A simultaneous bilateral total hip replacement is the medical term for when both hip joints are replaced with artificial joints during a single surgery. The procedure is used for people with pain or loss of function in both hips caused by arthritis, childhood hip disorders, or other bone diseases that affect the hips.

For the vast majority of people who undergo the procedure, outcomes are excellent. After recovery and rehabilitation, they are able to fully participate independently in everyday activities without hip pain.

“At Yale, we have championed the direct anterior approach to hip surgery since 1975,” says Yale Medicine orthopaedic surgeon Michael Leslie, DO. “The surgeons at Yale are some of the most experienced in the world with respect to direct anterior approach. The procedure can often be done with live X-ray guidance or computer navigation, if appropriate, for a particular patient.”

Total hip replacement, also known as total hip arthroplasty, is a commonly performed surgical procedure in which a diseased or damaged hip joint is removed and replaced with metal, ceramic, or plastic parts that form a new hip joint. Around 450,000 total hip replacements occur each year in the United States.

Most people who undergo this type of surgery replace only one hip in what’s called a unilateral—or one-sided—total hip replacement. But when problems occur in both hips, bilateral total hip replacement—the surgical replacement of both hips—may be the best treatment option.

For many people, both hips can be replaced in one procedure called “simultaneous bilateral total hip replacement.” Sometimes called a “one-stage” or “single-stage” procedure, simultaneous bilateral total hip replacement occurs when both hips are replaced in a single surgery.

Because a simultaneous bilateral total hip replacement surgery involves only one procedure, it has the following advantages over a two-stage surgery:

• It requires a single exposure to anesthesia. (Use of anesthesia is safe, but it does come with a risk of side effects and complications.)
• It involves only one hospital stay.
• It is less expensive.
• It involves a single rehabilitation.

It’s important to note that having both hips replaced in a single surgical procedure rather than a two-stage surgery requires a longer procedure that is associated with greater blood loss, longer exposure to anesthesia, and increased risk for complications, such as blood clots. Because of this, simultaneous bilateral total hip replacement is typically reserved for younger patients in good overall health, as they are most likely to be able to tolerate the surgery.

Hip replacements are used to treat people who have tried other treatment options, such as physical therapy or even other surgical procedures, yet continue to experience loss of hip function with or without pain.

The following conditions can be treated with bilateral total hip replacement:

• Arthritis (osteoarthritis, rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis, among others)
• Osteonecrosis, also known as avascular necrosis (the death of bone tissue due to disruption of blood flow to part of a bone)
• Developmental dysplasia of the hip, when the ball and socket structure of the hip joint does not develop properly in babies or during childhood
• Other childhood hip disorders, including Legg-Calvé-Perthes disease
• Femoroacetabular impingement syndrome (FAI)

An orthopaedic surgeon will evaluate whether a patient is a good candidate for the surgery. In general, it is used to treat people 60 and younger who aren’t on daily medications for heart disease, high blood pressure, or other concerns. A surgeon will perform a thorough evaluation to determine whether a patient who has a condition that caused pain and loss of function in both hips is a good candidate for simultaneous bilateral hip replacement surgery.

The surgeon typically begins the evaluation by reviewing the patient’s medical history and performing a physical exam to check for cardiovascular disease, lung problems, or other diseases or disorders that could increase the risk of complications during or after the procedure. Bloodwork may also be necessary.

Patients approved for simultaneous bilateral total hip replacement surgery may need to prepare for the procedure. For example, those who are overweight or obese may be advised to lose weight, and those who smoke may be asked to stop smoking before the procedure.

The hip is what’s known as a “ball and socket” joint—the ball-shaped head of the thighbone fits into the bowl-shaped acetabulum, a bone in the pelvis. Cartilage normally covers the bones to protect them and allows them to glide smoothly over one another when the hip joint flexes.

The artificial hip is made up of several parts that mimic the components of the natural hip joint, including:

• Acetabular cup: Typically made of metal, this part replaces the acetabulum, the “socket” of the hip joint.
• Acetabular liner: A thin liner, most often made of plastic, that sits between the acetabular cup and femoral head, allowing them to glide smoothly over one another.
• Femoral stem: A metal stem attached to the thighbone that provides an “anchor” of stability to the artificial joint.
• Femoral head: Usually made of ceramic or metal, the ball-shaped head that replaces the natural head of the thighbone.

Before the procedure, you will be given anesthesia so you won’t feel pain during the surgery. You may be given general anesthesia, in which you will be unconscious for the surgery, or a spinal or epidural block that numbs your lower body. If a spinal or epidural is used, you may be given additional drugs to make you drowsy so you won’t remember the procedure.

The surgeon begins the procedure by making an incision in the skin over the back (posterior approach), side (lateral approach), or front (anterior approach) of the hip, depending on the surgical technique used.

The surgeon then cuts the neck of the thighbone, takes out the worn out femoral head, and removes cartilage from the acetabulum. Next, the surgeon removes diseased or damaged bone from the acetabulum. The man-made acetabular cup is then inserted and “press-fit” into place. Once the cup is in place, the surgeon then inserts the cup liner.

Next, the metal femoral stem is inserted into the thighbone. In some cases, it needs to be cemented in place. Finally, the artificial ball-shaped head is attached to the stem and inserted into the new acetabular cup.

The surgeon will check the length of the leg and flex the artificial hip joint to test the range of motion and stability. When the first hip procedure has been completed, the incision is closed, and the surgery is performed on the other hip.

After the procedure, people usually spend a few days recovering in the hospital. Patients will be given antibiotics, medications to help relieve pain, and drugs to prevent blood clots. Patients are encouraged to begin physical therapy as soon as possible after the procedure, often on the same day of surgery, and are expected to walk using a walker or crutches within 24 hours of the surgery.

Patients typically spend 2 to 3 days in the hospital. After discharge, patients will continue to follow a physical therapy program—which may be done at home—for several weeks to strengthen and improve the range of motion of their hips.

Like all surgeries, hip replacement surgery comes with a risk of certain complications. Some complications occur during or shortly after the surgery, while others may occur months or even years later.

Complications of simultaneous bilateral hip replacement may include the following:

• Infection
• Bleeding
• Complications from anesthesia
• Bone breakage
• Dislocation
• Limb-length discrepancy
• Wear and tear of the joint replacement

Certain factors have been associated with an increased risk of complications, including:

• Older age
• Obesity
• Frailty
• Smoking
• Hepatitis C

For most people, the outlook is very good, and the procedure typically has high patient satisfaction. After surgery, most people can return to their daily activities within three months, and most do so with little to no hip pain. In most cases, after hip replacement surgery, people should avoid participation in high-impact sports and activities, such as running, but they can participate in low-impact activities, such as swimming, biking, and walking.

Follow-up appointments with a member of the surgical team are important for monitoring recovery and long-term wear and tear on artificial joints.

“Yale Orthopaedics helped establish the direct anterior approach to total hip replacement over 45 years ago,” says Dr. Leslie. “We have taught countless trainees from across the globe how to safely provide patients this critical, innovative procedure. In the setting of bilateral total hip replacements, the direct anterior approach provides the best of all worlds—patients recover more quickly and are able to return to a full quality of life.”

“For patients with severe, debilitating, bilateral hip disease, a simultaneous bilateral total hip arthroplasty can be considered, as it may be difficult for patients to walk or recover if only one hip is treated surgically,” says Lee E. Rubin, MD, an orthopaedic surgeon at Yale Medicine. “The use of the direct anterior approach helps the surgeon to position the components correctly more often, which reduces the risks after surgery, and it preserves all the muscle around each hip, which facilitates an easier, less painful recovery, with less need for narcotics.”