What is the Difference Between a Total Knee Replacement and a Partial Knee Replacement: Knee Surgery Options

Total Knee Post Link Pic

Welcome to my informative guide on knee surgery options. As an orthopedic physical therapist, having seen hundreds, if not thousands, of knee surgeries using the total or particle knee replacement options, these are my conclusions.

When considering knee replacement surgery, understanding the difference between a total knee replacement (TKR) and a partial knee replacement (PKR) is crucial in making an informed decision. A TKR involves replacing the entire knee joint, while a PKR, also known as a unicompartmental knee replacement, targets only the damaged section of the knee.

In this article, I will share my opinions about the distinctions, advantages, and potential candidates for each procedure, helping you navigate your journey towards improved mobility and pain relief.

Understanding the Difference Between Total Knee Replacement and Partial Knee Replacement Surgery

When considering knee replacement surgery, it’s crucial to understand the differences between a total knee replacement and a partial knee replacement.

A total knee replacement, also known as total knee arthroplasty, involves replacing the entire knee joint with a prosthetic. The surgery is aimed at patients who experience significant knee pain due to advanced arthritis affecting multiple compartments of the knee. During total knee replacement surgery, the surgeon removes damaged cartilage and bone before fitting the new artificial components to restore the full function of the knee joint.

In contrast, a partial knee replacement, sometimes referred to as unicompartmental knee replacement, targets only the affected part of the knee, preserving as much of the natural knee structure as possible. This option is usually recommended for those with arthritis limited to just one area of the knee. During partial knee replacement surgery, only the damaged compartment is replaced, which can result in a quicker recovery and less pain post-surgery compared to a full knee replacement.

A research paper from the National Institute of Health determined that both TKR and PKR are effective, offer similar clinical outcomes, and result in a similar incidence of re-operations and complications. Based on their clinical findings, and results regarding the lower costs and better cost-effectiveness of PKR during the 5-year study period, they suggested that PKR should be considered the first choice for patients with late-stage isolated medial compartment osteoarthritis.

In my experience, my referring surgeons elect the partial knee replacement for the younger knee replacement candidate in anticipation of them needing another procedure, probably a total knee replacement, sometime during their remaining lifetime.

The difference between the two procedures lies in the extent of the surgery and the recovery. Total knee replacements are more common due to the widespread nature of knee arthritis, yet partial knee replacements can be advantageous if the damage is localized. Patients often experience pain relief and improved mobility with either type of knee replacement, but the choice largely depends on the individual’s condition and the surgeon’s recommendation.

Total Knee X ray
X-ray of a total knee replacement.

While total knee replacements may involve a longer recovery and rehabilitation period, they offer a more comprehensive solution for those with extensive knee damage. Knee replacement surgery, whether partial or total, can significantly improve the quality of life for individuals struggling with knee pain due to arthritis. The key is a proper assessment by a healthcare professional to determine the most suitable approach.

The ideal candidate for a total knee replacement is usually someone with chronic knee pain that hinders daily activities and rest, affecting all compartments of the knee. On the other hand, a partial knee replacement may be perfect for patients whose arthritis is confined to either the medial, lateral, or patellofemoral compartment of the knee. With partial knee replacement surgery, the untouched portions of the knee can continue to function normally, often allowing for a more natural feeling in the knee post-operation.

Both total and partial knee replacements have their place in the treatment of knee problems. Deciding on the best option involves a thorough evaluation by a skilled professional who considers factors like the extent of the arthritis, the patient’s age, activity level, and overall health. Regardless of the type of knee replacement surgery one undergoes, working with a physical therapist for targeted rehabilitation is paramount for regaining strength, flexibility, and function in the knee.

Ultimately, the goal of knee replacement, be it total or partial, is to alleviate pain and restore mobility. Through advancements in medical technology, today’s knee replacement surgeries have high success rates, significantly reducing knee pain caused by arthritis and other conditions. Patients deliberating between a total or partial knee replacement should discuss their concerns and expectations with an orthopedic surgeon to make an informed decision.

The Specifics of Partial Knee Replacement Versus Total Knee Surgery

When experiencing knee pain due to arthritis, it’s essential to understand the options available, particularly the difference between a total knee replacement and a partial knee replacement.

In a partial knee replacement, only the damaged area of the knee joint is removed and replaced, whereas in a total knee replacement, the entire knee joint is replaced. Partial knee replacements often result in a quicker recovery time because they are less invasive. In the knee joint, arthritis can affect one or multiple parts. If arthritis is contained to one area, you might be eligible for a partial knee replacement. However, if the arthritis is widespread within the knee joint, a total knee replacement might be suggested.

As a seasoned orthopedic physical therapist, my experience with particle knee replacement patients is that they experience more pain and have a harder time regaining range of motion (ROM) than my total knee replacement patients.
My opinion is that this is the result of age, not procedure.
My younger total knee recipients also have more pain and ROM difficulties than my patients over 65 years of age.

In considering the specifics of each procedure, it’s important to note that in a partial knee replacement, the surgeon targets either the medial (inside), lateral (outside), or patellofemoral (front) compartment of the knee. With a partial knee replacement, there is a focus on preserving as much of your knee’s natural structure and tissue as possible. This means that the unaffected parts of your knee joint are left in place.

My experience with partial replacement candidates is that they have a near-normal thickness of cartilage in the portion of the knee not being replaced.
The portion of the knee being replaced has accelerated deterioration, usually due to injury rather than degenerative deterioration.

In contrast, during a total knee replacement, the entire knee joint is resurfaced. This includes the lower end of the thigh bone (femur), the top of the shin bone (tibia), and often the back surface of the kneecap (patella).

Featured Image Pain after TKR croped
Total Knee Replacement Components,
the femur, and tibial components.

The decision between these knee surgery options typically hinges on the extent of knee arthritis and its impact on your daily life. Pain is a primary indicator, and in cases of severe pain, a total knee replacement may be necessary to provide significant relief and improve quality of life. The replacement materials used in total knee replacements and partial knee replacements are designed to mimic the motion of a natural knee. However, the surgical approach and extent of the procedure differ significantly, affecting both recovery trajectory and potential outcomes.

Recovery after knee replacement surgery is paramount, whether you undergo a partial or total knee replacement. Rehabilitation will focus on restoring knee strength, function, and range of motion.

Following a partial knee replacement, many patients notice a more ‘natural’ feel to the knee compared to those who receive a total knee replacement. This is often attributed to the less extensive surgery and preservation of original knee tissues in partial knee replacements. Patients typically return to an active lifestyle more quickly compared to those who have had a total knee procedure.

Moreover, the longevity of knee replacements is a common concern. The materials used in both partial and total knee replacements are durable, and designed to withstand the rigors of daily activities. Nevertheless, the survival of the knee replacement may vary based on several factors, including patient activity level, weight, and adherence to physician and physical therapist recommendations.

Ultimately, whether it’s with a partial knee replacement or a total knee replacement, the goal is to alleviate knee pain and improve function. Each option, partial knee versus total knee, has its place within orthopedic surgery, and a thorough evaluation is required to determine the best form of replacement for each individual case.

The replacement of only a part of the knee in partial knee replacements can be advantageous for the right candidate, just as the more comprehensive approach in a total knee replacement may be the better route for others. The distinction between these procedures is fundamental in laying the groundwork for your path to pain relief and recovery from knee arthritis.

Read my other articles about Total Knee Replacement

Total Knee Post Link Pic

Q: What is the difference between Total Knee Replacement (TKR) and Partial Knee Replacement (PKR)?
A: A Total Knee Replacement (TKR) involves replacing the entire knee joint with a prosthetic, while a Partial Knee Replacement (PKR), targets only the part of the knee that is damaged, preserving more of the knee’s natural anatomy. TKR is typically for advanced arthritis affecting multiple compartments, whereas PKR is for those with arthritis limited to one area of the knee.

Q: How does one determine whether to have a PKR or TKR?
A: The choice between PKR and TKR depends on the extent of your knee arthritis, your age, activity level, overall health, and the impact on your daily life. A healthcare professional will evaluate these factors. PKR may be suitable for patients whose arthritis is confined to one compartment, while TKR may be recommended for widespread arthritis.

Q: What are the advantages of PKR over TKR?
A: According to a research paper published in NIH, “Both TKR and PKR are effective, offer similar clinical outcomes, and result in a similar incidence of re-operations and complications. Based on our clinical findings, and results regarding the lower costs and better cost-effectiveness with PKR during the 5-year study period, we suggest that PKR should be considered the first choice for patients with late-stage isolated medial compartment osteoarthritis.”

Q: What does recovery involve after knee replacement surgery?
A: Recovery after knee replacement surgery involves rehabilitation to restore knee strength, function, and range of motion. This is critical in both PKR and TKR. Patients will work with a physical therapist for targeted rehabilitation aimed at regaining strength and flexibility. Recovery time varies, with PKR often having a shorter period before returning to normal activities.

Q: How long do knee replacement prosthetics last, and what happens when they wear out?
A: Knee replacement prosthetics are designed to be durable and withstand daily activities, but their longevity can depend on various factors including patient activity level and weight. When a knee replacement wears out, a revision surgery may be necessary. For PKR, this could mean a conversion to a TKR if complications arise or the prosthetic reaches the end of its lifespan.

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Dr. Donaldson is dually licensed; physical therapy in 1975 and doctor of chiropractic in 1995. He held credentials of Orthopedic Clinical Specialist in physical therapy for 20 years, QME in California, and taught at USC. He owns and operates an orthopedic physical therapy practice. See "About Me" page.

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