In this video, I'm going to look at what the research says about running after you've
had a knee replacement. And with regards to that, we're going to look at, first of all,
is it possible to run with a replaced knee? Second, are you looking for trouble? Is it
actually going to wear your joint out more quickly if you run? And then lastly, also look
at how you can increase your chances of being able to run after you had a knee replacement.
For those of you who don't know me, my name is Maryke. I'm one of the physiotherapists from
sports-injury-physio.com, where you can get online physiotherapy assessment as well as treatment for
your injuries. Have a look at the description of this video if you want a link to our website. What
does the research say about running after you've had a knee replacement? Well, let's first look at,
is it possible to run after a knee replacement? Yes, it is. So, there's a very interesting study
where they looked at ultra-marathon runners. It was the Ultra Trail du Mont Blanc race in France.
Now, this race varies between ... let me just get it right ... 55 kilometres and 300 kilometres,
each of these sections of the race. And what they wanted to see was, if there were runners who were
taking part with replaced joints. So, they looked at hip and knee replacements. And they also
wanted to see if these guys took part, was the dropout rate, that they can't complete the race,
higher for these guys or these people compared to the runners who didn't have joint replacements?
Now for knees, they were only four runners over the period between 2015 and 17 that took part
in this that had knee replacements. But three of them actually completed all the races. There was
only one that dropped out, which gives us a 25% drop-out rate. Now, this actually compares really
well with the regular people who didn't have knee replacements, which had a drop out rate of 19.6%.
Now, I will grant this, four runners is a very small sample size. So, it may mean that if we
had more runners with knee replacements, we may have seen a higher dropout rate,
but we could also have seen a lower dropout rate. The point to take from this is that it is
possible to run an ultra-marathon race without any trouble if you've had a knee replacement.
Because the other interesting thing is that the guys who had knee replacements
didn't report any adverse symptoms from their knee replacement either during training or during the
race or after the race, whereas several of the runners who had hip replacements did actually
complain of symptoms in their hip replacement, especially during the races and after it.
So, there may be a difference between hip and knee replacements and how well they tolerate running.
Then there's another study, where it's a review of 19 different articles that looked at physical
activity after you've had a knee replacement. And what they found was that in this big cohort of
people – it was over 4,000 knee replacements they looked at – there were 131 runners. Now
out of this group, only 23 went back to running. The part that they don't tell us in this study is,
why did only 23 go back? They don't tell us whether it was, they couldn't go back or
that they just didn't want to go back because it may be that they were worried, that they were
told they would wear their joint out, so they thought, ‘No, I'd rather cycle or something.’
So, all this research tells us, if we take it in combination, is that yes, it is possible
to run after knee replacement, but we don't know why so many people don't go back to it
and we don't know if it's safe. So then, that brings us to the second question.
Will you wear your replaced knee joint out more quickly if you do run versus if you don't run?
So surprisingly, I thought the research would say yes, because all my physio career
I've been told that high-impact activities wear replaced joints out more quickly. But actually,
the research is a bit lacking in this department. The expert opinion is that yes,
high-impact activities may wear the joint out more quickly, but it also seems that
expert opinion is starting to change, so this is interesting. So, to look at this, I looked at … I
took the research that we do have and divided it into three sections. For the first section,
we're looking at general physical activities. So, not just high impact, but everything you
do in a day. Secondly, we're going to look at high-intensity activities like HIIT classes,
but this can be cycling or high impact. And then lastly, we'll look at high impact specifically.
So, if we look at people who do ... or people who are really active after they
have a hip replacement versus ones who are quite sedentary and don't do much.
There was a large review, and this review was in 2021, so it's really recent – by the way,
all the research articles are in the description of this video, if you want to have a look at it –
where they looked at physical activity in people. And they found mixed results. Some studies showed
that the more physically active you are, the more likely you will be to need another knee
replacement more quickly. But then the opposite was also found in other studies, which showed that
if you're sedentary, you're going to need a knee replacement more quickly than active people.
So we can't make a judgment with regards to that at the moment. But what I will say on this topic
is, remember why you're getting a knee replacement in the first place. It's because you want to
be active. So, what's the use of having a knee replacement, then just sitting on your bottom?
And then secondly, if we think of all the benefits that physical activity holds for you with regards
to cardiovascular health, your heart health, preventing diabetes or improving diabetes,
several chronic conditions, mental health, then it's not really an option to be sedentary. If you
want to have a long, healthy life, you have to be active after you have your knee replacement. Then,
if we think about high-intensity activity. Now, it's important to understand that high intensity
doesn't mean high impact. It can be cycling HIIT classes or swimming HIIT classes, intervals,
that type of thing as well. There's one research study that looked at this, and they didn't divide
it up into high-impact, low-impact HIIT classes or activities. But what they showed was that there's
really no research to show that high-intensity activity is bad for a replaced knee joint.
So, it answers part of our question, but not really all of our question. All it means is
that you can do high-intensity activities without negatively affecting your joints, likely. It's
only one study, so we need more research on that. Now, we get to the section that we're actually
interested in. Is there evidence that high-impact activities, like running, will increase the wear
on your joint and mean that you've got to have a replacement more quickly or earlier on? Now,
there's a massive lack of research into this area with regards to knee replacements. There
is a study that looked specifically at hip replacements, and what they found was that,
yes, activities that load the joints more can actually increase the risk of earlier revision.
Now, what they found with that was, there's several factors that load the joint, it's
not just the type of activity. So, yes, type of activity plays a role, but also your body weight,
the control you have, or your technique while you're doing the activity. And what they found is
that novice runners, so, if you've not run before and you take up running, you actually load your
joints more than somebody who's experienced, who’s already got their running style down to a tee.
And there was strong evidence that if you have poorer motor control – that's how well
you control your body when you move – that loads the joint more. So, it's not just as simple as
what activity you're doing, it's also the other factors around that that can load the joint more.
But now we know from the Mont Blanc Ultra Race study that runners with replaced hips
and runners with replaced knees seem to fare differently during endurance events and that
knees and hips may not be comparable. So, this study's results may not actually apply
to knee joints that's been replaced. So, the only other study on this subject is
one where they looked at, what is the expert opinion? And they looked at 150
surgeons who specialise in knee replacements and asked them about what activities they advise
patients is safe to return to at what interval or point after surgery. And interestingly enough, 68%
of the experts agreed that people could go safely back to running or jogging after six months.
Now, to be specific with this, 60% said they could jog on a road after six months,
54% said they could run on a treadmill, and 51% said they could do any type of running.
Now, they didn't tell us what they see is the difference between jogging and running,
because to me there's not that much difference, but I'm going to assume
that jogging is slow running and with running they meant high-intensity running.
So yes, that's interesting, that's definitely new. Because when I first studied,
expert opinion from knee replacement surgeons was, stay away from high-impact activities if
you want to make your joints last. So, it seems that actually that is now changing.
Now for context here, it's not that these experts felt you could go back to any high-impact sports.
Squash, for instance; they all agreed that it was a bad idea to ever play squash after you
have a knee replacement. And that's just because that's really high force, really stop-start.
So, the fact that they feel running is safe means that they have actually thought about this
and have experience in this. How can you increase your chances of running after you've had a knee
replacement? Now, the research shows that you are more likely to go back to running
after your knee replacement if you remain active up until when you have your knee replacement.
Of course, you won't be able to run necessarily before you have your knee replacement. But being
active means things like swimming, cycling, just doing strength training. And there's a few reasons
why this can help. One is that you're in the habit of exercise then, so it's easier to go back to it.
Second, if you stay active, you keep your muscles strong and you will have better circulation,
more little blood vessels, and all of that helps with healing, so it may be that your
results actually turn out better. So, try to stay active, do whatever you can, even if it feels like
nearly nothing compared to what you used to do; just try to be as active as you can. Then
second is, don't rush back into running. Remember, although the experts are agreeing – well, 60% of
them agree – that you can go back to running, it's only after six months. And the reason for this is,
one, your bones have to heal. So, there where that orthosis has gone in, the bone has to settle down
and become strong again, and that takes a very long time. So, that's part of the reason why six
months is a good time. Then also, you need time to build your strength and endurance in your muscles,
because your joint is new, but the muscles aren’t strong necessarily. And when you run,
it's not just your joint that needs to take all the strain, your muscles have to absorb large
amounts of it. And the weaker your muscles, the more strain the joint will take. And remember,
earlier on we also spoke about some of the research for hip replacements showing that
you load your joints more if you have poor running technique, and making sure that you've got good
control with your exercises will help with that as well. Then thirdly, it's kind of hand-in-hand
with that: Build your base. You have to have really good muscle strength, really good control
to ensure that your knee joint takes as little force as possible while you're running. So,
really put the effort in and don't just do the simple exercises that you're being given
in hospital, but build it up to where you can do the things you need to be doing to be able to run.
And a physiotherapist can help you assess that and figure that out. Then, fourth is,
you may have to adapt your training plan compared to what you were used to doing.
So, often less is more, that you allow for more recovery between run sessions, that you don't do
just, like, junk miles just because you want to be running, that you do really targeted sessions. So,
fewer running sessions, but working around the goal that you want to achieve with them. And these
days there are more and more training plans that's coming out like that, even for people without knee
replacements, because what they figured out now is, like even for marathon training, where it was
always about the volume you could train, now people understand that, no, that doesn't suit
everybody's body. You have to go according to what the body wants, and people are training as
little as two to three times a week and still managing to run marathons at decent paces.
So, you may have to reassess your goals and your running volumes if you've had a knee replacement.
Be guided by what your knee’s telling you, and go as slowly as you have to to get yourself back.
And then lastly, it's all about minimizing the load on that joint, especially if you want it
to last as long as possible. And there are several things you can do. So, we've already spoken about
strength training and control training, but then also, thinking about your training plan,
not pushing far into exhaustion when you're running, because then you lose your form,
so the joints will load more. Running terrain: So, running really steep downhills or long downhills
places a lot more force onto the joints, as well as very uneven terrain or cambers.
So, it may be about choosing your terrain properly, and perhaps running on softer surfaces
rather than road the whole time. But also, running shoes are really important for that.
So, Hokas are brilliant at providing shock absorption, because they've got these thick soles,
but stability; they're a really the combination of those two things. Because previously
we would get cushioned shoes, but they would be really unstable. So, look at what may be the best
running shoe to provide the cushioning you need. What am I leaving out? Yes. And then an important
one is to keep your weight within a healthy weight. Now, you've got to be mindful that if you
don't take in enough calories or you diet quite fiercely over a long period of time,
you may end up actually causing your bones to be weaker, because you don't have enough energy
to rebuild them after each training session. So, it's not about severely limiting your diet, but
it's about just maintaining a healthy diet. So, eating all the calories you need to replace what
you burn when you train, but try not to overeat, try not to be heavier than what you should be.
Uhmm ... what am I leaving out? So, to summarize, Ah! Actually, there's a last important one:
If you've not run before you had your knee replacement, so, in the years going up to it, you
never really ran, you’re new to running, and you think, ‘Ah, now that I've had my knee replaced,
I want to take up running!’ The research or the experts seem to suggest that that's not a great
idea. And the reason for that is that somebody who doesn't have experience in running usually has a
poorer technique than somebody who's experienced in running. And we know that, with hips at least,
they've shown that the joints get loads ... load more if you don't have such good technique. So,
if you’re new to running, you've never run before, it's not really a great idea to take up running
after you've had a knee replacement. So, to summarize, we've got to stay active with any type
of exercise that you will tolerate until you have your knee replacement. Then, do not rush back into
running too quickly; you need to wait at least six months for your bones and everything to settle.
Strength train and work on control before you go back to running. And don't start running if you're
new to it, and minimize the load on the joint through thinking about your running terrain,
your running distances, your training program not increasing too quickly, the right shoes,
and keeping your weight down but not dieting too severely because then you can affect your
bone health. Excellent! Let me know if you've got any questions, and remember, if you need any help
with a training plan or you want an assessment of an injury, you’re welcome to consult one of
the team via video call – the link to the website is in the description of this video. Take care!