Will the Knee Function Normally After a Total Knee Replacement?

When it becomes necessary to undergo knee replacement surgery, many patients wonder, will the knee function normally again? How different is an artificial knee compared to a natural one? This article aims to clarify these common concerns.
 

When is a total knee replacement necessary?

The majority of patients undergoing total knee replacement are elderly individuals with advanced osteoarthritis. Most have already tried other treatment options such as oral medication, physical therapy, or even intra-articular injections but continue to experience severe pain or worsening symptoms. At this stage, they often consult with a physician about undergoing surgery.
In almost all cases, patients themselves decide to proceed with the surgery because they want to resume a normal life without being burdened by the pain and limitations caused by osteoarthritis.

What does a knee implant look like? Is it similar to a real knee?

A knee implant mimics the shape of a natural knee and typically consists of 3 to 4 components. These parts are commonly made from cobalt-chromium and titanium alloys, while the center section uses a medical-grade plastic called polyethylene. Most implants across different brands follow similar standards and designs.

In the case of osteoarthritis in both knees, should the surgery be done one knee at a time or both knees at once?

Generally, the preferred approach is to operate on the knee that causes more pain first. In some cases, surgery on the second knee may not be necessary at all. This is because after the first knee is treated, it often becomes the dominant leg, improving function and reducing the load on the other side. As a result, pain in the second knee may decrease.

For patients who still require surgery on the second knee, doctors typically recommend waiting until all inflammation in the first knee has subsided before proceeding with the next surgery — usually with a gap of around 3 to 4 months.
If a patient wishes to undergo surgery on both knees at the same time, the advantages include completing the process in a single operation, experiencing pain only once, a shorter overall recovery period, and potentially lower overall costs. However, it’s important to understand that the risks are higher as surgery time is doubled and the chance of infection may increase.

Simultaneous bilateral knee replacement is best suited for patients with severe and deformed osteoarthritis in both knees. In such cases, operating on both knees at once can help the patient regain normal mobility more quickly. However, candidates for this procedure must be in good overall health with no serious medical conditions that could increase the risks associated with surgery.
 

Lifespan of a knee prosthesis

Doctors generally explain to patients that 90% of those who undergo knee replacement surgery can expect the implant to last more than 20 years; however, this depends on how well the patient uses and takes care of the new joint.

Postoperative mobility and wound care

Patients will begin walking training the day after surgery; most patients can walk and take care of themselves on that first day after their walking training. Since knee replacement is a major operation, some inflammation around the surgical site is normal after the procedure.

Physical therapy after knee replacement surgery

Physical therapy is conducted daily while the patient is still recovering in the hospital. This helps ensure that the patient can regain independence and return to their normal daily activities with confidence.
After being discharged from the hospital, as patients resume their regular routines and daily activities, their range of motion and muscle strength will gradually improve on their own naturally and progressively.

Are there any side effects after surgery?

Post-surgical swelling and mild fever are normal. However, signs of infection — such as excessive redness, pus, or abnormal swelling — require immediate medical attention.
One rare but serious condition to watch for is deep vein thrombosis (DVT), which causes severe leg swelling due to blood clots. It is more common in people of Caucasian descent but can also occur in people of Asian descent. Caution is especially needed during the first month after surgery.

Will the knee function just like before?

While an artificial knee isn't identical to a natural joint, it can significantly improve quality of life, especially for seniors. Many regain the ability to walk independently and participate in daily activities again — relieving both the patients and their families.

How long after surgery will it take for the knee to function normally?

Most patients regain near-normal knee function within 2 to 4 weeks post-surgery.

Can you perform daily activities such as climbing the stairs, squatting, or wearing high heels?
Everyday activities like walking, climbing the stairs, or sitting with your legs crossed can usually be done right after surgery. Sitting cross-legged on the floor or squatting is possible if the patient has strong muscles, as these positions may require the knee to bend more than 120 to 130 degrees. For elderly patients, achieving a bending angle of around 100 to 120 degrees is considered satisfactory.
As for wearing high heels, it is recommended to switch to lower heels, avoiding excessively high heels. From a scientific standpoint, high heels increase pressure on the knee joint more than flat shoes do.

Can you pass through airport security with a knee implant?

Yes. However, since the implant contains metal, it may trigger alarms at airport security. Bumrungrad International Hospital provides a medical card with patient details to confirm the presence of a metal implant.

Can you exercise, drive, or ride a motorcycle after surgery?

Patients are encouraged to do low-impact exercises such as swimming, water aerobics, and cycling. High-impact sports like running or tennis should be avoided as they can shorten the implant’s lifespan.
For upper-body workouts, there are no restrictions. For lower-body workouts, focus on strengthening the quadriceps muscles in the front of the thigh to improve walking and stair climbing.
Driving can usually resume 2 to 4 weeks after surgery, especially if the right knee was operated on. When it comes to riding a motorcycle — which requires more knee force — it’s recommended to wait 1 to 2 months, depending on recovery progress.

How to take care of yourself after knee replacement surgery

During the first 6 weeks after surgery, patients can return to their normal daily activities such as walking, climbing the stairs, and doing light housework. However, strenuous activities such as long-distance walking or intense exercise should be avoided.
After 2 to 3 months, once the wound is fully healed, inflammation has subsided, the swelling has decreased, the knee no longer feels warm, and the incision looks clean, patients can resume all normal activities. They can begin exercising and strengthening the muscles around the knee. It is recommended to avoid high-impact sports and activities that put excessive stress on the knee joint to prolong the lifespan of the knee prosthesis.

Are joint supplements necessary?

Since the cartilage is removed during knee replacement, joint supplements are no longer needed after surgery.

Advanced Arthritis & Arthroplasty Center specializes in treating hip and knee conditions. Our orthopedic surgeons have performed over a thousand joint replacement surgeries using high-quality implants and modern techniques.
We provide comprehensive pre- and post-operative care. Our mission is to help patients regain a high quality of life and return to the activities they love.

By 3A - Advanced Arthritis & Arthroplasty Center