Hip Replacement (Hip Osteoarthritis): Surgery, Lifespan, and Living with an Artificial Hip Joint

A hip replacement is performed when the natural joint is no longer functioning properly.

This is the case, for example, with advanced hip osteoarthritis. In this condition, the femoral head can no longer glide smoothly within the acetabulum.

This leads to pain during everyday movements, which is initially treated conservatively—that is, without surgery. Watch the video to see how joint wear results from cartilage damage:

However, if this pain can no longer be relieved by conventional therapies, the only solution is an artificial joint replacement—a hip replacement.

You can use the following questions to determine whether a hip replacement is a suitable treatment option for you.

If you can answer “yes” to 4 or 5 of these questions, you should talk to your orthopedic surgeon about joint replacement:

• Does every step on level ground cause pain?
• Does climbing stairs cause you pain?
• Can you walk for less than 30 minutes without pain?
• Do you experience pain at night?
• Do you have trouble sitting down and standing up?
• Do you need pain medication several times a day?
• Do you find yourself thinking about the affected joint very often, even during everyday activities?
• Can you only engage in leisure activities and go shopping if you take pain medication beforehand as planned?

Modern hip replacements are modeled after nature and replicate all the natural components of a real joint. These include the spherical femoral head on the elongated stem and the acetabulum.

Ideally, the body’s own stabilizing ligament structures (tendons), which help support the joint, are preserved during surgery.

In hip replacement surgery, two different types of prostheses are generally used:

• the total hip replacement (THR), a complete joint replacement
• the partial prosthesis, in which the natural acetabulum is preserved

Surgeons can anchor the stem in the femoral neck. An artificial acetabulum typically consists of a cup in which the artificial femoral head can glide. This interaction is also known as a gliding pair.

From the Science Museum London / Science and Society Picture Library - Stainless steel and ultra-high molecular weight polyethylene hip replacement Uploaded by Mrjohncummings, CC BY-SA 2.0, Link

For young patients, surface replacement in the form of the McMinn cap prosthesis (Fig. 1) is used in hip surgery.

This approach results in excellent restoration of joint function with only minimal bone loss, which facilitates subsequent revision surgeries (hip prosthesis replacement).

When using a standard cementless acetabular prosthesis, surgeons simply cover the femoral head. This results in a nearly anatomical reconstruction of the joints.

The original size of the femoral head is preserved, enabling excellent joint mobility.

The most commonly used prosthesis type in the hip joint area is a femoral stem prosthesis.

This artificial hip joint is a combination of:

• a metal acetabular cup
• a polyethylene (PE / plastic) bearing surface on the acetabular side
• metal or ceramic, and
• a femoral stem component with a standardized acceptance cone for a prosthetic head made of metal or ceramic

This artificial joint head can have diameters that vary from person to person.

Depending on the choice of hip prosthesis, there are various bearing pairings for the joint components.

The material of a prosthesis consists, for example, of:

• metal/metal
• Plastic (PE)/ceramic
• Plastic (PE)/metal
• Ceramic/ceramic
• Metal/ceramic

The choice of materials depends on the specific requirements in each case, such as:

• Age
• Allergies to certain metals
• Mechanical stress
• Body weight

In addition to the McMinn cap prosthesis and the femoral stem prosthesis (Fig. 3), the long-established short-stem prosthesis (Fig. 2) has seen increasing popularity in recent years, with rising implantation rates.

Cap prosthesis – Short-shaft prosthesis – Femoral stem prosthesis

Another difference among hip prostheses lies in the type of fixation.

In the past, doctors generally implanted artificial joints onto or into the bone using a special plastic mixture (colloquially known as “bone cement”).

Today, it is also possible to implant the hip prosthesis cementlessly (cementless fixation).

This has been made possible by a special surface treatment of the implants. Laser beams modify the surface of the titanium material to create a porous microstructure.

This allows the implant to anchor very firmly in the bone and integrate with the healthy bone. This makes loosening of the prosthesis less likely over time.

Cemented prostheses are more difficult to remove than cementless ones. Since the lifespan of a total hip replacement (THR) is 15 years, removability is an important criterion when selecting the type of fixation.

This is because if doctors need to replace the artificial joint, the revision surgery should be easily performable.

A combination of both fixation methods is also possible. This is referred to as a “hybrid joint.”

The implanting surgeon selects the appropriate fixation method based on:

• Joint condition
• age, and
• the patient’s bone quality

The following guidelines apply:

Young, active patients under the age of 60 should receive a cementless fixation whenever possible. The reason for this is that a revision surgery is likely to be necessary once the prosthesis has reached the end of its service life.

For patients up to age 75, a so-called hybrid prosthesis—that is, a cementless cup and a cemented stem—is preferred.

Elderly patients over 75 years of age usually benefit from a fully cemented option. Their bone is often no longer very strong, so they require additional cement stabilization.

The clinic team selects the best prosthesis design based on the specific details gathered during the preliminary consultation and those visible in the X-ray.

They base their decision on:

• The most biocompatible prosthesis material
• The prosthesis shape that fits best for the individual

The most important criterion for the type of prosthesis fixation is bone quality: cemented, cementless, or hybrid.

Fully cemented, cementless, and partially cemented hip prostheses

 

In most cases, the surgery to implant a hip prosthesis is an invasive procedure and must be performed under general anesthesia.

It is a major surgery in which doctors must remove the following structures:

• The natural joint, including the femoral head
• the femoral neck, if necessary

Doctors can then implant the artificial hip joint. For this reason, doctors require an open surgical field when implanting a hip prosthesis. This allows them to position and secure all structures correctly. The surgeon therefore needs an unobstructed view of the joint.

During the insertion of an artificial hip joint, the patient lies on their side, on the side opposite the one being operated on. Front and rear pelvic supports hold the pelvis in place. The leg being operated on rests in a leg support tray.

The hip replacement surgery procedure in detail:

1. For the surgery itself, surgeons make an incision in the affected hip
2. They then retract the muscles to the side so they can access the joint and the bones involved.
3. The surgeon now has a clear view of the affected joint. The actual hip replacement surgery begins. The surgeon prepares to implant the hip prosthesis. These surgical steps can be seen in the video:
4. Opening the joint and removing the inflamed synovial membrane
5. Removal of so-called bone spurs to restore the joint to its original shape and size.
6. Cutting and milling the damaged cartilage layers of the bony joint surfaces down to the healthy bone
7. Attaching the artificial joint components to the healthy, weight-bearing bone. The surgeon selects and adjusts these components based on the patient’s bone size.
8. Doctors securely anchor the implant and, if necessary, fix it in place with bone cement. They then use X-rays to verify that the hip prosthesis is correctly positioned within the leg. Since these components fit together precisely, like balls in a ball bearing, friction-free movement is possible after the surgery.
9. After doctors have anatomically correctly positioned the prosthesis, they suture the incision closed or clamp it off.

Terms such as “keyhole surgery,” arthroscopy, or minimally invasive surgery are increasingly common in the media.

The advantage of this method is minimal damage to the surrounding tissue.

To access the damaged joint, doctors must make an incision in the skin and surrounding tissue (such as muscles).

This tissue damage is often the reason why healing after surgery takes significantly longer.

With minimally invasive surgery, the incision can be significantly shorter than 10 cm, rather than the 20 cm that was typical in the past.

Depending on the patient’s anatomy (height, weight, required implant size), the length of the incision may vary. However, the surgeon should keep it as short as possible.

Minimally invasive hip arthroscopy: Hip arthroscopy © bilderzwerg / Fotolia

 

In fact, however, the purely cosmetic aspect of a shorter scar is not the reason for choosing a minimally invasive procedure.

Minimally invasive surgery primarily spares the muscles. Doctors choose access routes through natural, anatomically existing gaps in the tissue—for example, between individual muscles. Doctors no longer need to detach or cut through muscles; they simply gently push them apart along the direction of the muscle fibers.

In addition, they use special, miniaturized instruments that require less space in the operating room.

For the patient, this is a tissue-sparing procedure that results in less blood loss. As a result, blood transfusions are less frequently required. The hospital stay is shorter overall.

Because the muscles are preserved, patients are more mobile as early as the day after surgery. They are also able to perform and train important joint functions on their own.

Minimally invasive, therefore, means more than just a shorter incision. The key is preserving the tissue beneath the skin.

The implantation of an artificial hip joint is a permanent procedure. Doctors cannot reverse it. For total hip replacement (THR), they must remove the entire natural joint.

At least one orthopedic specialist and one expert in endoprosthetics must be involved before the surgery.

This is the only way to ensure that the artificial replacement is truly necessary and will lead to the best possible outcome for the patient.

As is customary, the patient undergoes several preoperative examinations. These ensure a safe and smooth procedure during implantation.

These preliminary examinations include:

• Blood draw to check blood values,
• an ECG to assess the cardiovascular system,
• a preoperative consultation with the anesthesiologist

What can the patient do before the artificial hip joint is implanted?

 

© RFBSIP / Fotolia

What can the patient do before the artificial hip joint is implanted?

The best preparation is a thorough discussion with the doctor and the hospital team. © RFBSIP / Fotolia

However, patients themselves can also play an active role in ensuring that the artificial joint replacement is a success.

Mental Preparation for the Artificial Hip Joint

Even if the pain significantly affects the patient, hip replacement surgery is not an emergency procedure but a carefully planned operation.

Nevertheless, despite all the advances in surgical techniques, new medications, and modern anesthesia methods, there is always a small risk.

On the other hand, the symptoms caused by the patient’s condition significantly limit their quality of life and enjoyment of life. Therefore, the pros and cons must be carefully weighed—your doctor will help you with this.

Diet Before Hip Replacement Surgery

A healthy diet should already play an important role in your daily life. However, it is even more important in the run-up to surgery. Sometimes patients—due to recent limitations in mobility—have “put on a few pounds.”

You should now consciously—but not forcefully—reduce this weight. Your primary care physician or internist can help you develop a gentle diet plan. You should not lose more than 1 kg per week.

The following rule of thumb is recommended to ensure you are in good physical condition for surgery and to promote proper wound healing.

In general, your diet should include all food groups:

• Carbohydrates in the form of whole-grain products
• Plenty of fruits and vegetables
• Lean meat
• Protein-enriched foods, and
• Calcium-rich dairy products

Exercise even before surgery

Due to the joint disease, the muscles surrounding the joint are weakened, shortened, and in some cases have already atrophied (muscle atrophy).

However, before surgery, the patient should begin training these muscles on their own. If they experience too much pain while doing so, they should avoid these movements and focus more on isometric exercises.

Daily exercises performed on their own will improve the healing process after surgery.

Medications Before the Scheduled Surgery

In addition to the joint disease, most patients have one or more comorbid conditions, such as:

• high blood pressure or
• diabetes

As a result, they often need to take medication regularly. However, some common medications (such as aspirin) can pose a risk in connection with surgery. They increase surgical risk, particularly when combined with anesthetics.

For this reason, when scheduling their artificial hip replacement, patients receive a list of medications to avoid.

The patient should consult with their primary care physician regarding this matter. If necessary, they should stop taking or switch medications well in advance of the procedure.

Postoperative care following a partial hip replacement or total hip replacement (THR) is complex and takes time. The artificial hip joint must gradually get used to and adapt to its new functions. Professional orthopedic rehabilitation is recommended.

Exercise is important after hip replacement surgery to maintain the prosthesis’s functionality and to rebuild muscle strength.

At the same time, stronger muscles protect all joints from overuse and thus also from signs of wear and tear.

After surgery and the implantation of a hip prosthesis, the best way to rebuild muscle strength is through physical therapy. The treatment plan should be tailored precisely to the patient and their needs.

How long does a hip replacement last?

The durability of a modern hip replacement is very good. Studies show that a hip replacement today lasts an average of 15 to 20 years, and often even longer. Its lifespan depends on the level of activity, the patient’s weight, and bone quality. If the prosthesis becomes loose, it can be replaced.

When can I walk again after surgery?

Thanks to modern surgical techniques, most patients are able to put their full weight on the leg immediately after surgery. Patients usually take their first steps on the day of surgery or the following day. Walking aids are generally used for 4 to 6 weeks as a safety measure.

Is it possible to play sports with an artificial hip?

Yes, exercise is actually important for the prosthesis’s longevity, as it strengthens the muscles and fortifies the bone. Sports that are gentle on the joints, such as Nordic walking, cycling, swimming, or golf, are recommended. Contact sports and ball sports are generally not advised.

What is the difference between cemented and cementless implants?

With a cementless prosthesis, the bone grows directly onto the rough surface of the implant. This requires good bone quality and is often chosen for younger patients. With a cemented prosthesis, bone cement provides the support, offering immediate stability and making it ideal for patients with osteoporosis.

When can I drive again?

You’re usually able to drive again once you no longer need walking aids and your reaction time isn’t impaired by pain medication. This is typically about 4 to 6 weeks after surgery. However, always check with your doctor on a case-by-case basis.

How long does rehabilitation take?

Follow-up treatment (rehab) usually lasts three weeks. It can be done as an inpatient at a rehab clinic or on an outpatient basis. The goal is to build muscle strength, train your gait, and improve mobility.

Will I still have pain after the surgery?

The pain from the surgical incision usually subsides significantly after a few days and can be effectively managed with medication. The typical osteoarthritis pain often disappears immediately after the procedure. A slight feeling of pressure or muscle soreness may occur during the first few weeks.

Is there an age limit for the surgery?

No, there is no strict age limit. The decisive factors are the patient’s biological condition and the severity of their symptoms. Even very elderly patients benefit enormously from the relief from pain and the regained mobility provided by a hip replacement.