How Many Types of Knee Replacements Are There and How to Choose the Right Option for Knee Osteoarthritis

Knee osteoarthritis occurs when cartilage wears down and bones become deformed, preventing the joint from distributing weight effectively. Patients commonly experience knee pain and difficulty with movement.
Knee replacement surgery is an effective treatment option for knee osteoarthritis, designed to reduce pain and help patients return to their daily activities as close to normal as possible.
Knee replacements are made from high-quality metal alloy and polyethylene bearing surfaces. Choosing between mobile or fixed-bearing designs depends on the type of knee surgery.

There are two main types of knee replacements: TKA (Total Knee Arthroplasty) or total knee replacement surgery, which is suitable for patients with severe knee osteoarthritis or those who don’t respond to other treatments, and UKA (Unicompartmental Knee Arthroplasty) or partial knee replacement surgery, which is ideal for patients whose knees aren’t completely damaged. UKA offers advantages including faster recovery, smaller surgical incisions, and more natural movement.
Regarding post-surgical recovery, TKA requires longer recovery time, with patients experiencing pain and stiffness for approximately 3-6 months and getting back to full function within 1-2 years. Meanwhile, UKA recovers faster, with patients returning to good function in approximately 6 weeks.
In terms of knee replacement lifespan, TKA can last approximately 15-20 years, while UKA has a longer lifespan of approximately 50 years (depending on usage and care).
At kdms Hospital in Bangkok, Thailand, we have a team of experienced surgeons with expertise in bone, joint, and muscle conditions who are skilled in performing both TKA and UKA, providing comprehensive follow-up care until patients can return to their normal lifestyle.

“How many types of knee replacements are there?” is a frequently asked question as knee replacement surgery is indeed an important treatment option for patients with knee osteoarthritis. The primary objective of this treatment is to reduce knee pain in patients and help them return to normal daily activities as much as possible. Doctors will consider knee replacement surgery after conservative treatments, including weight reduction, exercises to strengthen thigh muscles, and pain medications, fail to provide satisfactory results. That’s because the outcomes of conservative, or non-surgical, treatments also depend on each patient’s lifestyle and self-care practices.

This article will guide you through the different types of knee replacements, what TKA and UKA surgeries entail, who they’re suitable for, and how to choose the most appropriate option.

Table of Contents

What Are the Symptoms of Knee Osteoarthritis?

Knee osteoarthritis develops when bones become deformed or cartilage wears down and gets destroyed, resulting in impaired knee joint mechanics that cannot distribute weight-bearing forces effectively. Therefore, some parts of the knee bone must bear more weight than normal limits, leading to knee osteoarthritis symptoms. Patients experience knee pain and hear clicking sounds in the knee when standing or sitting. This condition commonly affects patients aged 40 and above. Initial treatment can be achieved through weight reduction, exercises to strengthen thigh muscles, and pain medications. However, if symptoms don’t improve, doctors will recommend surgical treatment for knee osteoarthritis and knee replacement.

What Are Knee Replacements Made Of?

Knee replacement devices are manufactured from the same materials: metal alloy and polyethylene bearing surfaces that separate the metal components. With different designs following surgical needs, knee replacements include:

Knee replacements for total knee replacement surgery (TKA) use fixed-bearing surfaces that don’t move.
Knee replacements for partial knee replacement surgery (UKA) include both mobile-bearing surfaces that can move and fixed-bearing surfaces that don’t move.

Types of Knee Replacements

For patients with knee osteoarthritis, there are 2 types of knee replacement surgery. Choosing a method depends on various patient indications and the surgeon’s clinical judgment:

Total Knee Replacement Surgery (Total Knee Arthroplasty: TKA)

Total knee replacement surgery (total knee arthroplasty: TKA) is a surgical procedure to remove all worn joint surfaces or deteriorated knee joints, including the inner, outer, and kneecap areas, then replace them with a knee replacement.

Benefits of total knee replacement surgery (total knee arthroplasty: TKA)

Total knee replacement surgery (total knee arthroplasty: TKA) is a standard knee replacement procedure. Doctors often choose total knee replacement surgery because it helps reduce the chance of surgical errors.

Who is suitable for total knee replacement surgery (total knee arthroplasty: TKA)?

Patients with knee osteoarthritis who cannot perform normal daily activities
Patients who have tried conservative treatments but there’s no improvement
Patients with knee osteoarthritis ranging from complete cartilage wear to bone-on-bone contact

Recovery after total knee replacement surgery (total knee arthroplasty: TKA)

Recovery after total knee replacement surgery (total knee arthroplasty: TKA) involves inflammatory processes remaining in the body for approximately 2 years. Patients will experience pain and stiffness for approximately 3-6 months after surgery due to the large amount of metal inserted into the body. The unnatural joint movement causes muscle pain and slow recovery after surgery, then gradually improves over time.

Lifespan of knee replacements for total knee replacement surgery (total knee arthroplasty: TKA)

Knee replacements for total knee replacement surgery (total knee arthroplasty: TKA) use fixed-bearing surfaces that don’t move. The artificial bearing surfaces will wear according to the patient’s lifestyle. Generally, there’s a possibility of revision surgery if the bearing surface wears out in another 15-20 years.

Partial Knee Replacement Surgery (Unicompartmental Knee Arthroplasty: UKA)

For patients whose knees aren’t completely damaged, doctors recommend partial knee replacement surgery (unicompartmental knee arthroplasty: UKA). It is a surgical procedure to remove only the deteriorated part of the knee and replace it with a knee replacement. This can be done for inner knee replacement, outer knee replacement, and kneecap compartments.

Benefits of partial knee replacement surgery (unicompartmental knee arthroplasty: UKA)

Surgery that preserves the healthy parts of the knee as they originally were
Small surgical incisions
After surgery, knee movement mechanisms will become natural and function well post-operatively
Reduces post-surgical side effects such as infection risk, bone fractures, and blood clots in legs, heart, and brain
Requires fewer post-operative medications, reducing side effects from pain medications

Who is suitable for partial knee replacement surgery (unicompartmental knee arthroplasty: UKA)?

Partial knee replacement surgery (unicompartmental knee arthroplasty: UKA) is suitable for knee osteoarthritis patients whose knees aren’t completely damaged. Regardless of patient age, this surgical method can be used to treat knee osteoarthritis symptoms in every person.

Recovery after partial knee replacement surgery (unicompartmental knee arthroplasty: UKA)

Since partial knee replacement surgery (unicompartmental knee arthroplasty: UKA) involves inserting less metal into the body and has designs that help joint movement mechanisms remain almost normal, muscles recover faster. Patients will move better and recover well within approximately 6 weeks.

Lifespan of knee replacements for partial knee replacement surgery (unicompartmental knee arthroplasty: UKA)

The design of knee replacements for partial knee replacement surgery (unicompartmental knee arthroplasty: UKA) use mobile-bearing surfaces that help reduce wear effectively, with a lifespan of approximately 50 years.

Important Information Before Knee Replacement Surgery

Most patients with chronic conditions such as high blood pressure and diabetes may also have knee osteoarthritis, which don’t pose problems for surgery.

However, patients with vascular problems such as heart disease or cerebrovascular disease are recommended to consult with internal medicine physicians to assess risk factors first. Typically, if risk factors are low to moderate, surgery can proceed immediately. Especially partial knee replacement surgery (unicompartmental knee arthroplasty: UKA), this surgery involves less trauma, reduces side effects, and is much safer for patients.

The Perks of Having Knee Replacement Surgery at kdms Hospital

Knee replacement surgery at kdms Hospital in Bangkok, Thailand, allows patients to meet with a team of experienced surgeons with expertise in bone, joint, and muscle conditions. After surgery, patients receive close care from our treatment team, including rehabilitation medicine physicians, nurses, and experienced physical therapists with expertise in caring for patients with knee replacement surgery.

In Summary

Patients with knee osteoarthritis who still experience knee pain after receiving non-surgical treatments will be recommended for knee replacement surgery. This surgery is to replace worn or deteriorated knees with artificial knee implants. Some patients may also wonder how many types of knee replacements there are. Knee replacement surgery has 2 types for different indications and benefits: total knee replacement surgery (total knee arthroplasty: TKA) and partial knee replacement surgery (unicompartmental knee arthroplasty: UKA). The surgical method depends on the doctor’s judgment to achieve the best treatment results.

However, since partial knee replacement surgery (unicompartmental knee arthroplasty: UKA) is a difficult procedure, doctors performing this type of surgery need training and certification to confirm their excellent ability. kdms Hospital has skilled surgeons in partial knee replacement surgery (unicompartmental knee arthroplasty: UKA) who can perform surgery efficiently. With post-operative care and appropriate self-care guidelines for optimal recovery, we treat knee osteoarthritis patients to restore knee function as close to normal as possible.

An article by Prof. Boonchana Pongcharoen, M.D., Experienced Orthopedic Surgeon (Knee and Hip Replacement Surgery)

Q & A

For partial knee replacement surgery (unicompartmental knee arthroplasty: UKA), 70% of patients find that when one side is done, the non-operated side also improves. That’s because patients recover quickly and can use the operated side effectively within a short period, which relieves weight put on the non-operated leg. Therefore, the other leg has fewer risks of knee degeneration.

For patients who undergo total knee replacement surgery (total knee arthroplasty: TKA), they typically find that weight-bearing on the operated leg is more painful, so they put more weight on the other leg. This creates risk for knee osteoarthritis in the other leg that requires surgery.

Patients can have both knees operated simultaneously, depending on the surgeon’s recommendations. After simultaneous surgery on both sides, if the patient undergoes partial knee replacement surgery (unicompartmental knee arthroplasty: UKA), doctors will recommend staying in the hospital to observe post-operative symptoms for 1 day before returning home normally.

General post-operative symptoms such as pain, stiffness, or numbness around the knee will gradually disappear after surgery, depending on self-care and the surgical method.

Additionally, complications can occur in any surgery as they’re beyond control. The risk of bearing dislocation is at 0.003%, infection at 0.01%, bone fracture at 0.001%, and there is a very minimal risk of other serious complications such as heart or brain blood vessel blockages.

Knee osteoarthritis can be treated without surgery. Typically, non-surgical treatment is attempted before considering surgery, including weight reduction, exercises to build thigh muscles, and pain medications. However, when these methods don’t improve symptoms, doctors will recommend knee replacement surgery.

Consult symptoms before scheduling an appointment.