Top 5 Mistakes to Avoid After Knee Replacement

The most common mistakes after knee replacement are skipping or overdoing exercises, letting pain and swelling build, doing too much or too little, ignoring warning signs, and letting the knee stay bent. Avoiding them can help your recovery. Your surgeon and physiotherapist will give advice for your own situation, so follow it.

Recovering from a knee replacement takes time. It is normal to feel unsure about what you should and shouldn’t do.

This guide is for people thinking about surgery, and for relatives helping someone through it. It gives general information only. Your own surgeon and physiotherapist will tell you what is right for you.

If you are still deciding, our guide to what patients regret about knee replacement is also worth a read.

Mistake 1: Skipping exercises, or overdoing them

Exercises are a central part of recovery. They help your knee bend and straighten, rebuild strength in the leg, and get you back to everyday tasks.

Many people are told to do their exercises several times a day in the early weeks. Skipping them can leave the knee stiff and the leg weak. Doing far more than your plan suggests can leave it sore and swollen.

How long should you do exercises after knee replacement? It varies. Many people follow a structured plan for several months, and some are encouraged to keep up a gentler routine after that. Your physiotherapist will tell you what suits you.

Some discomfort during exercise is common. Sharp or worsening pain is different. Pushing through it isn’t the answer. Stop, and ask your physiotherapist or surgical team for advice.

Mistake 2: Not keeping on top of pain and swelling

Pain relief isn’t just about comfort. When pain is controlled, you can do your exercises properly and keep moving.

Many people are told to take pain relief as prescribed, rather than waiting until the pain is bad. Your team will explain what to take and when.

Swelling is very common after knee replacement and can last for weeks. Resting, raising the leg and using cold packs may help, but only as your team advises. Cold packs should not go directly on the skin.

If your pain is getting worse rather than easing, tell your surgical team.

Mistake 3: Doing too much too soon, or too little

Recovery works best at a steady pace.

Doing too much too soon, such as long walks, lots of stairs or a busy day on your feet, can bring more swelling, heat and pain the next day. If that happens, it is a sign to ease off.

Doing too little has its own risks. Long spells of sitting or lying can lead to stiffness and weakness, and can slow your progress.

A sensible approach is short, regular walks and your exercises through the day, with rests in between. Build up gradually. Your physiotherapist can help you find the right balance.

Mistake 4: Ignoring warning signs

Most recoveries are straightforward. But it helps to know what to look out for, so you can act early.

Possible signs of infection

The wound becomes more red, hot, swollen or painful
The wound leaks fluid or starts to open
You have a high temperature or feel feverish or unwell

Possible signs of a blood clot

Pain, swelling, warmth or redness in your calf
A calf that feels tender or tight, usually on one side

If you notice any of these, contact your surgical team, your GP or NHS 111 for advice.

Call 999 if you have chest pain, sudden breathlessness, or cough up blood. These can be signs of a clot in the lung and need emergency care.

For more on symptoms to take seriously, read our joint pain red flags blog.

Mistake 5: Letting the knee stay bent

Getting your knee fully straight matters. It helps you stand and walk more normally, and it makes later recovery easier.

One common habit is putting a pillow under the knee because it feels comfortable. Unless you have been told to, avoid this. It can encourage the knee to stay bent.

Lying down

Many people are advised to lie on their back with the leg resting straight, supported along its length. Your physiotherapist can show you what is right for you.

Sitting

Many people ask about the best sitting position after knee replacement. Most are advised to use a firm, supportive chair with arms, which makes getting up easier. Sit with your feet flat on the floor, and avoid very low sofas. If you are told to raise your leg, support the whole leg, not just under the knee.

Try not to sit for long stretches. Stand up and move around regularly.

The worst days after knee replacement

Many people find that days two to three, and the first week at home, are the hardest. Swelling often builds during this time, and tiredness and poor sleep can make everything feel harder.

This is a very common experience, and it usually settles. It doesn’t mean something has gone wrong.

Things that many people find helpful:

Taking pain relief as prescribed
Keeping to short, regular walks and your exercises
Resting between activities
Having a relative or friend nearby for the first few days
Setting up your home before surgery, with items within easy reach

If pain or swelling is getting worse, or you are worried, contact your surgical team.

Long term dos and don’ts

Many people ask about permanent restrictions after knee replacement. There are fewer than you might expect, but your surgeon will give advice that fits your knee and your health. What follows is what most surgeons advise.

If your knee still aches long after surgery, read why a knee can hurt years after surgery.

Kneeling. Many people can kneel, though it may feel uncomfortable or odd. Some find a cushion helps. Ask your surgeon when and whether it is suitable for you.

High impact sport. Sports with a lot of jumping, twisting or heavy impact are generally discouraged, as they put more stress on the joint.

Running. Can you run after knee replacement? Most surgeons advise against regular running, because of the repeated impact. Some may take a different view for individual patients. Talk to your own surgeon.

Walking, swimming and cycling. These are widely encouraged. They keep the joint moving and the muscles strong, with less impact.

Golf. Many people return to golf, often with some adjustments. Your surgeon or physiotherapist can advise on when to start.

How far should you be walking at 6 weeks?

There is no single right distance. Recovery varies from person to person.

By around 6 weeks, many people are walking more comfortably and for longer, often with fewer aids than at the start. The aim is to build up gradually. Short walks several times a day are usually better than one long one.

Your physiotherapist will set goals that suit you. If you are unsure whether you are doing too much or too little, ask them.

Frequently asked questions

What is the worst day after knee replacement?

Many people find days two to three, and the first week at home, the hardest, as swelling builds. This is common and usually eases. Taking pain relief as prescribed and keeping gently active can help. Contact your team if you are worried.

How long should you do exercises after knee replacement?

This varies. Many people follow a structured exercise plan for several months, and some are encouraged to continue gentler exercises after that. Your physiotherapist will advise what is right for you.

Can I kneel after knee replacement?

Many people can, although it may feel uncomfortable. Some find a cushion helps. Check with your surgeon before trying it.

When can I drive after knee replacement?

The timing varies. It depends on which knee was replaced, whether your car is automatic, and how confident and in control you feel. Your surgeon will advise. Read our driving after a hip or knee replacement blog for more.

Can you run after knee replacement?

Most surgeons advise against regular running because of the repeated impact on the joint. Some may take a different view for individual patients. Ask your own surgeon.

How far should I be walking 6 weeks after knee replacement?

There is no fixed distance. Many people are walking further and more comfortably by this stage, building up gradually with short, regular walks. Your physiotherapist will guide you.

Thinking about knee replacement?

Everyone’s recovery is different. This article is general information and isn’t a substitute for advice from your surgeon or physiotherapist.

If you would like to talk through your options, book a free consultation with our team. If cost is on your mind, read our knee replacement cost guide or try our price check.

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