate exercise program. Most exercise programs begin with safe
range-of-motion activities and muscle strengthening exercises. The
doctor or therapist will decide when the patient can move on to more
demanding activities. Many doctors recommend avoiding high-impact
activities, such as basketball, jogging, and tennis. These activities
can damage the new hip or cause loosening of its parts. Some recommended
exercises are cross-country skiing, swimming, walking, and stationary
bicycling. These exercises can increase muscle strength and
cardiovascular fitness without injuring the new hip.

What Hip Replacement Research Is Being Done?

To help avoid unsuccessful surgery, researchers are studying the types
of patients most likely to benefit from a hip replacement. Researchers
also are developing new surgical techniques, materials, and designs of
prostheses, and studying ways to reduce the inflammatory response of the
body to the prosthesis. Other areas of research address recovery and
rehabilitation programs, such as home health and outpatient programs.