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 prostheses. The goals of hip replacement surgery include increasing mobility, improving the function of the hip joint, and relieving pain.
For the majority of people who have hip replacement surgery, the procedure results in:
- A decrease in pain
- Increased mobility
- Improvements in activities of daily living (ADLs)
- Improved quality of life
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 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.
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.
- Learn what to expect. Request information written for patients from the doctor.
- 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, wastebasket, and pitcher and glass next to the spot where you will spend the most time while you recover.
- Place items you use each day at arm level to avoid reaching up or bending down.
- Stock up on kitchen supplies and prepare food in advance, such as frozen casseroles or soups that can be reheated and served easily.
- 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.
- Explore medical equipment and supplies to assist in daily activities. For example, 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.
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.