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 include increasing mobility, improving the function of the hip joint, and relieving pain.

Who Should Have Hip Replacement Surgery?

People with hip joint damage that causes pain and interferes with daily activities despite treatment may be candidates for hip replacement surgery. Osteoarthritis is the most common cause of this type of damage. However, other conditions, such as rheumatoid arthritis (a chronic inflammatory disease that causes joint pain, stiffness, and swelling), osteonecrosis (or avascular necrosis, which is the death 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.

In the past, doctors reserved hip replacement surgery primarily for people over 60 years of age. The thinking was that older people typically are less active and put less stress on the artificial hip than do younger people. In more 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 and last longer.

Today, a person’s overall health and activity level are more important than age in predicting a hip replacement’s success. Hip replacement may be problematic for people with some health problems, regardless of their age. For example, people who have chronic disorders such as Parkinson’s disease, or conditions that result in severe muscle weakness, are more likely than people without chronic diseases to damage or dislocate an artificial hip. People who are at high risk for infections or in poor health are less likely to recover successfully. Therefore they may not be good candidates for this surgery. Recent studies also suggest that people who elect to have surgery before advanced joint deterioration occurs tend to recover more easily and have better outcomes.

What Are Alternatives to Hip Replacement?

Before considering a total hip replacement, the doctor may try other methods of treatment, such as exercise, walking aids, and medication. An exercise program can strengthen the muscles around the hip joint. Walking aids such as canes and walkers may alleviate some of the stress from painful, damaged hips and help you to avoid or delay surgery.

For hip pain without inflammation, doctors usually recommend the analgesic medication acetminophen (Tylenol * ).

For hip pain with inflammation, treatment usually consists of nonsteroidal anti-inflammatory drugs, or NSAIDs. Some common NSAIDs are aspirin and ibuprofen (Motrin, Advil). If you need to take NSAIDs on a long-term basis or at doses that are higher than those obtainable over the counter, you should do so only under a doctor’s supervision. When neither NSAIDs nor analgesics are sufficient to relieve pain, doctors sometimes recommend combining the two. Again, this should be done only under a doctor’s supervision.

In some cases, a stronger analgesic medication such as tramadol or a product containing both acetaminophen and a narcotic analgesic such as codeine may be necessary to control pain.

* Brand names included in this booklet are provided as examples only, and their inclusion does not mean that these products are endorsed by the National Institutes of Health or any other Government agency. Also, if a particular brand name is not mentioned, this does not mean or imply that the product is unsatisfactory.

Topical analgesic products such as capsaicin and methylsalicylate may provide additional relief. Some people find that the nutritional supplement combination of glucosamine and chondroitin helps ease pain. People taking nutritional supplements, herbs, and other complementary and alternative medicines should inform their doctors to avoid harmful drug interactions.

In a small number of cases, doctors may prescribe corticosteroid medications, 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. The downside of corticosteroids is that they can cause further damage to the bones in the joint. Also, they carry the risk of side effects 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, which is essential for the body to function, you should not stop taking them suddenly, and you should follow the doctor’s instructions for discontinuing treatment.

Sometimes, corticosteroids are injected into the hip joint. A joint lubricant such as Hyaluronan may also be injected into the hip joint to relieve pain.

If exercise and medication do not relieve pain and improve joint function, the doctor may suggest a less complex corrective surgery before proceeding to hip replacement. One common alternative to hip replacement is an osteotomy. This procedure involves cutting and realigning bone, to shift the weight from a damaged and painful bone surface to a healthier one. Recovery from an osteotomy takes 6 to 12 months. Afterward, the function of the hip joint may continue to worsen and additional treatment may be needed. 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, or thigh bone, meets the pelvis, or hip bone. A ball at the end of the femur, called the femoral head, fits in a socket (the acetabulum) in the pelvis to allow a wide range of motion.

During a traditional hip replacement, which lasts from 1 to 2 hours, the surgeon makes a 6- to 8-inch incision over the side of the hip through the muscles and removes the diseased bone tissue and cartilage from the hip joint, while leaving the healthy parts of the joint intact. Then the surgeon replaces the head of the femur and acetabulum with new, artificial parts. The new hip is made of materials that allow a natural gliding motion of the joint.

In recent years, some surgeons have begun performing what is called a minimally invasive, or mini-incision, hip replacement, which requires smaller incisions and a shorter recovery time than traditional hip replacement. Candidates for this type of surgery are usually age 50 or younger, of normal weight based on body mass index, and healthier than candidates for traditional surgery. Joint resurfacing is also being used.

Regardless of whether you have traditional or minimally invasive surgery, the parts used to replace the joint are the same and come in two general varieties: cemented and uncemented.

Cemented parts are fastened to existing, healthy bone with a special glue or cement. Hip replacement using these parts is referred to as a “cemented” procedure. Uncemented parts rely on a process called biologic fixation, which holds them in place. This means that the parts are made with a porous surface that allows your own bone to grow into the pores and hold the new parts in place. Sometimes a doctor will use a cemented femur part and uncemented acetabular part. This combination is referred to as a hybrid replacement.

Is a Cemented or Uncemented Prosthesis Better?

The answer to this question is different for different people. Because each person’s condition is unique, the doctor and you must weigh the advantages and disadvantages.

Cemented replacements are more frequently used for older, less active people and people with weak bones, such as those who have osteoporosis, while uncemented replacements are more frequently used for younger, more active people.

Studies show that cemented and uncemented prostheses have comparable rates of success. Studies also indicate that if you need an additional hip replacement, or revision, the rates of success for cemented and uncemented prostheses are comparable. However, more long-term data are available in the United States for hip replacements with cemented prostheses, because doctors have been using them here since the late 1960s, whereas uncemented prostheses were not introduced until the late 1970s.

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, a person with uncemented replacements must limit activities for up to 3 months to protect the hip joint. Also, it is more common for someone with an uncemented prosthesis to experience thigh pain in the months following the surgery, while the bone is growing into the prosthesis.

What Can Be Expected Immediately After Surgery?

You will be allowed only limited movement immediately after hip replacement surgery. When you are in bed, pillows or a special device are usually used to brace the hip in the correct position. You 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 type of tube called a catheter may be used to drain urine until you are able to use the bathroom. The doctor will prescribe medicine for pain or discomfort.

On the day after surgery or sometimes on the day of surgery, therapists will teach you exercises to improve recovery. A respiratory therapist may ask you 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.

As early as 1 to 2 days after surgery, you may be able to sit on the edge of the bed, stand, and even walk with assistance.

While you are still in the hospital, a physical therapist may teach you exercises such as contracting and relaxing certain muscles, which can strengthen the hip. Because the new, artificial hip has a more limited range of movement than a natural, healthy hip, the physical therapist also will teach you the proper techniques for simple activities of daily living, such as bending and sitting, to prevent injury to your new hip.

How Long Are Recovery and Rehabilitation?

Usually, people do not spend more than 3 to 5 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, your overall health, and the success of your rehabilitation.

What Are Possible Complications of Hip Replacement Surgery?

According to the American Academy of Orthopaedic Surgeons, more than 193,000 total hip replacements are performed each year in the United States and more than 90 percent of these do not require revision.

New technology and advances in surgical techniques have greatly reduced the risks involved with hip replacements.

The most common problem that may arise 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). Studies are also looking at the use of bisphosphonates, ciprofloxacin, pentoxifylline, and other medications to prevent this bone resorption around the implants.

When Is Revision Surgery Necessary?

Hip replacement is one of the most successful orthopaedic surgeries performed. Studies have shown that more than 90 percent of people who have hip replacement surgery will never need to replace an artificial joint. However, because more people are having hip replacements at a younger age, and wearing away of the joint surface becomes a problem after 15 to 20 years, replacement of an artificial joint, which is also known as revision surgery, is becoming more common. It 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 for two reasons: if medication and lifestyle changes do not relieve pain and disability, or if x rays of the hip show damage to the bone around 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 Replacement?

Proper exercise can reduce 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 of these programs begin with safe range-of-motion activities and muscle-strengthening exercises. The doctor or therapist will decide when you 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 walking, stationary bicycling, swimming, and cross-country skiing. These exercises can increase muscle strength and cardiovascular fitness without injuring the new hip.

Source: National Institutes of Health