A hip hemiarthroplasty is a surgical procedure where half of the hip is replaced. This procedure is typically used to repair a broken or fractured hip but can also be used to treat a hip damaged by arthritis.
Hip hemiarthroplasty is a procedure used to treat hip fractures that is like a total hip replacement but only part of the hip is replaced. Hemi means “half” and arthroplasty refers to “joint replacement.” Replacing the entire hip joint is called total hip replacement (THR). While this procedure is used to treat hip fractures, it is also used to treat hip arthritis. The recovery process is very similar to that of a total hip replacement. Physical therapy to regain both strength and flexibility in the hip is necessary. If the operation is successful and there are no complications, the patient should enjoy a long, healthy use of the new hip.
There are many benefits of getting a hip hemiarthroplasty as opposed to a more intensive procedure, such as a total hip replacement. For example, this procedure results in less surgical time and less blood loss, as well as a decreased chance of dislocating the hip after the procedure.
The main reason why an orthopaedic surgeon would choose to perform this procedure as opposed to a total hip replacement is if the acetabulum (where the head of the femur meets with the pelvis) is relatively healthy with little arthritis.
Indications
The 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 the thigh. The hip’s “socket” is the acetabulum. The acetabulum surrounds the femoral head, allowing it to move as the leg changes positions. A hemiarthroplasty replaces the femoral head. If the socket also needs to be replaced, a THR would be needed.
In a fractured hip or serious hip arthritis, a hemiarthroplasty may be necessary to restore healthy hip function. If the femoral head is fractured, but the acetabulum is intact, the patient may be a good candidate for a hemiarthroplasty. A doctor may recommend a THR, depending on:
- the health of the entire hip joint
- personal overall health
- expected life expectancy
- physical activity level
Initially, an orthopaedic doctor may try to manage hip arthritis with physical therapy, pain medications, and a reduction in activities that put less stress on the hip joint.
Diagnosis
When the hip is fractured or there is serious hip arthritis, a complete hip replacement may be necessary to restore function to the hip. If the femoral head is broken, but the acetabulum is intact, the patient may be a good candidate for a hemiarthroplasty.
Hemiarthroplasty vs. Total hip replacement
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 hermiarthroplasty.
Surgical Procedure
A hemiarthroplasty is typically done immediately after a fall or other injury that caused a hip fracture, so there’s usually little to do to prepare. The procedure requires an in-hospital stay of at least a couple of days. If possible, the patient needs to have someone at the hospital, arrangements for stay and return home or to a step-down unit should be made with the hospital.
The patient may be given a general anesthetic, meaning will be asleep for the procedure. Or given a regional anesthetic, like an epidural, where the patient is still awake but the legs are numb. The anaesthesia provider will talk to the patient about available options and their recommendations.
The operation starts with an incision on the side of the thigh near the hip. 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.
During a hip hemiarthroplasty, the head of the damaged thighbone (femur) is replaced with an implant that stabilizes the femur while restoring function to the hip. When the head of the femur is removed, the inside of the femur is hollowed out, and a metal stem is placed snugly inside the femur. Unlike a total hip replacement, only the ball or head of the femur is replaced. In a total hip replacement, both the ball of the femur and the entire hip socket are replaced.
Complications
There are some complications associated with this procedure. These include:
- Infection.
- Blot Clot.
- Dislocation.
- Loosening. When the prosthetic hip loses some of its connection to the bone prematurely.
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 the bladder or colon may be recommended to prevent a bacterial infection spreading to the 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.
A clot may also travel to the lungs (pulmonary embolism) and cause serious heart and lung problems. Getting up and moving the 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. The surgeon and the physical therapist should explain how to avoid a hip dislocation.
Loosening
A successful hemiarthroplasty should last about 12 to 15 years or more. 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.
Recovery
Immediately after the procedure, pain medications are prescribed. The patient begins physical therapy to help regain strength and flexibility in the hip. Physical therapy starts while still in the hospital and continues after the patient is sent home or discharged to a step-down facility.
After discharge from the hospital, at-home therapy or follow-up appointments at a physical therapy facility are necessary. The duration of therapy depends on several factors, including age and fitness.
As for the future, advice is given to permanently avoid or reduce activities that need heavy lifting or lots of climbing. Ability to run and play sports, such as tennis, may also be limited. But low-impact exercise should be part of the patient’s lifestyle for all-around health.