There are many conditions which require a knee replacement. The most common is osteoarthritis. This means that the cartilage of the knee has worn out, resulting in the top of the shinbone (tibia) and the bottom of the thigh bone (femur) rubbing together. This is very painful and stops you from being able to move your knee as you once did.
What is a Total Knee Replacement (TKR)?
A TKR involves removing the end of the thigh bone, and the top of the shinbone, and replacing them with prostheses (artificial knee implants). The artificial knee is usually made of metal alloy and high-density plastic.
Before your operation, one of the surgical team will discuss the procedure with you and answer any other questions you may have. You will also be asked to sign a form, giving your consent to the operation.
The anaesthetist will visit you before your operation to discuss your anaesthetic options.
You will be told not to eat for approximately six hours and drink for two hours before your operation, depending on your anaesthetist's instructions. Failure to follow these instructions will result in your operation being delayed or even cancelled.
Our porters will take you to the operating theatre and a nurse will accompany you and hand you over to the care of the theatre team. The operation usually takes between one and one and a half hours. You may be away from the ward longer than this as you will be taken to the recovery area and cared for there until you are well enough to return to the ward.
After the operation, you will feel some pain and discomfort, which will be helped by medication.
You will be offered pain relief every few hours which may include a combination of regular pain relief such as paracetamol as well as stronger opioid-based painkillers.
It is a good idea to take these regularly in the first 48-72 hours. After this, you may be able to reduce the dose or frequency of some of these medicines.
You may have the following:
- A bulky bandage on your knee
- Small drainage tubes coming from your wound • A drip to replace lost fluids
- An oxygen mask
All will be removed as soon as possible after surgery.
Unless you have been told otherwise by a doctor or a physiotherapist, you can move as you feel comfortable after your total knee replacement. Prolonged convalescence increases the risk of blood clots and increases the risk of catching infections. Your goal will be to return to normal activities as soon as possible and the best place to do this is in the comfort of your own home. Please remember that you are not unwell: you will recover quicker from surgery by following our advice.
Today you will have your surgery. Once you have returned to your room and the anaesthetic has worn off, the physiotherapist or nursing staff will help you get out of bed and into a chair. Some patients may only get as far as sitting on the edge of the bed while others may progress further and walk a short distance. It all depends on how you feel.
With help from staff, you can begin to move your knee today. Please remember that the sooner you move, the easier it is to prevent complications after surgery.
To help you return to walking quickly, we advise that you take regular painkillers as well as additional medication such as laxatives to prevent constipation which is a common side effect of the strong painkillers. The nurse will give these to you.
You should try to be as independent as possible during the day, including getting dressed, sitting in the chair for meals and walking. You should wear some comfortable and loose clothes during the day. Pyjamas are for night time only!
You will be offered regular painkillers as prescribed. It is advisable to take pain relief when provided even if you are not in pain while lying in bed. Since you will be walking around the today, we expect you might experience some discomfort when you begin to move.
The physiotherapist will show you some exercises to help regain the movement in your new knee and to begin to strengthen the muscles in your thigh. It is important to work on both the bending and straightening of your knee. You should aim to complete the exercises as instructed at regular intervals throughout the day. Ice packs are available to assist with pain relief and to reduce swelling if required.
The physiotherapist will teach you to walk using a walking aid. You can turn around in either direction but you must prevent twisting or pivoting on your new knee. You should, therefore, lift your feet with each step and step around with small steps.
Once you can walk on your own, it is essential that you get up and walk regularly, even if this is only a short distance, to begin with. All walking is part of your rehabilitation. This includes any activities carried out with the physiotherapy and nursing staff.
Preparing for discharge
The team will discuss with you your possible discharge date and destination. The majority of patients are discharged directly home after four nights in the hospital.
Today you should be able to take a shower and get dressed. If you are having any doubts about how you will manage at home with personal care you should let a member of the ward staff know and you will be referred to an Occupational Therapist. Following an assessment, he/she will provide additional aids or equipment or recommendation for care on discharge.
The physiotherapist will continue to work with you to get the movement back in your knee. Most people are able to achieve a bend close to 90 degrees today but for others, this may take a little longer and depends on how much movement you had in your knee before surgery. Remember do not let your knee stay in one position for too long –gently move it every hour in addition to doing more focused exercises. If the knee swells too much it is time to rest with your legs up. You can ask the staff for an ice pack to help reduce the swelling. You need to reduce the swelling before you exercise. If the knee is too tight, exercising will be difficult.
You will also progress your walking. If you have been walking with a zimmer frame, aim to move onto crutches. Walking with the physiotherapists is not enough. You should also use the times when you have nothing to do to get up and walk. ‘Little and often’ is the best way forwards. The distance one walks vary from person to person. You will not injure your knee by walking but you need to monitor any swelling.
If you need to be able to go up and down the stairs when you go home, you might practise this with the physiotherapist today.
If you did not have an x-ray yesterday this should happen today.
Day 3 - Preparing for discharge
You will notice how quickly you are recovering from surgery. Some patients might be getting ready to go home today but everyone is individual. Today is about continuing to improving your knee range of movement, improving your confidence walking and ensuring you are functionally able to manage at home.
Getting ready for home
Continue to exercise your knee – remember you are aiming for a 90-degree bend and to be able to fully straighten the knee.
Continue to walk ‘Little and often’.
If you need to be able to walk up and down stairs you will practise these with a physiotherapist.
The Doctor should have written up medication in readiness for you to take home.
Day 4 - Your hospital stay should end today
You need to keep hold of this booklet as it has important information for you at home.
Continue to exercise your knee regularly at home to regain as much range of movement as possible.
Continue to walk ‘Little and often’.
If you need to be able to walk up and down stairs you will practise these with a physiotherapist
The Doctor will have written up medication in readiness for you to take home - everyone’s focus today will be on getting you ready to go home.
Going home and returning to activity
It is much better to get going as soon as comfortable after a hip replacement. Prolonged convalescence increases the risk of blood clots and increases the risk of catching infections. For these reasons, you will recover more quickly if you go home and get back to your previous lifestyle as soon as possible after your total hip replacement.
Unless you have been told otherwise, you can move as you feel comfortable after your surgery. You should avoid sudden or awkward movements. A few minutes spent planning will make it easier for you to manage most tasks independently once home.
Choose a firm, upright chair, preferably with arms that you find easy to stand up from. The ideal height of your chair depends on your height. If you do not have a suitable chair, see if you can borrow one, or use firm cushions to raise the height of the seat. Avoid low, soft sofas and armchairs since this might make it difficult for you to stand up.
To get out of a chair in the early stages when your knee is painful to push yourself up on the arms of the chair, taking most of your weight on your un-operated leg. Regain your balance and then get your crutches or sticks. Reverse the procedure to sit down.
Use the same method to get on and off the toilet.
A waterproof dressing will be organised by nursing staff after your surgery. In case you need assistance, you may want to make sure someone is in the house the first time you take a bath/shower.
Dress sitting on a chair or bed. Remember to dress your operative leg first, undress it last and wear good supportive shoes with low heels. Surgical stockings are required to be worn for six weeks following surgery. Plan ahead for someone to help you with these.
Stock up on food and ready-made meals before admission or use online shopping to get goods delivered to you at home. You can resume household activities as soon as you feel able to do so. You might need to enlist help from friends and family with tasks such as changing the bedding and vacuuming, as it will might be difficult to complete these tasks.
Sit for as many jobs as possible. A high stool is useful so that you can still reach the worktops. Place items that you use frequently at a height which is easy to reach. If you are unable to carry items, a kitchen trolley or a backpack may be helpful.
Make your home a suitable environment – clear clutter and remove loose rugs.
Getting in and out of a car
If possible, get into the car from a driveway or road, rather than upon a kerb.
The passenger seat should be as far back as possible and slightly reclined. With the passenger door open, back up to the car until you feel the seat at the back of your knees and gently lower yourself down.
Lift your bottom back towards the driver’s seat to give you plenty of room to swing your legs in.
To get out of the car, reverse the above procedure.
You may start driving 6 weeks after your surgery and when you can concentrate and control the car safely. Before you start driving, we recommend that you try the pedals in a stationary car and ensure you can do an emergency stop. It is also advised that you contact your insurance company to ask for their policies
Kneeling is not advisable for several months following your operation, after which you may kneel down as you feel able. You may find it more comfortable to kneel on a pad or cushion.
Many patients find they cannot kneel after their operation because it is too uncomfortable or because they are experiencing a strange sensation. You must take this into consideration if you kneel a lot due to work or hobbies.
Advice on exercise
When you get home, it is very important that you continue to do all the exercises taught to you while in hospital. This will ensure that your knee does not become stiff. You should continue to ensure that you are able to fully straighten the knee and bend it to at least 90 degrees. During the first 6 weeks, you will feel stronger and the exercises will become easier to do. Continue to take pain relief medication as needed to help you exercise.
Advice on managing knee swelling
It is normal to experience pain, bruising and swelling at the surgical site. Over the next 6 weeks, you should notice these symptoms improve. Swelling can continue for up to 12 months after surgery. Swelling can be relieved by resting with your feet up, using ice packs and exercising.
Advice on walking
Stay active and try to walk a little more each day. While your knee remains sore it is better to continue to use your walking aids as directed by the physiotherapists. It is better to walk normally with an aid than develop a poor walking pattern and limp by getting rid of your walking aid too early. Over time you will be able to progress and aim to walk unaided if you were doing this before surgery.
Advice on stairs
During your hospital stay, your physiotherapist will show you how to climb the stairs (if applicable).
Always use walking aids and if present a rail(s) or bannister (s) to support and assist you while going up or downstairs.
- Go up one step with your non-operated leg
- Take your operated leg up one step to join the other leg • Bring your stick(s)/crutch(es) up to the step
- Take your stick(s)/crutch(es) down one step
- Place your operated leg down one step beside your walking aid(s) • Bring your non-operated leg down one step to meet the other
Outpatient/follow up appointments
Before leaving the hospital you will be given an outpatient appointment for approximately six to eight weeks time.
After your operation, you should experience some pain relief, which should improve your ability to walk.
RISKS of a Knee Replacement
- All operations have risks
- A knee replacement is a major operation and will place the body under stress
- Any underlying illnesses may worsen due to the operation
Common Risks (2-5 people in every one hundred hip replacements)
- Pain. The knee will be sore after the operation but will usually improve after the first few months. However, a degree of ongoing pain or discomfort can occur and, in some cases, be permanent.
- Bleeding. There will be blood loss and a drain from the knee may be used to collect this after the operation. A blood transfusion is occasionally required.
- DVT (deep vein thrombosis) is a blood clot in a vein due to the surgery. It can cause leg swelling and pain. Stockings and blood thinning medication will reduce your risk. Starting to move your legs early is one of the best ways to prevent blood clots from forming.
- Knee stiffness can occur after the operation, especially if the knee was stiff before the surgery. Further manipulation of the joint is occasionally necessary. Working hard with the physiotherapists to push the range of motion in your new knee is the best way to prevent stiffness.
- Loosening and wear of the knee replacement. The implants are designed to last 10-20 years, but in some cases, they fail earlier and require revision surgery.
Less Common Risks (Less than one in every one hundred hip replacements)
- Infection. The operation is performed under sterile conditions and you will be given antibiotics at the time of the operation. Despite this infections may still occur. This requires a course of antibiotics. Rarely, surgery to wash out the knee replacement or revise the replacement is required.
Rare Risks (Much less than one in every one hundred hip replacements)
- PE (pulmonary embolism) is when a blood clot moves to the lungs and affects your breathing. This can be fatal.
- Major nerve damage. It is normal to have a numb area around the scar. Larger nerves can also be damaged leading to temporary or permanent weakness (footdrop) or altered sensation in the lower leg.
- Bone damage. If a bone is broken or weakened during the insertion of the hip replacement further metalwork may be required to stabilise it, either at the time of surgery or at a later operation.
- Blood vessel damage. The vessels around the hip may be damaged which would require further vascular surgery.
- Death. This very rare complication may occur after any major operation.
REPORT SEVERE PAIN, MASSIVE SWELLING, EXCESSIVE NUMBNESS OR PINS AND NEEDLES.