When considering knee replacement surgery, many patients ask: How long do knee replacements last?
It’s a good question, but unfortunately, there’s no simple answer. A knee replacement lifespan depends on the patient’s health condition as well as many other factors. Also, most available data about knee replacement lifespan is based on patients who had surgery ten years ago or earlier; surgical techniques and technology have since improved.
“Because every patient’s situation is different, a surgeon can’t guarantee specific results,” said Donald Hohman, Jr., M.D. a fellowship-trained orthopedic surgeon in the joint replacement program at Texas Health Center for Diagnostics and Surgery (THCDS) in Plano. “Before scheduling surgery, every patient should have a frank conversation with their surgeon to get a realistic understanding of the expected lifespan of a knee replacement, relative to their medical situation. More importantly, the patient should understand what they can do to ensure their “new knee” lasts as long as possible.”
What affects the lifespan of knee replacements?
The question of a knee replacement’s lifespan has become more relevant in recent years, as knee replacement surgery becomes increasingly common among younger and younger patients.
According to a study released in 2018 at the annual meeting of the American Academy of Orthopedic Surgeons (AAOS), the mean age of knee replacement surgery declined from 68 years to 65.9 from 2000 to 2014. Another study looking at discharge rates for total joint replacement surgeries (knee and hip replacements) revealed the rate skyrocketed among patients who are younger, ages 45 to 64.
So why are younger people opting for the surgery?
For one thing, today’s Baby Boomers tend to be more active than their parents were at their ages. They’re less willing to accept pain that limits their ability to be active.
Also, while surgeons almost always advise patients to try more conservative treatments first – such as physical therapy, NSAIDs and rest -- advances have made knee replacement surgery less invasive and the recovery time shorter. That’s convincing some patients to opt for surgery at an earlier age, rather than waiting and contending with pain or disability for years.
Knee replacement lifespan is more critical when the patient is younger and thus has a longer life expectancy. Knee replacement surgery is very likely to last a lifetime for a person who undergoes knee replacement at age 70. For a person who has the surgery at age 50, the chance of requiring another surgery is considerably higher. That’s just a matter of statistics.
Most patients experience good results of knee replacement surgery for relief of their knee joint pain. However, no operation is successful 100% of the time. Failed joint replacement surgery occurs when a problem arises shortly after surgery, such as an infection or loosening of the device. In those cases, a second operation, also known as revision replacement surgery, may be necessary.
Knee replacement surgery has come a long way since it was first performed more than 50 years ago. It’s considered one of the most successful procedures in medicine, with more than 700,000 knee replacement surgeries performed annually in the United States, according to the Agency for Health Research and Quality.
Over the years, improvements in surgical materials and techniques have significantly increased the effectiveness of knee replacement surgery. Better physical rehabilitation after surgery helps speed knee replacement surgery recovery. Many surgeons also incorporate “prehab” measures before surgery to ensure good, long-lasting results. These may include prescribed exercises and encouraging patients to lose excess weight.
What is the average lifespan of knee replacements?
So how long will a knee replacement last? The standard reply that most doctors give – also the number you’ll find if you Google the question -- is that a knee replacement typically lasts 15-20 years. But the significance of that could be a bit confusing.
“Keep in mind that this data is based on surgeries done 10-20 years earlier; it can take a decade or longer to collect reliable data on current operations,” said Dr. Hohman. “As surgical techniques and technology improve, these numbers are likely to improve, too.”
Dr. Hohman suggests that a more accurate way to think about longevity is via the annual failure rates. Most current data suggest that both hip and knee replacements have an annual failure rate of 0.5-1.0%. This means that if you have your total joint replaced today, you have a 90-95% chance that your joint will last 10 years, and an 80-85% that it will last 20 years.
“As our surgical techniques and care improve, we expect many patients’ knee replacements will last longer, hopefully the rest of their lives,” said Dr. Hohman.
Signs of Wear and Tear
Patients who undergo knee replacement surgery will receive instructions from the medical team for symptoms and signs that may indicate that the replacement surgery needs revision or that the joint is worn out. The most common symptoms of a failed knee implant include decrease in joint function, knee instability, pain or swelling and stiffness in the joint. If the pain and swelling are persistent, that could indicate loosening, wear and tear, or an infection.
How You Can Maximize the Lifespan of You knee Replacement
Several factors – including age, weight, and activity level – will affect how long a replacement joint is likely to last.
So how can a patient maximize the lifespan of a knee replacement? First and foremost, follow the doctor’s recommendations carefully, before and after the surgery.
Your surgeon will provide detailed pre-operative instructions, which may include doing prescribed exercises or not taking certain medications in the days preceding the surgery. Follow these to the letter.
Be sure to move soon after surgery. Your care team will encourage you to sit up and walk on crutches or with a walker as soon as possible.
“We have people up and moving around as soon as they are able to do so after surgery,” said Dr. Hohman. “Often, patients are up within a few hours after surgery, and they’re starting rehabilitation therapy almost immediately.”
In some cases, the surgeon may prescribe blood thinners to help reduce the risk of blood clots. Patients may also be asked to perform breathing exercises and to increase their activity levels gradually. A physical therapist can guide you on how to exercise your new knee. You’ll likely continue physical therapy at home or at a clinic after you leave the hospital.
Talk to your health care team for guidance on how and when to resume normal activities. Understand what helps with recovery and what to avoid. Your goal is to stay as active as possible without overdoing it. Activities like golfing and biking are low impact and less likely to place too much stress on the joint. Avoid high-impact activities, like jogging, or sports that require jumping or contact.
Read more about knee replacement surgery services offered at Texas Health Center for Diagnostics and Surgery (THCDS) here. For more information, read this THCDS blog post, Everything You Need to Know About Knee Replacement Surgery.
FAQs
What is the lifespan of a knee replacement?
In 85% to 90% of people who have a total knee replacement, the knee implants used will last about 15 to 20 years. This means that some patients who have a knee replacement at a younger age may eventually need a second operation to clean the bone surfaces and re-fixate the implants.
What is the best age to have a knee replacement?
Currently, the average age of a patient who gets knee replacement surgery in the United States is around 65 years old. Generally, surgeons consider anyone under age 50 to be young for knee replacement. However, the best time for your replacement surgery is a question best answered in dialogue with your surgeon.