What to Expect from Partial Hip Replacement (Hemiarthroplasty)

Your hip joint is often described as a “ball-in-socket” joint. The “ball” is the femoral head, which is the rounded end of the femur. The femur is the large bone in your thigh.

The hip’s “socket” is the acetabulum. The acetabulum surrounds the femoral head, allowing it to move as your leg changes positions. A hemiarthroplasty replaces the femoral head. If the socket also needs to be replaced, you will need a THR.

If you have a fractured hip, a hemiarthroplasty may be necessary to restore healthy hip function. If the femoral head is fractured, but the acetabulum is intact, you may be a good candidate for a hemiarthroplasty. Your doctor may recommend a THR, depending on:

• the health of your entire hip joint
• your overall health
• your expected life expectancy
• your physical activity level

Initially, your doctor may try to manage your hip arthritis with physical therapy, pain medications, and a reduction in activities that put less stress on the hip joint.

Most patients with hip arthritis are treated with a total hip replacement. Traditionally these days, only patients with hip fractures (femoral neck fractures) are treated with a hemiarthroplasty.

In very rare cases, a patient may be treated with a hemiarthroplasty if they have a risk for joint instability.

A hemiarthroplasty procedure results in less surgical time and less blood loss than a THR. There may be less of a chance of hip dislocation following a hemiarthroplasty compared to a THR, too.

If the acetabulum is relatively healthy with little arthritis, a hemiarthroplasty may be the best option, especially among older adults who aren’t especially active.

Younger, more active people may do better with a THR. With THR, you are more likely to have less pain, better long-term function, and greater walking ability than you would with hemiarthroplasty.

A hemiarthroplasty is typically done immediately after a fall or other injury that caused a hip fracture, so there’s usually little you can do to prepare. The procedure requires an in-hospital stay of at least a couple of days.

If possible, you will want to have someone with you at the hospital, and to help make arrangements for your stay and your return home or to a step-down unit.

You may be given a general anesthetic, meaning you’ll be asleep for the procedure. Or you may be given a regional spinal anesthetic, where you’re still awake but your legs are numb. Your doctor will talk to you about your options and their recommendations.

The operation starts with an incision around the thigh near the hip. Some surgeons make the incision on the side (posterior approach), while others make the incision in the front of the hip (anterior approach).

Once the surgeon can see the joint, the femoral head is removed from the acetabulum.

A network of ligaments, tendons, and muscles keep the ball and socket in place. The femoral head is also detached from the rest of the femur. The inside of the femur is hollowed out and a metal stem is placed snugly inside the femur. Some stems will be secured with bone cement to lower the risk of femur fracture.

A prosthetic or artificial femoral head, also metal, is placed securely on the stem. This may be attached to another head that is lined with polyethylene (plastic). This is called a bipolar prosthesis (a head within a head). The incision is then sewn up and bandaged.

You will be prescribed pain medications immediately after your operation. Be sure to use them only as prescribed. Soon after the surgery, you should also begin physical therapy. This will start while you’re still in the hospital and continue after you’re sent home or discharged to a step-down unit.

You may have at-home therapy or follow-up appointments at a physical therapy facility. The duration of your therapy will depend on several factors, including your age and overall fitness. You may require the use of a cane or walker to prevent future falls.

You may have to permanently avoid or reduce activities that require heavy lifting or lots of climbing. Your ability to run and play sports, such as tennis, may also be limited.

However, low-impact exercise should be part of your lifestyle for all-around health. Talk with your doctor about activities you should and shouldn’t pursue in the months and years ahead.

Like any operation, a hemiarthroplasty poses some potential risks. Among them are:

Infection

The chances of developing an infection following hemiarthroplasty are about one percent, but if it does occur, the complications are serious. Infections can spread to the rest of the hip, potentially requiring another operation.

Infections may appear within a few days of the surgery or years later. Taking antibiotics before dental work, or operations on your bladder or colon may be recommended to prevent a bacterial infection spreading to your hip.

Blood clot

Any operation on the hips or legs raises the risk of a blood clot forming in a leg vein (deep vein thrombosis). If the clot is large enough, it can block circulation in the leg. Usually, you will be placed on a blood thinner after a hemiarthroplasty to reduce the risk of a blood clot.

A clot may also travel to the lungs (pulmonary embolism) and cause serious heart and lung problems. Getting up and moving your legs as soon as possible after surgery is one of the most effective ways of preventing deep vein thrombosis.

Dislocation

If the ball slips out of the socket, it’s called a dislocation. It’s most common soon after a hemiarthroplasty, while the connective tissue in the joint is still healing. Your doctor and your physical therapist should explain how to avoid a hip dislocation.

Loosening

A successful hemiarthroplasty should last about 20 years without loosening. After that time or even earlier, the prosthetic hip may lose some of its connection to the bone. This is a painful complication and usually requires another surgery to fix it.

After 90 days, the mortality rate after hemiarthroplasty to treat a hip fracture is 20-35 percent. That is because the patient population with hip fractures is very sick and at risk.

Hip fracture patients require a lot of calories to recover. Make certain that you eat a high protein diet.

Brief episodes of pain or stiffness are common after a hemiarthroplasty. Prolonged discomfort in your replaced hip should not be expected or tolerated.

If the operation is successful and there are no complications, you should enjoy a long, healthy use of your new hip. It’s critical that you participate fully in physical therapy and go to all checkups after surgery. Make sure that you walk, with or without assistance, 3 times a day.