Preparing for a Knee Replacement: the Weeks Before Surgery
What to do in the weeks before a knee replacement — strengthening the leg, working on the straightening, getting the house ready, health matters worth sorting first, and what to arrange before you go in. By Perth orthopaedic surgeon Dr Rhys Clark.
Most of the attention before a knee replacement goes on the operation itself, which is the part you have least influence over. The weeks beforehand are almost entirely yours, and they are worth using.
This page covers the preparation that makes a difference — conditioning the leg, sorting the house out, dealing with the health matters that affect healing, and arranging the things that are much harder to organise once you are home on crutches.
For the hospital process — the anaesthetic assessment, what to bring, what happens on the day — see pre-op information. This page is about everything before that.
How much does preparation actually change things? Honestly: less than some sources suggest, and it is better to say so. The research supports a faster early recovery in patients who go in stronger, rather than a better result at a year. What it reliably buys is strength you would otherwise be building from a lower base while also recovering from surgery, and a much clearer idea of what is coming. Both are worth having. Neither is a reason to put the operation off.
Strengthening the leg
The thigh muscle shuts down after a knee replacement. That is true regardless of what you do beforehand — but it shuts down from wherever it started, and the stronger the quadriceps going in, the more is left to work with afterwards.
A knee that has been painful for years has almost always lost quadriceps strength already, often more than the person realises, because the loss happened slowly.
What to work on:
- Quadriceps. Straight leg raises, inner-range work, sit-to-stands from a firm chair. This is the priority
- Hips and buttocks. The muscles that keep you steady on one leg. Standing hip abduction, bridges, step-ups within comfort
- Arms. Genuinely important and almost always forgotten. Crutches and a walking frame are worked by the arms, and getting out of a chair or a bed in the first fortnight is largely an upper-body task. Chair push-ups and any resistance work you can manage
- The other leg. It is about to do considerably more than its share
What to avoid: anything that leaves the knee swollen and sore the next day. The aim is to arrive stronger, not to arrive irritated. An arthritic knee has limits, and pushing into them for six weeks achieves nothing useful.
Low-impact conditioning — a stationary bike, pool walking, swimming — builds general fitness without loading the joint the way walking distances does. Being reasonably fit going into an operation and an anaesthetic is worth something in itself.
If you can get a few sessions with a physiotherapist to set the programme up, that is the best version of this. Exercise and physiotherapy for knee arthritis covers what that work looks like more generally.
Work on the straightening now
This is the highest-value item on the page and the least obvious.
How far your knee bends and straightens before surgery is the best available predictor of how far it will bend and straighten afterwards. A knee that has been sitting with a fixed bend for years has short hamstrings, a tight capsule and shortened ligaments behind it. The operation can address the joint. It cannot lengthen soft tissue that has been short for a decade — that is rehabilitation work, and any of it done beforehand is work you do not have to do while also recovering from surgery.
Lie flat with the heel propped on a rolled towel so the calf is supported and the knee hangs free. Let gravity pull it towards straight. Ten to fifteen minutes, several times a day.
It is uncomfortable and it is worth it. Range of movement after a knee replacement explains why extension matters more than bend, and why it is the harder of the two to recover afterwards.
Health matters worth sorting first
Several of these take weeks, which is why they belong here rather than in the last few days.
Stop smoking. Smoking impairs the healing of skin and soft tissue and increases the risk of both infection and anaesthetic complications. Two weeks of abstinence before surgery reduces that risk and longer reduces it further. Your GP can help with what is available.
See a dentist if you have a known problem or are overdue. Bacteria from a dental infection can reach a new joint through the bloodstream. It is an uncommon problem and an easy precaution.
Check your skin. Cuts, ulcers, infected ingrown toenails, tinea between the toes or broken skin anywhere on the leg are all reasons to let the rooms know before the day — they can mean postponing, and finding out on the morning of surgery is far worse than finding out three weeks earlier.
Get your general health reviewed. Diabetes control, blood pressure, iron levels and anaemia all influence how surgery and recovery go, and your GP can address them with a bit of notice. Bring a current list of your medications and supplements, including anything bought over the counter — some need stopping before surgery and some do not.
Weight, where it is relevant, is raised directly and discussed as a conversation rather than a hurdle. Weight and knee load sets out the mechanics of why it matters.
Getting the house ready
Do this before you go in. It is much harder afterwards, and the first fortnight is when it counts.
Remove the trip hazards. Loose rugs, trailing cords, the pile of things at the bottom of the stairs. A walking aid and a rug are a bad combination.
Sort out one good chair. Firm, with arms, and high enough that you can stand up without hauling yourself out of it. A low, soft armchair is the enemy for the first few weeks. Have somewhere beside it to prop the leg with the heel supported.
Think about the bathroom. A shower you can get into without a high step over a bath edge. A non-slip mat. A rail or a shower stool if there is any doubt — occupational therapy can advise, and getting this right prevents the single most common domestic accident after joint surgery.
Bring things up to waist height. Kitchen items, clothes, whatever you use daily, so nothing needs a deep reach or a bend.
Check how you get in the front door. Steps, a gate, a long path from where the car can stop. Work out the plan before the day you arrive home.
Cook and freeze. A fortnight of meals you do not have to stand up to make is worth more than it sounds.
Things to arrange
- Someone at home for at least the first week, ideally longer. Not necessarily full time, but available
- A lift home from hospital, and lifts to early appointments — you will not be driving for around six weeks
- Your physiotherapy, booked in advance for after discharge rather than organised once you are home. Ask which physiotherapist, and when the first appointment should be
- Crutches or a frame, fitted to your height beforehand. Your physiotherapist can size them
- Ice. Several packs, so there is always one in the freezer. You will use them more than you expect
- Time off work discussed and agreed, with a realistic figure rather than an optimistic one. Desk work often resumes earlier; physical work takes considerably longer and is worth discussing specifically
- Your medication supply, so you are not sorting out a prescription in the first week home
Knowing what is coming
The part of preparation that is hardest to measure is probably the most useful.
The first fortnight after a knee replacement is difficult. The knee is swollen and sore, sleep is broken, progress is slow enough to be invisible day to day, and a good many people feel flat somewhere in the first few weeks. None of that means anything has gone wrong — but it is considerably harder to sit through when it arrives unannounced.
Two pages are worth reading before you go in rather than after. Knee replacement recovery sets out the timeline week by week. Five things not to do straight after a knee replacement covers the mistakes that are easy to make in the first fortnight and genuinely costly.
If you have been reading about other people’s recoveries online, reading about knee replacement online is worth a look too — what you find there is real, but it is not a representative sample, and knowing that in advance helps.
And write your questions down. The consultation before surgery is the right place for the specific ones — about your knee, your work, your sport, whether kneeling matters for what you do, and what the plan is if something does not go as expected.
This page is general preparation advice. Your surgical team will give you instructions specific to your operation and your health, including what to do about your own medications. Where they differ from anything here, follow theirs.
If you have a knee replacement planned and something here raises a question, phone the rooms on (08) 6332 6365 or ask at your pre-operative appointment. Appointments can be made through the contact page.
Does exercise before a knee replacement actually help?+
The evidence is modest rather than dramatic, and it is honest to say so. What it supports is a faster early recovery — patients who go in with stronger quadriceps tend to get moving sooner and need less help in the first weeks. The two things preparation reliably buys are strength you would otherwise have to build from a lower base afterwards, and knowing what is coming, which makes the first fortnight considerably less frightening. Neither changes the final result at a year, and neither is a reason to delay surgery.
What exercises should I do before a knee replacement?+
Work aimed at the quadriceps, the hip muscles and the arms, plus daily work on getting the knee as straight as it will go. Straight leg raises, sit-to-stands from a firm chair, and standing hip work are the usual core. Arm strength matters more than people expect, because crutches are worked by the arms. All of it needs to stay within what the arthritic knee tolerates — the aim is to arrive stronger, not to arrive sore. A physiotherapist can set this out properly for your knee.
How far in advance should I start preparing for knee replacement surgery?+
Six weeks of consistent work is a reasonable target and enough to make a measurable difference to strength. Less is still worth doing. If surgery is closer than that, focus on the parts that do not need a training effect — organising the house, arranging help and physiotherapy, sorting out teeth and skin, and getting the practical arrangements settled.
Should I see a dentist before a knee replacement?+
If you have a known dental problem, or you are overdue for a check, it is worth dealing with beforehand. Bacteria from an untreated dental infection can travel in the bloodstream and settle on a new joint. It is a small precaution against an uncommon but serious problem, and it is much easier to address before surgery than after.
Do I need to lose weight before a knee replacement?+
It depends on your circumstances, and it is a conversation to have rather than a rule to apply. Weight influences both the operation and the life of the implant, but so does the fact that a painful knee makes losing weight considerably harder. Where weight is a significant factor it is raised directly and a realistic plan is discussed. It is not used as a barrier to be cleared before anyone will talk to you.
What should I organise at home before a knee replacement?+
Clear the trip hazards — loose rugs, trailing cords, cluttered hallways. Set up one comfortable chair that is firm and high enough to stand up from easily, with somewhere to prop the heel. Put what you use every day at waist height so nothing needs reaching or bending. Cook and freeze some meals. Arrange for someone to be around for the first week or so, and make sure you can get in your front door — steps and a walking aid need thinking about in advance.
Should I stop smoking before a knee replacement?+
Yes, and the earlier the better. Smoking impairs wound healing and raises the risk of both infection and anaesthetic complications. Stopping two weeks beforehand reduces that risk; stopping earlier reduces it further. Your GP can help with what is available, and it is one of the few things in the run-up to surgery that is entirely within your control.