Knee replacement surgeryis a treatment for severeknee arthritis. Most patients understand that knee replacements can wear out over time, but exactly how long is a knee replacement supposed to last?Peter Dazeley / Getty ImagesKnee replacements eventually wear out. Because theknee replacement implantsare made of metal and plastic, over time, these materials begin to wear, just like the rubber on your car tires. While knee replacements are designed to last a long time, they will not last forever.What Studies ShowThe good news is that studies show that common types of knee replacements can last more than 20 years. One study on long-term outcomes of a commonly used knee and hip replacements published in 2017 found the implant to still be functioning in about 90% of patients 20 years after being implanted. This is certainly one of the better reports, and other studies have not necessarily shown that level of success. However, the goal of a knee replacement should be to achieve several decades of a functioning knee.You should remember that while some patients may have knee replacements that last several decades, other patients may require a repeat knee replacement just a handful of years after their surgery. Revision knee replacement (a second knee replacement) can be a major undertaking that can have less predictable results than an initial knee replacement.An older report from 2001 found that only about 2% of knee replacement surgeries required a second surgery within five years of the initial knee replacement.More recent data suggest a 10-year revision rate of about 8% to 9%.Factors Affecting the LongevityMany studies have been done to determine how long a knee replacement will last. With hundreds of different types of knee replacements and countless different types of patients, there is no rule to how long a knee replacement will last in a particular individual.Implant manufacturers are constantly striving to create a better implant that will last longer. Some of these implants have only been used for a handful of years, and determining whether or not they will last longer is a question only time can answer.Some of the factors that seem to influence the longevity of knee replacement implants include:Age of the Patient:Younger patientsrequire more years out of their knee replacement. On top of that, younger patients tend to be more active. Therefore, patients who have knee replacement in their 50s or younger can usually expect to require arevision knee replacementin their lifetime.Patient Activities:Someactivities may not be appropriatefor patients with a knee replacement. While these activities may not be painful or difficult, they may be placing excessive stress on the knee replacement, causing the parts to wear out more quickly.Patient Weight:The more an individual weighs, the more stress that is placed on the joint replacement implant. Maintaining a normal body weight is critically important when trying to make a joint replacement last. Appropriate exercises can be helpful in maintaining a healthy knee replacement.Avoiding Complications:This may sound obvious, but there are some specific medical conditions that can lead to complications affecting the joint replacement. Patients having invasive medical procedures (including dental work) may require antibiotic treatment to prevent bacteria from getting into the joint replacement.Patients withosteoporosisshould ensure they are being adequately treated, as a fracture in the bone around a joint replacement can affect the functioning of the implant.A Word About the Newest Knee Replacement ImplantsOne temptation of patients and surgeons alike is to be attracted to the newest knee replacement on the market. Undoubtedly, this implant will claim to function better and last longer than other knee replacements. While these newer implants may be better, it is also important to understand they do not have long-term data on how well these implants will function over time.Ask any orthopedic surgeon about the implants they have seen come and go over the course of their career. Just because an implant is newer does not necessarily mean it is better.Patients and surgeons should try to find an appropriate balance between modern design and not being a “test” patient. Your surgeon can help guide you to an appropriate knee replacement that is best for you.Frequently Asked QuestionsKnee replacement implants are made of metal and plastic. The metal used is typically titanium- or cobalt-chromium-based alloys. The plastic is usually medical-grade polyethylene. Ceramics or ceramic and metal mixtures, such as oxidized zirconium, are sometimes used as well.It might be possible that a knee replacement can last 30 years. However, the typical lifespan of a knee implant is 15 to 20 years. Newer materials and designs of artificial knee joints make it possible for the replacement joint to last longer. A simulation of 30 years of normal activity suggests that implants made with a combination of oxidized zirconium and highly cross-linked polyethylene might be able to last that long.Signs that your knee replacement is wearing out include pain, decreased joint function, swelling or stiffness in the area, and joint instability. If you have an artificial knee and experience any of those symptoms, talk to your doctor.
Knee replacement surgeryis a treatment for severeknee arthritis. Most patients understand that knee replacements can wear out over time, but exactly how long is a knee replacement supposed to last?
Peter Dazeley / Getty Images
Knee replacements eventually wear out. Because theknee replacement implantsare made of metal and plastic, over time, these materials begin to wear, just like the rubber on your car tires. While knee replacements are designed to last a long time, they will not last forever.
What Studies Show
The good news is that studies show that common types of knee replacements can last more than 20 years. One study on long-term outcomes of a commonly used knee and hip replacements published in 2017 found the implant to still be functioning in about 90% of patients 20 years after being implanted. This is certainly one of the better reports, and other studies have not necessarily shown that level of success. However, the goal of a knee replacement should be to achieve several decades of a functioning knee.
You should remember that while some patients may have knee replacements that last several decades, other patients may require a repeat knee replacement just a handful of years after their surgery. Revision knee replacement (a second knee replacement) can be a major undertaking that can have less predictable results than an initial knee replacement.
An older report from 2001 found that only about 2% of knee replacement surgeries required a second surgery within five years of the initial knee replacement.More recent data suggest a 10-year revision rate of about 8% to 9%.
Factors Affecting the Longevity
Many studies have been done to determine how long a knee replacement will last. With hundreds of different types of knee replacements and countless different types of patients, there is no rule to how long a knee replacement will last in a particular individual.
Implant manufacturers are constantly striving to create a better implant that will last longer. Some of these implants have only been used for a handful of years, and determining whether or not they will last longer is a question only time can answer.
Some of the factors that seem to influence the longevity of knee replacement implants include:
A Word About the Newest Knee Replacement Implants
One temptation of patients and surgeons alike is to be attracted to the newest knee replacement on the market. Undoubtedly, this implant will claim to function better and last longer than other knee replacements. While these newer implants may be better, it is also important to understand they do not have long-term data on how well these implants will function over time.
Ask any orthopedic surgeon about the implants they have seen come and go over the course of their career. Just because an implant is newer does not necessarily mean it is better.
Patients and surgeons should try to find an appropriate balance between modern design and not being a “test” patient. Your surgeon can help guide you to an appropriate knee replacement that is best for you.
Frequently Asked QuestionsKnee replacement implants are made of metal and plastic. The metal used is typically titanium- or cobalt-chromium-based alloys. The plastic is usually medical-grade polyethylene. Ceramics or ceramic and metal mixtures, such as oxidized zirconium, are sometimes used as well.It might be possible that a knee replacement can last 30 years. However, the typical lifespan of a knee implant is 15 to 20 years. Newer materials and designs of artificial knee joints make it possible for the replacement joint to last longer. A simulation of 30 years of normal activity suggests that implants made with a combination of oxidized zirconium and highly cross-linked polyethylene might be able to last that long.Signs that your knee replacement is wearing out include pain, decreased joint function, swelling or stiffness in the area, and joint instability. If you have an artificial knee and experience any of those symptoms, talk to your doctor.
Frequently Asked Questions
Knee replacement implants are made of metal and plastic. The metal used is typically titanium- or cobalt-chromium-based alloys. The plastic is usually medical-grade polyethylene. Ceramics or ceramic and metal mixtures, such as oxidized zirconium, are sometimes used as well.
It might be possible that a knee replacement can last 30 years. However, the typical lifespan of a knee implant is 15 to 20 years. Newer materials and designs of artificial knee joints make it possible for the replacement joint to last longer. A simulation of 30 years of normal activity suggests that implants made with a combination of oxidized zirconium and highly cross-linked polyethylene might be able to last that long.
Signs that your knee replacement is wearing out include pain, decreased joint function, swelling or stiffness in the area, and joint instability. If you have an artificial knee and experience any of those symptoms, talk to your doctor.
5 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Bayliss LE, Culliford D, Monk AP, et al.The effect of patient age at intervention on risk of implant revision after total replacement of the hip or knee: a population-based cohort study.Lancet. 2017;389(10077):1424–1430. doi:10.1016/S0140-6736(17)30059-4Agency for Healthcare Research and Quality.Total knee replacement: summary. Evidence Report/Technology Assessment: Number 86.Yong TM, Young EC, Molloy IB, Fisher BM, Keeney BJ, Moschetti WE.Long-term implant survivorship and modes of failure in simultaneous concurrent bilateral total knee arthroplasty.J Arthroplasty. 2020;35(1):139-144. doi:10.1016/j.arth.2019.08.011Daly CG.Antibiotic prophylaxis for dental procedures.Aust Prescr. 2017;40(5):184–188. doi:10.18773/austprescr.2017.054PR Newswire.Smith+Nephew announces new milestone with its OXINIUM Advanced Bearing System implants surpassing two million procedures.
5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Bayliss LE, Culliford D, Monk AP, et al.The effect of patient age at intervention on risk of implant revision after total replacement of the hip or knee: a population-based cohort study.Lancet. 2017;389(10077):1424–1430. doi:10.1016/S0140-6736(17)30059-4Agency for Healthcare Research and Quality.Total knee replacement: summary. Evidence Report/Technology Assessment: Number 86.Yong TM, Young EC, Molloy IB, Fisher BM, Keeney BJ, Moschetti WE.Long-term implant survivorship and modes of failure in simultaneous concurrent bilateral total knee arthroplasty.J Arthroplasty. 2020;35(1):139-144. doi:10.1016/j.arth.2019.08.011Daly CG.Antibiotic prophylaxis for dental procedures.Aust Prescr. 2017;40(5):184–188. doi:10.18773/austprescr.2017.054PR Newswire.Smith+Nephew announces new milestone with its OXINIUM Advanced Bearing System implants surpassing two million procedures.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Bayliss LE, Culliford D, Monk AP, et al.The effect of patient age at intervention on risk of implant revision after total replacement of the hip or knee: a population-based cohort study.Lancet. 2017;389(10077):1424–1430. doi:10.1016/S0140-6736(17)30059-4Agency for Healthcare Research and Quality.Total knee replacement: summary. Evidence Report/Technology Assessment: Number 86.Yong TM, Young EC, Molloy IB, Fisher BM, Keeney BJ, Moschetti WE.Long-term implant survivorship and modes of failure in simultaneous concurrent bilateral total knee arthroplasty.J Arthroplasty. 2020;35(1):139-144. doi:10.1016/j.arth.2019.08.011Daly CG.Antibiotic prophylaxis for dental procedures.Aust Prescr. 2017;40(5):184–188. doi:10.18773/austprescr.2017.054PR Newswire.Smith+Nephew announces new milestone with its OXINIUM Advanced Bearing System implants surpassing two million procedures.
Bayliss LE, Culliford D, Monk AP, et al.The effect of patient age at intervention on risk of implant revision after total replacement of the hip or knee: a population-based cohort study.Lancet. 2017;389(10077):1424–1430. doi:10.1016/S0140-6736(17)30059-4
Agency for Healthcare Research and Quality.Total knee replacement: summary. Evidence Report/Technology Assessment: Number 86.
Yong TM, Young EC, Molloy IB, Fisher BM, Keeney BJ, Moschetti WE.Long-term implant survivorship and modes of failure in simultaneous concurrent bilateral total knee arthroplasty.J Arthroplasty. 2020;35(1):139-144. doi:10.1016/j.arth.2019.08.011
Daly CG.Antibiotic prophylaxis for dental procedures.Aust Prescr. 2017;40(5):184–188. doi:10.18773/austprescr.2017.054
PR Newswire.Smith+Nephew announces new milestone with its OXINIUM Advanced Bearing System implants surpassing two million procedures.
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