This is one of the most common questions asked in the rooms, usually by someone in their fifties who has been told they are “too young” and has not been told what that actually means.
It is a fair question with a genuinely useful answer, because the evidence here is unusually clear.
What “too young” is really about
Age itself is not a barrier to a hip or knee replacement. There is no threshold below which the operation is prohibited or above which it becomes obligatory.
What changes with age is the chance of needing a second operation (a revision) later in life. An implant is a mechanical thing in a biological setting. The longer you live with it, and the more you ask of it, the greater the chance it will eventually need attention.
The numbers, which you are entitled to have
A large population-based study published in The Lancet in 2017 followed patients after hip and knee replacement and calculated the lifetime risk of needing the joint revised, by the age at which the first operation was done:
- Surgery after age 70: lifetime revision risk approximately 5%.
- Surgery in the early fifties: rising to as much as 35% for men (95% confidence interval 30.9 to 39.1), with women approximately 15% lower in the same age band.
- Among patients who had surgery under 60 and did go on to need a revision, the median time to that revision was about four and a half years.
That last figure is the one that tends to surprise people. Where revisions occurred in younger patients, they often occurred relatively early rather than decades down the track.
The authors of that study concluded that these data “should be offered to patients as part of the shared decision making process”. Publishing them here is doing what the paper asks. It is not an argument against having surgery young; it is the information required to make that choice properly.
How to read a 35% risk
Two things are worth holding together.
The first is that a 35% lifetime risk is substantial and deserves respect. It is not a footnote.
The second is that even in that highest-risk group, roughly two in three people never needed a revision at all, and a revision, while a bigger operation than a first replacement, is an operation that can be done.
So the honest position is neither “you are too young, come back in fifteen years” nor “age doesn’t matter”. It is that a replacement done at 52 is a different proposition from one done at 72, and the conversation should reflect that.
The cost of waiting is real too
The argument for delay is easy to state and easy to overstate. Waiting is sensible while the joint remains genuinely manageable, while exercise, weight management and simple measures are still giving you a life you are content with.
Waiting stops being sensible when it means:
- you have stopped exercising, and lost muscle and fitness as a result
- you have gained weight because you can no longer move comfortably
- you are taking pain medication most days
- you have given up work, sport or travel you would otherwise still be doing
Arriving at surgery deconditioned makes the operation harder and the recovery slower. And the years spent waiting are years you do not get back. “Wait as long as possible” is bad advice; “wait as long as is reasonable” is the honest version.
What this means in practice
If you are in your fifties with arthritis that is limiting you, the useful questions are:
- Has non-surgical treatment had a genuine, properly supervised trial? Exercise in particular has the best evidence of anything short of surgery, and it is frequently attempted half-heartedly rather than properly.
- How much of your life is the joint currently taking?
- Are you comfortable with a meaningfully higher chance of needing a second operation in exchange for getting those years back now?
Nobody can answer the third question for you, and no surgeon should pretend the risk is smaller than it is. What can be done is to make sure you are choosing with the real numbers in front of you.
If it would help to talk it through (including the possibility that the answer is “not yet”) that is a reasonable reason to come in.