How Long Does a Knee Replacement Last?

Knee replacement surgery gives hope to people with severe arthritis or knee injury. It can restore mobility which is essential in moving around freely and enjoying the pleasure of walking and running.

Thanks to the new medical technology  this surgery is very beneficial, especially for older people and athletes, among others, who are suffering from joint diseases or knee injuries caused by accidents.

Harvard Health Publishing Senior Faculty Editor, Dr. Robert Shmerling, reported that in the United States, over 600,000 knee replacements are performed by surgeons each year⁽¹⁾. This data shows how common knee injuries are and also reflects the reliability of the procedure.

But how long does this knee replacement last? That’s the question worth asking. If an individual plans to go through a knee replacement procedure, they must get some background information first.

Knee Replacement Won’t Last Forever

No operation is 100% successful. This is the truth that everyone must accept. Meaning, if a patient undergoes a knee operation today, there is no guarantee that it will be the last time that they go through the procedure.

Many factors determine how long a knee replacement lasts. Factors include surgical technique, surgeon’s experience, patient’s age, weight, and activity level.

Obesity is considered a risk factor for the failure of replaced joints. Overweight patients may require another surgery sooner than those with average weight.

Nevertheless, the knee replacement operation can still be highly effective for obese people despite the risks associated with their circumstances.

Dr. Robert Shmerling noted that based on his training education in the 1980s and 1990s, 90% or more of the knee or hip replacements last at least 10 to 15 years. The same figure may be estimated today, or even better than that, he added⁽²⁾.

The success of knee replacement procedures, especially on how long the new joint will last, depends on several factors.

Factors include preparation before the surgery, materials in the replacement, surgical techniques and anesthesia, and physical rehabilitation.

How Long Does a Knee Replacement Last?

Given that medical technologies have evolved since the 1990s, one may think that knee replacement surgeries may also have improved, and that may be true.

However, Dr. Shmerling, in his article published on Harvard’s website, said that it is difficult to predict how long a knee replacement will last for several reasons⁽³⁾.

1. It can take at least one decade to gather data on past operations to estimate the success of future surgeries.
2. Performing surgery on younger patients is another challenge. They can still be highly active even in their 50s and 60s, and more joints may still develop.
3. Age is a critical factor as well. People above 50 years old with a life expectancy of 15 years, for example, have a better chance of avoiding future operations than other younger groups aging 30 years old or below and with a life expectancy of 30 years. This is because of the risks associated with the activities of the younger people, which can result in subsequent knee operation.
4. Younger patients seem to be more active and put more stress on the replaced joint, affecting how long the replacement would last. Some surgeons advise these age groups to put off surgery even if they have to go through pain, stiffness, and reduced mobility.

Recent Data Shows Reliability of Knee Replacement

While knee replacement will not last forever, it does not mean that the procedure will not benefit patients in the long run. A study published in the April 2017 edition of the medical journal⁽⁴⁾, The Lancet, stated the following research findings:

1. Among nearly 55,000 patients who had knee surgeries, only 3.9% required subsequent operation within ten years, and 10.3% within 20 years.
2. Among patients over 70 years old, the lifetime risk of having a second surgery was about 5%. The same risk is much higher among younger patients, especially men with a 35% probability of subsequent operation in their early 50s. Thus, the researchers noted that age is a critical factor.

More Studies Are Needed to Evaluate Progress

The current data available is not enough to give doctors and patients realistic expectations in knee replacement surgery. More studies are needed to determine whether the results of knee operations are getting better over time.

People who consider undergoing knee replacement surgery are advised to discuss the matter with a reliable surgeon and ask questions about risks, recovery time, and how long the replacement would probably last.

A clear sign that one needs to consult a surgeon is experiencing knee popping sounds accompanied by swelling and pain. The attending physician can examine the knee to make a proper diagnosis.

In the case of people with arthritis, there are complementary and alternative treatments available. These include⁽⁵⁾:

1. Acupuncture
2. Anthocyanidins
3. Aromatherapy
4. Antler velvet
5. Andrographis paniculata
6. Alexander technique

Reference

1. Harvard Health Publishing, Harvard Medical School, How Long Will My Hip or Knee Replacement Last? Retrieved from

https://www.health.harvard.edu/blog/how-long-will-my-hip-or-knee-replacement-last-2018071914272

1. Ibid.
2. Ibid.
3. Bayliss, Lee, et. al (2017), 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, retrieved from https://pubmed.ncbi.nlm.nih.gov/28209371/
4. Versus Arthritis, Types of Complementary Treatments, retrieved from ://www.versusarthritis.org/about-arthritis/complementary-and-alternative-treatments/types-of-complementary-treatments/