A common question people considering knee surgery ask is, “How long do knee replacements last?” In February 2019, researchers published exciting news for people with osteoarthritis of the knee, especially those considering total knee replacement.
The study, published in The Lancet, reported eight out of 10 knee replacements last as long as 25 years. This is significant for a number of reasons:
- Twenty-five years is a decade longer than previously thought.
- The research will help patients and doctors better determine if or when to have knee replacement surgery.
- Knee replacement and revision surgeries are on the rise (Arthritis Foundation).
- By 2030, primary total knee replacement surgery is projected to grow by up to 189 percent (American Academy of Orthopaedic Surgeons).
Total Knee Replacement Estimate Raised From 15 to 25 Years
Prior to the study, 15 years had typically been cited as the length of time patients should expect an artificial knee joint to last. Fifteen years had been given as a rough estimate because there was no scientific evidence to prove the actual time period joints lasted after joint replacement surgery.
The researchers followed nearly 500,000 patients who had undergone joint replacement surgery over the past 25 years. Specifically, the results showed that:
Among total knee replacements
- 93 percent lasted 15 years
- 90 percent lasted 20 years
- 82 percent lasted 25 years
Among partial knee replacements
- 77 percent lasted 15 years
- 72 percent lasted 20 years
- 70 percent lasted 25 years
Knee Replacement Revision Surgery
After a patient has had joint replacement surgery, sometimes a second surgery, called a revision, is needed to replace the joint. Reasons for revision surgery vary and may include infection in the knee, loosening of the implant, or wear-and-tear of the artificial joint.
The results of the study may reduce the frequency of revision surgeries (which can be more complex and less successful than initial joint replacement surgery). Additionally, younger, more active people may consider joint replacement as a viable option, knowing there may be less chance of needing revision surgery in the future.
A Positive Impact on Patients and the Healthcare System
The study is not only useful for those considering total knee replacement, it also impacts healthcare more widely:
- The population of older adults in the U.S. is increasing at an unprecedented rate, and people are living longer due to advances in healthcare.
- Joints are some of the first parts of the body to wear, and increasing numbers of people may need knee replacement surgery.
- Knowing artificial knees last longer than believed may help the U.S. healthcare system better manage its resources.