Half or Partial Knee Replacement

The following information has been written in line with the Physiotherapy and Surgical teams at the James Paget University Hospital. If you have had your operation at another hospital, you should refer to the information and advice you were given as it may differ from the information below.

What is a half knee replacement?

A half or partial knee replacement is a major operation that involves replacing one half of your knee joint with an artificial joint, normally the inside half.

X-ray of a partial knee replacement with front and side view of the knee bones.

Why have I had a half knee replacement?

Every case is different, however, in a lot of cases people will choose to have their knee joint replaced because of osteoarthritis (for more information on osteoarthritis click here) that hasn’t improved with physiotherapy and/or has become increasingly difficult to live with.

What should I expect after having a half knee replacement?

This is a really important question and it is useful for you to know what is normal after having your knee replaced. We’ve broken the answer down into things that are found most commonly:

A half knee replacement is a big operation; it is very normal for your knee to be swollen afterwards. The swelling is part of the healing response and is supposed to be there. Interestingly, the swelling will often hang around for some time, maybe weeks into months. However, just because the swelling is still there, doesn’t mean there’s a problem, it is quite normal and to be expected.

As mentioned in the swelling section, a half knee replacement is a big operation and will be painful. The pain from your operation is linked to the scale of the surgery and is likely to be with you for some time, possibly weeks or months, but again, this doesn’t necessarily mean anything is going wrong as it is normal and to be expected.

It is very normal to find that your knee doesn’t move fully after your operation. Often, because it will be swollen and sore (see previous section) your knee will be difficult to bend and straighten. This will be most obvious just after your operation but should improve with time.

Most people who have had a half knee replacement will have been told by the hospital that they are allowed to take as much weight as they can through their new knee. It is very normal to find walking a bit of a challenge after having knee surgery and you may find that you need to use elbow crutches or a walking stick to help you in the early stages of your recovery.

You can find some useful videos on how to using elbow crutches/ walking sticks etc. here: Walking Aids

What can I do to help my knee recover?

Reassuringly, there are lots of things that you can do to help get your knee going and start your recovery.

Firstly, it is important to know what is normal, therefore, if you haven’t already, please read the ‘What should I expect after having a total knee replacement?’ section.

Getting your knee moving is key to getting a good result after a partial knee replacement and helping to reduce any swelling. You may or may not have been given some advice and exercises from the hospital where you had your operation. If you were given an exercise programme, then it would be advisable to start that as soon as you are able to. If you were not given an exercise programme, you will find some great exercises at the bottom of the page that would be useful to explore.

You may also find it useful to rest your foot on a stool or chair to help with the swelling.

As mentioned previously, a partial knee replacement is a painful operation. Some people will choose to manage this pain with pain relief, whilst some may choose to avoid medication. It is normal practice for you to have been discharged from hospital with pain relief, however, if you need pain relief and either don’t have any or what you have isn’t working, please speak with your GP or pharmacist.

Applying something cold to your knee may also be useful in helping with some of the pain (do remember to wrap your frozen peas in a towel before applying them to your skin to avoid cold burns).

Exercise is one of the most important things for getting your knee going. Exercise can mean a lot of things and generally walking, climbing stairs and getting in and out of the chair are really good for your new knee, but sometimes, we need to use focused exercises for the knee to really get the best out of it.

Most hospitals will have given you a programme of exercises to complete after your operation, however we have provided a selection of other exercises at the bottom of the page to explore if you would like to. It is really useful to know that your exercises will be tough and probably uncomfortable to begin with. It is worth trying to stick with them, as the movement will come, but you may have to work though some discomfort to get there.

I’ve been given a walking aid to help me walk, but I’m not sure how to use it.

No problem. Please click on the picture of the walking stick and you will be taken through to our Walking Aids page. Don’t forget to come back here for more useful information about your knee recovery.

A brown wooden walking stick with curved handle in an upright position.

Is there anything I should look out for?

After any operation, it is important for you to be aware of what is normal (see above) and perhaps, what is not. Below is a list of things that should be raised to your doctor, surgeon or practice nurse if you experience them after your surgery. If you have previously had a Deep Vein Thrombosis (DVT), you should familiarise yourself with the list and monitor yourself for any issues.

If your wound edge becomes red, oozy and/or painful, please contact the ward that you were admitted to for your surgery. Please do not contact your GP. You will be asked to come into the hospital for a review by your consultant or their team.

Generally feeling unwell and/or a temperature following surgery

Red, painful, swollen calf or calves

Entire leg considerably swollen

Painful groin or back of your thigh

Inability to move your foot with or without numbness below the knee

Sudden change in breathing i.e. finding yourself breathless; coughing up blood or a new pain in your chest – this could indicate a medical emergency and you should call 999 or go to A&E)

What does a good result look like after a half knee replacement?

As you would expect, everyone is very different, but after a half knee replacement it is hoped that the pain you felt before your operation would have improved, and your ability to use the new knee would also have progressed i.e. being able to walk easier or get out of the chair with less effort.

There is often a large variation in how much movement comes back after a new knee, but if it is less painful and you can do more with it, it still means you’ve got yourself a good result.

How can I get the best out of my new knee?

Use it and enjoy it! Recovery after a half knee replacement can sometimes be a bumpy journey and will take time. Often, you may not really get a good idea of just how good the result is until you are 12 months after the operation.

If you want to make sure you get the very best out of your new knee, getting or keeping yourself fit and strong will make sure that you, your body and your new knee are in the best shape to enjoy it. You will find a selection of strengthening exercises below that you may be interested in to really try to get your knee strong enough to do most of what you want it to do.

FAQ

Below are some common questions that are asked when talking about half or partial knee replacements that haven’t been covered in the information above.

Q: Is there anything I shouldn’t do with my new knee?

A: No, not really. As long as you are sensible and listen to your body, you should be able to do anything that you want to with your new knee.

Q: As I’ve had half a new knee, does it mean I’m going to have to have a full knee replacement eventually?

A: No. Nothing is for certain and a lot of people can improve their knee to the point that they don’t have to consider additional surgery. Having to have a total knee replacement is not inevitable and you are the person who can influence that. Increasing your strength, being fitter, being closer to your ideal body weight and eating and sleeping well are all important things in terms of making your body, including your new knee, work better. Unfortunately, there are some people who do require additional surgery, but if you work hard on the things mentioned in this answer, you should hopefully reduce your chances of needing any.

Q: My knee looks different, should it be?

A: It is really not unusual to find that your knee looks different after the surgery. It will be swollen or you may have lost some muscle bulk in your legs before the operation, both of which will make your knee look different.

Q: My friend had a knee replacement and they were playing golf after a week. Why’s mine taking so long?

A: We are all different. It is often not useful to compare yourself to others, even if you’ve had the same operation. How difficult your knee was before the operation, your strength and how well your pain is controlled are just a few things that will vary from person to person. Recovery from a major operation takes time and it is best to think of this in terms of months rather than weeks.

Q: I’ve had my other knee partially replaced and it was much easier than this one, why’s that?

A: As explained in the previous question, we are all different and so are your knees. Even though having a knee replaced is technically the same operation, given that it is done on a different knee means that it’s not exactly the same, therefore it is unlikely the result will be exactly the same. Things like your age, strength, fitness and general health all change over time and will play a role in influencing how you get on after your operation, including if it’s your second one.

Q: When can I drive?

A: Generally it is recommended that you can return to driving six weeks after a left half knee replacement or allow eight weeks after a right total knee replacement due to the power required to brake. However, it is each individual’s responsibility to ensure they are fit to drive. You should ensure you can confidently and without any hesitation, perform an emergency stop before even considering driving on public roads.

It is always recommended to contact your insurance company one month before you return to driving to ensure your insurance is valid. This advice is the same if you drive an automatic car.

Q: When am I going to be able to walk ‘normally’?

A: Firstly, there is no such thing as a normal walking pattern, only what is normal for you. It often takes some time to get the right amount of movement and confidence to walk as normally as you hope to. Make sure you don’t rush things and continue to use a stick (if you have been issued with one) or crutches to make sure your walking quality is good before discarding them. Quality beats quantity!

Q: I’ve been told I can’t kneel on my new knee. Is that correct?

A: Technically, you are safe to kneel on your new knee but most people don’t have the required amount of movement to kneel comfortably, therefore they choose not to.

Q: My new knee clicks a bit. Is that normal?

A: Yes it is. Your new knee would have been put in place extremely firmly and it is incredibly rare for it to loosen. Occasional clicks and cracks are quite normal for joints, including newly replaced ones.