For decades patients were told a joint replacement lasts about fifteen years, and told to delay surgery accordingly so they would not outlive it. That advice shaped a generation of decisions, and it was based on data that is now old.
What the evidence actually shows
Two large systematic reviews published in the Lancet in 2019 pooled case series and national registry reports with more than fifteen years of follow-up. They found:
- Hip replacement: approximately 89 percent survival at 15 years, 70 percent at 20 years, and 58 percent at 25 years in the pooled case series. Registry data was more favourable still.
- Knee replacement: approximately 93 percent survival at 15 years, 90 percent at 20 years, and 82 percent at 25 years for total knee replacement.
The Australian Orthopaedic Association National Joint Replacement Registry, which records every joint replacement performed in Australia, reports cumulative revision rates for osteoarthritis of roughly 5 percent at 10 years and around 10 percent at 20 years for both hips and knees.
Put plainly: roughly nine in ten are still in place at twenty years.
Why the average is the wrong number
An average across all patients hides the thing that determines your answer, which is mostly your age.
Registry data consistently shows revision rates falling with increasing age at surgery. A replacement at 75 is very likely to outlast the patient. A replacement at 55 faces two more decades of loading, and the lifetime probability of needing a revision is substantially higher.
That is the real reason age comes up in the conversation, and it is a much better reason than the old "wait until you are old enough" advice.
What else moves the number
- Activity. Repetitive high impact loading increases bearing wear, and wear particles are the main driver of loosening over decades. This is why running is discouraged.
- Weight. Higher body weight increases load and is associated with higher revision rates.
- Implant choice. Most implants in wide use in Australia have good registry data. Some historical designs did not, which is precisely what registries exist to detect, and several were withdrawn because of it. See hip resurfacing for one example.
- Diagnosis. Replacement for inflammatory arthritis or post-traumatic arthritis carries different risks from replacement for straightforward osteoarthritis.
- Partial versus total. Partial knee replacement has a higher revision rate than total knee replacement, which is an accepted trade-off for a more natural feeling knee.
Should you delay because of it?
Generally no, and this is where the old advice did harm.
Waiting does not usually make the operation technically harder or the result worse. What waiting does cost is years of function, and it has its own consequences: reduced activity, loss of muscle and balance, weight gain, poorer cardiovascular fitness. Arriving at surgery deconditioned makes rehabilitation harder.
The reasonable position is that surgery is offered when symptoms justify it, not when a calendar says you have waited long enough. See am I too old for a knee replacement.
Where these figures come from
Every joint replacement performed in Australia is recorded in the national registry, along with every revision. That is why Australian survival figures are trustworthy: they are not a selected series from an enthusiastic unit, they are the whole country. Any figure quoted on this site is attributed on the page where it appears.
This page provides general information about a medical condition and a surgical procedure. It is not individual medical advice and does not replace consultation with a qualified practitioner. Outcomes vary between individuals and all surgery carries risk. A referral is needed for a consultation with Professor Daevyd Rodda; without one, you can start with the practice nurse practitioner, who can provide it.