Find a Doctor

Total hip replacement

History

Total hip replacement surgery has evolved over the years into a reliable and effective way to relieve disabling pain and allow patients to resume their active lives. Many of the advances in total hip replacement surgery were pioneered by Sir John Charnley, a British orthopaedist, in the early 1960's.

Dr. Charnley’s great contributions to this procedure include creating the first low-friction total hip arthroplasty by replacing the arthritic hip joint with a metal ball and polyethylene plastic socket. He fixed the prosthesis to the bone with polymethylmethacralate cement, which acted as a grouting to bond the implant to the native bone. Today, many of his principles form the foundation of modern total hip replacement surgery. Many patients who have had their hip replaced using Dr. Charnley’s technique still have a functioning prosthesis after over 30 years. The surgeons of the Hip and Knee service utilize the surgical techniques of Sir John Charnley as the foundation of modern total hip replacement surgery, along with modern modifications designed to make the implants last longer. Today, approximately 150,000 total hip replacements are performed annually in the United States.

The prosthetic implant

The implant for a total hip replacement is composed of 3 parts: the stem, the ball, and the socket. The stem is made out of metal, usually cobalt-chrome or titanium, and is placed within the native thighbone. The ball is usually made out of polished metal or ceramic, and fits on top of the stem. The socket is usually a combination of a plastic liner and a cobalt-chrome or titanium backing. All together, the components weigh about 1 to 2 lbs. They are fixed to the bone either with bone-in growth surfaces or with cement.

There are alternative materials to metal and plastic, namely ceramic-on-ceramic, and metal-on-metal. Each of these material combinations has advantages and disadvantages; learn more about each of these bearing materials by reading our piece on implant bearing surface materials.

The Hip Joint

The hip joint is a ball and socket joint made up of the femur (ball) and the acetabulum (socket).

hip-joint-img

The ends of the bone are covered with a smooth, glistening layer called articular cartilage. The articular cartilage is what allows the bones to glide smoothly with less resistance than ice sliding on ice. The articular cartilage can be seen on x-ray as the space in between the ball and the socket.

hip-joint-img2

The geometry of the hip joint allows for a large range of motion, and the hip is by nature a very stable joint because of the large contact area between the femur and acetabulum. In addition, there is a special cartilage surrounding the hip joint called the labrum, which also contributes to stability.

Arthritis of the Hip

Arthritis of the hip is a condition in which there is loss of the articular cartilage of the femoral head and acetabulum. This can be seen on x-ray as a loss of the space between the two ends of bone.

Because of the loss of the gliding surfaces of the bone, people with arthritis may feel as though their hip is stiff and their motion is limited. Sometimes people actually feel a catching or clicking within the hip. Generally, loading the hip joint with activities such as walking long distances, standing for long periods of time, or climbing stairs makes arthritis pain worse. The pain is usually felt in the groin, but also may be felt on the side of the hip, the buttock, and occasionally into the knee.

Arthritis of the hip usually occurs in people as they enter their 60’s-70’s, but this is variable depending upon factors such as weight, activity level, and hip anatomy. Arthritis may be caused by a variety of factors, including simple wear and tear, inflammatory disorders such as lupus or rheumatoid arthritis, infections, and trauma. The end result of all these processes is a loss of the cartilage of the hip joint, leading to bone rubbing against bone.

Another cause of hip arthritis in younger patients is femoroacetabular impingement, in which abnormal anatomy leads to premature cartilage deterioration.

Overview of surgery

Surgery may be the best option to treat hip arthritis. The exact type of surgery depends upon your age, anatomy, and underlying condition. Some examples of surgical options to treat arthritis include an osteotomy, which consists of cutting the bone to realign the joint; total hip replacement, and hip resurfacing.

An osteotomy is a good alternative if the patient is young and the arthritis is limited to a small area of the hip joint. It allows the surgeon to rotate the arthritic bone away from the hip joint, placing weightbearing on relatively uninvolved portions of the ball and socket. The advantage of this type of surgery is that the patient’s own hip joint is retained and could potentially provide many years of pain relief without the disadvantages of a prosthetic hip. The disadvantages include a longer course of rehabilitation and the possibility that arthritis could develop in the newly aligned hip.

Hip implant

Steps of Surgery

Hip replacement surgery involves cutting away the arthritic bone and inserting a prosthetic joint. Both the arthritic ball and socket are replaced, usually with a metal ball and a plastic socket. The ball is placed upon a stem that is implanted within the femur (thigh bone), with or without cement. The socket is inserted within the native acetabulum after removing the arthritic surface.

Implant in hip

Decision to have surgery

People often wonder when and why they should have their hip replaced. This is an individualized question that depends upon a person’s activity level and functional needs. Many people with arthritis live with pain that prevents them from participating in activities that they love, or pain that interferes with their sleep; others are so debilitated that they have difficult putting on their shoes and socks. Total hip replacement offers a solution to the problem of arthritis and is performed with the goal of pain relief and resumption of activity. A consensus statement by the National Institutes of Health stated "total hip replacement (THR) is one of the most successful surgical procedures and provides immediate and substantial improvement in a patient’s pain, mobility, and quality of life. Compared to treatments for other chronic debilitating diseases, THR is highly cost effective"(1994).

A total hip replacement is considered a major operation, and the decision to undergo total hip replacement is not a trivial one. People usually decide to undergo surgery when they feel they can no longer live with the pain of their arthritis.

The prosthetic implant

The implant for a total hip replacement is composed of 3 parts: the stem, the ball, and the socket. The stem is made out of metal, usually cobalt-chrome or titanium, and is placed within the native thighbone. The ball is usually made out of polished metal or ceramic, and fits on top of the stem. The socket is usually a combination of a plastic liner and a cobalt-chrome or titanium backing. All together, the components weigh about 1 to 2 lbs. They are fixed to the bone either with bone-ingrowth surfaces or with cement.

There are alternative materials to metal and plastic, namely ceramic-on-ceramic, and metal-on-metal. Each of these material combinations has advantages and disadvantages; learn more about each of these bearing materials by reading our piece on implant bearing surface materials.

The procedure

The total hip replacement is performed in an operating room with a special laminar airflow system, which helps reduce the chance of infection. Your surgeon will be wearing a "spacesuit", also designed to reduce the chance of infection. The entire surgical team will consist of your surgeon, two to three assistants, and a scrub nurse.

The anesthesia for a total hip replacement is given through an epidural catheter, which is a small tube inserted into the back. This is the same type of anesthesia given to women in labor. You will be made numb from the waist down so that you will not feel anything. The catheter stays in for 1-2 days after the surgery to help with your post-operative pain control. During the course of the operation, you can be as awake or as sleepy as you want to be.

After the epidural block is administered, you will be placed on your side. The incision for a total hip replacement is made along the side of your hip. The incision will measure anywhere from 4 to 10 inches, depending upon your anatomy. It is well-covered by undergarments and is usually not visible when wearing clothes.

The arthritic ball and socket are exposed and removed with power instruments. The bone is prepared to receive the artificial hip joint, and then the prosthesis is inserted. During the closure, two drains may be inserted around the operated area to assist with the evacuation of blood. A combination of staples and/or sutures are used to close the skin.

Your pathway to recovery

The entire operation will take from 1 to 2 hours. Afterwards, you will be brought to the recovery room, where your blood work will be checked, and an x-ray of your new hip will be taken. Most patients can be brought to a regular room within a few hours; others will need to stay overnight in the recovery room, as determined by your surgeon and anesthesiologist. Patients generally stay in the hospital for 3 to 4 days following total hip replacement surgery. Younger, more fit patients may be able to leave within 48 hours of surgery if deemed safe by our doctors and therapists.