Partial versus Total Knee Replacement
July 18, 2023

Partial versus Total Knee Replacement

Texas Health Center for Diagnostics and Surgery

Discover the advancements in knee replacement surgery, providing effective remedies for chronic osteoarthritis and joint stiffness. Learn about the differences between partial and total knee replacement, as well as the advantages of each procedure.

Categories:   Joint replacement Knee Replacement

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Pain. Swelling. Stiffness. Knee pain can limit your ability to stay active and enjoy life.

Don’t let knee pain slow you down. For patients who’ve tried the first line of treatment — medication, physical therapy and steroid injections, with no relief — surgical treatment options may offer a path to a return to your active lifestyle.

Each year, some 600,000 people in the U.S. — most of them ages 55-75 — undergo knee replacement surgery — according to the Agency for Healthcare Research and Quality.  

A typical patient undergoing knee replacement surgery has chronic osteoarthritis of the knee joint that has not responded to more conservative treatments like medication, bracing, injections, and physical therapy.

If knee pain and joint stiffness are affecting your quality of life or getting in the way of normal daily activity, you may be a candidate for a partial knee replacement or total knee replacement. Here’s what you need to know about the pros and cons of each procedure.


New Technology

If you have a friend or family member who underwent knee replacement surgery 10 to 20 years ago, know that surgeons have made astounding advances in joint replacement surgery in recent years. The advances in surgical techniques and the materials used in joint replacement have not only aided in a quicker recovery time and shorter hospital stays, but also longer lasting joints.

“When we look at the research and see the positive effects of the pain relief made possible by this kind of surgery, it becomes clear that this is one of the most effective remedies in the history of medicine,” according to Dr. Donald Hohman, a joint replacement specialist on the medical staff at Texas Health Center for Diagnostics & Surgery. “We have patients up and moving around as soon as they are able to do so after surgery, sometimes within just a few hours.”


What is the difference between total knee replacement and partial?

The knee joint is divided into three areas: medial (inside of the knee), lateral (outside of the knee) and patella (kneecap/front of the knee).

Arthroplasty is the term physicians use for any surgical procedure to restore the function of a joint. That may include resurfacing the bones, or the placement of an artificial joint.

In a total knee replacement, the surgeon removes the entire joint and replaces it with an artificial joint. In a partial knee replacement, either the medial or lateral compartments of the knee joint are removed and replaced with artificial parts.

With a partial knee replacement (also sometimes called a “unicompartmental arthroplasty”)  the surgeon is able to preserve more of the patient’s natural bone, tissue and ligaments.


What causes the need for a knee replacement?

Most patients who ultimately choose knee replacement have experienced difficulty walking or climbing stairs, due to symptoms such as pain in the knee, swelling in the knee or stiffness in the knee.

Knee replacement surgery — partial or total — is normally only recommended when pain or joint stiffness persists for weeks or months, and only if more conservative treatments, such as physical therapy or steroid injections, haven't helped reduce the pain or improve mobility.

The most common reason for knee replacement surgery is osteoarthritis. Other conditions that cause knee damage may include rheumatoid arthritis, a knee injury or gout.


What is osteoarthritis?

Osteoarthritis in the knee occurs when the cartilage in the joint becomes damaged through natural wear and tear, leaving little or no cushioning between the bones. That causes the bones to rub against each other as the knee moves, causing pain. Patients may also notice grinding or clicking noises in the knee.


How common is knee pain as we get older?

Knee pain is not normal, but it’s not unusual as people get older.

Every time you take a step, your knees absorb shock — about 1½ times your body weight. Over the years, that adds up. It’s a little like the treads on a tire: after 40,000 to 50,000 miles, those treads can start to wear out. With regular wear-and-tear, the pads of cartilage in your knees can weaken. After the cartilage is worn away, the bones rub against each other, causing swelling, stiffness, and pain. People are more likely to experience knee pain if they are overweight, have a history of knee injuries or a family history of osteoarthritis.


What are the treatments for knee pain?

Mild knee injuries often improve with rest and anti-inflammatory medications. Wearing a brace can stabilize your knee while it recovers. Other measures might include applying heat or ice packs, modifying activities to avoid causing pain, practicing gentle stretches or exercises, taking over-the-counter pain relievers such as ibuprofen or acetaminophen or topical treatments such as muscle creams or rubs.

If arthritis is causing knee pain, your doctor may recommend medication and physical therapy to strengthen the muscles supporting the knee, which can help relieve discomfort.

More serious knee pain may require knee replacement surgery to provide relief.


Who is a candidate for partial knee replacement?

Modern surgical techniques have delivered excellent results in both younger and older patients — but partial knee replacement is not for everyone. To be a candidate for a partial knee replacement, the damage to your knee must be limited to one area. For patients with inflammatory arthritis, significant knee stiffness, or ligament damage, partial knee replacement may not be an option.


What are the advantages of a partial knee replacement over a total knee replacement?

A partial knee replacement is less invasive, which usually results in faster recovery and less time in the hospital. Some patients with partial replacements also have fewer post-surgical restrictions than those with total knee replacements.

However, only a small percentage of patients qualify for a partial knee replacement. Most patients have two or more areas that are damaged or diseased. For those patients, a total knee replacement is typically a better option.

For those patients with rheumatoid arthritis, an autoimmune disease in which the body’s immune system attacks the joints, total knee replacement is often the best option. However, recent improvements in rheumatoid arthritis medications have allowed some patients to be considered for partial knee replacement.

Your health history will help your surgeon suggest the best procedure for you.


What are the risks associated with knee replacement?

Like any type of surgery, knee replacement surgery carries some risks. Blood clots may occur, typically in the leg, but they can travel to the lungs. (Surgeons usually recommend blood-thinning medications to reduce this risk.) Nerve damage can occur in the area where the implant is placed. Infection at the incision site or in the deeper tissue is also possible.

While the implants used for knee replacements are durable, they can loosen or become worn over time, which may lead to the need for revision surgery.


How does recovery differ between the two types of knee replacement surgery?

For those patients who qualify, partial knee replacement offers some advantages over total knee replacement: quicker recovery, less pain after surgery, less blood loss and lower risk of infection and blood clots.

Some patients report that a partial knee replacement feels more natural than a total knee replacement, because the bone, cartilage, and ligaments in the healthy parts of the knee are preserved. Partial knee patients usually experience more flexibility, as well, and are often able to squat and kneel after surgery.

Patients who undergo total knee replacement surgery can expect a longer recovery period and more restrictions after the procedure. While activities like jumping from heights, running, and singles tennis aren’t recommended, people with a total knee replacement may golf, walk, bike, swim, play doubles tennis, and in some cases even ski at moderate levels.

The key disadvantage of partial knee replacement compared with total knee replacement is the potential need for more surgery. For example, a total knee replacement may be necessary in the future if arthritis develops in the parts of the knee that have not been replaced. The need for revision surgery (additional surgery) is slightly higher for patients who’ve undergone partial knee replacement rather than total knee replacement. With a partial knee replacement, the parts of the knee that were not replaced can deteriorate over time, which may lead to the need for revision surgery.


Robotic surgery

In many cases, robotic-assisted knee replacement surgery may be an option, offering the patient sophisticated treatments with less downtime. With robotic-assisted surgery, the surgeon selectively and precisely pinpoints the portion of the patient’s knee damaged by osteoarthritis, and then resurfaces the affected area of the knee while sparing the surrounding tissue. Many patients experience less pain during recovery. Other advantages include lower risk of infection, reduced blood loss and shorter hospital stays. With traditional techniques, the surgeon may need to make much larger incisions to complete that part of the procedure.



Is it better to have a partial or full knee replacement?

Compared to total knee replacement, partial knee replacement better preserves range of motion and knee function because it retains healthy tissue and bone in the knee. For these reasons, patients tend to be more satisfied with partial knee replacement compared with total knee replacement. However, partial knee replacement is not an option for many patients.

What are the disadvantages of a partial knee replacement?

Disadvantages of partial knee replacement include a slightly higher risk of earlier loosening and the need for revision surgery. This can be difficult to predict in any given patient, but many patients enjoy 15-20 years of excellent function with a partial implant.


The Takeaway

Surgeons on the medical staff at Texas Health Center for Diagnostics and Surgery perform hundreds of partial and total knee replacement surgeries each year. For more information, read this blog by surgeon Dr. Donald Hohman, Everything You Need to Know About Knee Replacement Surgery.  Learn more about knee replacement surgery at THCDS here.