Bipolar hemiarthroplasty (BHA) is a surgical treatment for femoral neck fractures of the hip. An artificial joint with two bearings replaces the damaged joint. The bearings allow the head to swivel during movement, preventing wear and tear on the hip joint.

Hip fractures are common in older adults, causing up to 300,000 hospitalizations annually in the United States. Hip fractures can negatively affect a person’s mobility, mental health, and overall independence. In some cases, they may lead to significant morbidity and even death.

Femoral neck fractures comprise nearly half of all hip fractures. BHA is the standard treatment for femoral neck fractures.

This article discusses BHA and what to expect from it. It also provides answers to common questions about the procedure.

An x-ray of a person's hips showing a bipolar hemiarthroplasty device in their hip joint.Share on Pinterest
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BHA involves replacing damaged hip joints with artificial joints.

Doctors recommend hip arthroplasty in people with displaced femoral neck fractures (DFNF), a type of hip fracture in the top of the thigh bone, called the femur. The fracture can tear the blood vessels and cut off the blood supply to the femoral head, which is the “ball” of the “ball-and-socket” hip joint.

In some cases, the surgery may involve replacing both the hip socket and the femoral head, which is known as a total hip replacement (THR). In other cases, surgeons will use hemiarthroplasty and replace just the femoral head.

There are two hemiarthroplasty implant categories: unipolar and bipolar. BHA provides a prosthesis with two joints, allowing most movements to occur at the inner bearing between the prosthetic head and the plastic liner of the bipolar head.

On the other hand, unipolar hemiarthroplasty has a one-piece design that allows movement between the hip, prosthesis, and hip socket.

Learn more about hip replacement.

Several treatments exist for hip fractures, with the most suitable option depending on a person’s age and activity level, the fracture’s location, and bone stability.

Healthcare professionals recommend BHA for individuals who have not met the criteria for THR, which include:

  • independently mobile outdoors
  • requiring one stick or less for support
  • cognitively able
  • healthy enough to undergo an operation safely

BHA is a surgical procedure that will take place under general anesthesia, which means that the person is sedated.

Surgery

BHA surgery typically involves the following steps:

  1. A surgeon will make an incision along the outer aspect of the thigh to gain access to the hip joint.
  2. The surgeon will expose the fractured site, remove the femoral head from the acetabulum — the “socket” of the “ball-and-socket” hip joint — and then detach it from the rest of the femur.
  3. They will then hollow out the inside of the femur, where they will place the metal stem of the prosthesis.
  4. Once the stem is in place, the surgeon will attach the artificial prosthetic head, which they will then attach to the plastic-lined bipolar head.
  5. They will check the joint’s stability and range of motion before closing the incision with sutures and covering it with bandages.
  6. The surgeon may place a vacuum drain in the hip area to remove excess fluids for 48 hours. They will also use pillows to position the thighs to prevent the leg from turning inward.

Aftercare

A hemiarthroplasty requires a person to stay in the hospital for a few days so that they can recover and receive physical therapy, which aims to restore movement and expected joint function. Many people begin physical therapy the next day or as soon as they feel comfortable after surgery.

The healthcare team may ask individuals to sit or stand with support for 1–3 days after the surgery and walk with support within 4–5 days of the procedure. Doctors may also give the person blood thinners to prevent deep vein thrombosis. People may take these from 12 hours before the surgery until 35 days after the operation.

Recovery

The person will need to follow certain precautions until the hip heals. These will vary depending on the healthcare team’s specific instructions, but they typically include:

  • avoiding bending and twisting the hips
  • preventing the operated leg from crossing the midline
  • keeping the feet facing forward
  • using pillows to prevent the legs from crossing when sleeping
  • avoiding sitting on low chairs and avoiding hip movements beyond 90 degrees when seated
  • using crutches, elevated toilet seats, and grabbers

People can usually resume their daily activities by about 6 weeks after the surgery.

As with all surgery, bipolar hemiarthroplasty poses some potential risks. These include:

  • Blood clots: These can form in the deep veins of the legs or pelvis after surgery. Doctors may give people blood thinners to try to prevent blood clots.
  • Infection: A person will need to take antibiotics before and after the surgery to prevent infection.
  • Dislocation: Although the risk of hip dislocation is lower after BHA surgery than it is after THR and unipolar hemiarthroplasty, dislocation still occurs in some cases.
  • Injury to nerves or vessels: Nerves or vessels can become injured or stretched during surgery, but this is rare.
  • Mortality: The mortality rate in the first year following hip fracture surgery is high, in the range of 15–36%. Possible predictive factors for postoperative mortality include older age, male sex, clinical comorbidities, and cognitive impairment.

THR and BHA are both hip surgeries that can treat DFNF. THR involves replacing the hip socket and the head of the femur, while BHA only replaces the damaged femoral head.

BHA is a less complicated procedure, hence the shorter operative time. It is also less expensive than THR.

A 2020 study comparing the two stated that THR might be preferable for active elderly adults due to the procedure being superior for hip function and quality of life. However, the authors note that THR has a longer operative time and a higher risk of dislocations.

A similar 2022 study also found that BHA had a lower dislocation rate than both unipolar hip arthroplasty and THR.

Recent research has also shown that BHA can reduce the incidence of cerebrovascular accidents and improve early weight-bearing among older adults.

Below, we answer some common questions about BHA.

How soon can you walk again after surgery?

A person may be able to walk with support several hours after the anesthesia has worn off. However, it may take about 6 weeks for them to resume their daily activities without restrictions.

How long does bipolar hemiarthroplasty last?

A successful BHA procedure can last for an average of 12.5 years.

Hip fractures are prevalent, especially among older adults. Bipolar hemiarthroplasty is one of the treatment options for femoral neck fractures in older adults.

Unlike THR, this procedure only replaces one part of the hip joint. However, the implant contains two moving parts that aim to diminish joint wear and tear. Surgery can help individuals regain function and mobility without the limitations that pain causes.

Ahead of hip surgery, a person can speak with a doctor to learn about the risks and benefits of different surgical procedures and what they can expect from their chosen procedure.