Knee Replacement

About your operation

A total knee joint replacement is an operation designed to replace a damaged or diseased knee joint. Your knee joint is a complex hinge joint. It bends and straightens.

A knee replacement resurfaces the end of the femur (thigh bone) with a metal component, and the top of the tibia (shin bone) with a metal and plastic component. The under-surface of the kneecap may be resurfaced with a plastic component.

A uni-compartmental knee replacement is when only half of the knee is resurfaced.

The aim of your operation is to relieve pain, decrease stiffness or deformity, and therefore help to improve your independence and quality of life.

Complications

As with all operations there is the risk of complications. Your team will discuss possible complications with you throughout the whole process.

There are surgical issues that will be discussed with you, but which may not affect you. These include:

• Altered skin sensation in your leg
• Damage to arteries and nerves in your leg
• Bone fracture during or after the operation
• Swelling
• Infection
• Blood clot in your legs or lungs.

Your team will also discuss possible anaesthetic issues with you.
Common issues include:

• Sore throat
• Nausea
• Vomiting
• Itching.

Rare anaesthetic issues include:

• Infection
• Bleeding and nerve problems with any local anaesthetic technique
• Allergy to medications
• Heart, breathing or blood transfusion problems
• Stroke.

When you return home, keep an eye out for these following signs and symptoms:

• Chest pain
• Shortness of breath
• Coughing up blood
• Calf pain or swelling
• Fever or chills
• High temperature
• Any unusual discharge or bad smell from the dressing.

If you are concerned about any of these signs, see your family doctor immediately. In an emergency, dial 111.

Preparing for your operation

You should remain as fit and active as possible. There are some exercises you can do before your operation - you can watch these in the next section.

It is a good idea to visit your dentist before your operation. Loose teeth, cavities or poor mouth hygiene can lead to infections in the area of the operation.

Skin problems like eczema, psoriasis and rashes, along with any other open wounds or scratches, can also cause infection. It is important that you tell your clinical team about any of these as soon as possible.

The same applies to your toenails and feet - if they are in poor condition please see a podiatrist or your family doctor before your operation.

Please take care especially with pets and when gardening as cuts and scratches may result in your operation being postponed.

Where possible try to avoid colds and other infections as again these may delay your operation.

If you smoke, now is the time to think about stopping before your operation and staying smokefree during your recovery. Ideally you should stop smoking about 8 weeks before your operation. This greatly reduces your risk of developing complications. If you continue to smoke, you have a higher chance of getting a wound infection and bone healing will take longer or bones may not heal at all. You also increase your risk of developing a chest infection and are more likely to have a heart attack or stroke during or after your operation. Ask your local Health Board or your family doctor for the contact details of your local stop smoking services to receive free and confidential advice as well as subsidised Nicotine Replacement therapy. Remember, the longer you are smokefree before your operation, the better the result. Even if you’ve tried giving up before, it’s worth having another go.

Alcohol may also affect your recovery so it's important to stop drinking alcohol or at least reduce your intake at least 1 week before your operation.

It is important to eat well before your operation. Have regular meals and if you find yourself losing weight, please discuss this with your nurse when you go to hospital.

A common complaint following surgery is constipation. You can reduce this by eating plenty of fruit and vegetables and by drinking lots of water before coming into hospital and while you're in hospital.

Remember, all these things are very important in helping to make your recovery as fast as possible.

Before your operation - Exercises

These exercises are recommended to be completed 3 times a day prior to surgery.

Through range quadriceps: Sit in a chair so your thigh is well supported. Pull your toes back toward you and straighten your knee. Slowly lower. Repeat 10 times.

Seated knee flexion: While sitting in a chair, pull your foot back underneath the chair as far as you can. Using a plastic bag under your foot will help it slide further. Repeat 10 times.

Reverse knee bends: While sitting in a chair, slide your feet underneath you as far as possible. Keeping your feet fixed, shift your bottom forward on the seat. Slowly slide back into the chair. Repeat 10 times.

Using a static exercise bike is highly recommended to increase the range of movement in your knee. Initially start with the seat high. It's all right if you cannot complete a full rotation, but if you can, then progress by lowering the seat.

Before your operation - Home preparation

You are likely to find household tasks difficult after your operation. Ask family or friends if they can help you with chores such as cleaning bathrooms and floors, vacuuming, changing bed linen and mowing the lawn.

Now is the time to make changes around the house to make it safer for when you return home. Have a look around and think about how you would manage things like cooking, washing, bathing and stairs. Check for things you may trip over such as mats, carpets and even pets.

Carrying hot food and drinks will be quite tricky so think about ways to make preparation and carrying easier. A thermos is excellent for hot drinks.

It is generally unsafe to get in and out of a bath for at least 6 weeks after your operation. It is best to use a shower with a non-slip mat. A shower chair is a good alternative.

You may not be able to drive for up to 6 weeks after your operation. Getting in and out of a car may also be difficult.

Laundry can also be difficult after your operation. Using a clotheshorse is recommended. An "Easy Reacher" can also help with getting clothes out of the washing machine.

If you are living on your own, it would be useful if you or a family member could prepare meals and freeze them so you have some meals ready to eat when you return home.

Before your operation - General information

Unless otherwise advised, you should continue taking your medications right up to the day of your operation.

Note that some herbal remedies are not recommended before your operation. If there are any medications that you need to stop before your operation, your anaesthetist will discuss these with you and give you instructions.
It is important to contact the hospital if you become unwell before your operation.

Also, if your medications change; if you are admitted to hospital after being given your date for surgery; or if you've had any significant changes to your personal circumstances, please report these to your clinical team.

The day before your operation

Please eat and drink normally the day before your operation, unless advised otherwise. You can eat up to 6 hours before your operation and you can drink clear fluids up to 2 hours before your operation. Clear fluids are fluids that you can see through, without fruit pulp or milk. Avoid carbonated or fizzy drinks, and drinks that contain caffeine, including tea and coffee.

Remember to follow the instructions from your anaesthetist about which medications you can take on the day of your operation. This is very important as your operation can be cancelled if you do not follow this.

You may receive a call from the hospital pharmacist to discuss what medications you take and if you have any allergies. Although you will be supplied with medicines from the hospital stock during your stay, you may be asked to bring in your own medication.

When packing your bag for your hospital stay, the following items are recommended:

• All the medications that you are currently taking in their original packaging with the pharmacy labels attached
• A medication card if you have one
• Personal toiletries
• Nightwear
• Loose-fitting day clothes (remember staff will need to attend to your wound)
• Appropriate footwear (remember your feet tend to swell after surgery and you will not be able to bend down to tie shoelaces)
• Your patient education booklet(s).

Please leave your valuables and jewellery at home.

The day of your operation

You're welcome to bring a relative or friend with you on the day of your operation.

Once checked in at reception, you'll be given paperwork to fill out and you'll be asked to change into a theatre gown. Depending on where you are placed on the operating list there may be some waiting time. Staff will advise you on where your personal belongings will be stored.

Before going into theatre, you will see your anaesthetist and surgeon. You may like to ask them questions. It's a good idea to have your questions written down as you may not remember them on the day.

Your surgeon or their registrar will review and confirm your operation details and will mark the operation area with a marker pen.

Your anaesthetist will also explain the anaesthetic options available to you.

You will then be taken into theatre and your anaesthetist and anaesthetic technician will explain to you what will happen.

Your operation will take between 1 to 2 hours.

At the end of your operation you will be taken to the recovery room to be monitored. Then, you will be transferred to the ward.

Following any major operation you'll experience some pain or discomfort but your team will do their best to manage this. Some patients feel sick after an operation - if you do, let staff know immediately.

Some patients also find it difficult to pass urine after an operation. Your nurse will be closely monitoring you and may use a bladder scanner to see whether you need a urinary catheter. If one is needed it will usually be used only for a short while.

Anaesthesia

There are a number of options available for your anaesthetic. The one that will be best for you depends on many factors, mostly relating to your safety and pain relief after the operation.

Most people are sedated and will have either a spinal anaesthetic or a combined spinal-epidural anaesthetic. Nerve blocks can also be used in the leg or thigh. Some patients will have a general anaesthetic, where you are put to sleep during the operation.

You will be involved in deciding the best anaesthetic for you, but your anaesthetist will be there to guide you through this process.

After that you will need to sign a consent form for your anaesthetic and also for a blood transfusion. Transfusion is rare but your team needs to know if you have any concerns or objections to this before they start as it can affect the type of operation or anaesthetic used.

During your operation

During the operation you'll be connected to monitors so the clinical team can keep an eye on your blood pressure, pulse, breathing and oxygen levels. You'll also have an intravenous drip inserted into your arm for medication and fluids.

Should you choose spinal or epidural anaesthetics, these are administered while you're sitting up or lying on your side. Your back will be washed with an antiseptic and then some local anaesthetic medicine will be injected to numb the skin before the spinal or epidural anaesthetic is administered.

After this, you'll lie down on the bed. If a urinary catheter is needed, it will be inserted after the anaesthetic is started.

It is likely that you will have sedation for the procedure and this may start at the same time as the epidural or spinal anaesthetic.

For some people a general anaesthetic is the best option and this is administered soon after you enter the operating area.

If you choose to have a nerve block to numb the nerves, you will be given some relaxing medicine and a local anaesthetic injection to relieve you of any possible pain before the nerve block injection is given.

After your operation

After your operation, you will be encouraged to get up and move as soon as it is practical and safe. Research shows that moving early reduces some complications of big operations and starts you on the road to a quicker recovery.

A nurse will talk to you about when you may be able to go home.

You will receive help with tasks such as washing, dressing and walking to the toilet, but the aim is for you to become as independent as possible, as soon as it is safe to do so.

You will be shown simple exercises that you can do in bed and you will be assisted to sit in a chair for all your meals. You will be assisted by staff to walk short distances with crutches or a walking frame once your anaesthetic has worn off and staff have assessed that you are safe to move.

With any major operation you'll experience some pain or discomfort but your team will do their best to manage this. Pain relief will be given regularly for some people, while others may only need it on an 'as required' basis.

Constipation is a common side effect after big operations. Drinking plenty of fluids, especially water, and moving around can help to prevent constipation but laxatives can be prescribed if it becomes a problem.

After your operation, your leg will swell. This is perfectly normal. The swelling should go down, but if you're lying on your bed, ensure your leg is raised above your heart. If you sit for periods of 45 to 60 minutes you'll notice swelling in your ankles and feet. It isn't dangerous and won't cause any damage but it will become uncomfortable, so it is best not to rest for this long. Walking around will help reduce the swelling.

By the time you leave hospital, you will be able to walk well, and be relatively comfortable taking tablets for pain.

Day 1 and Day 2 after your operation

You will continue to work towards your goal of going home early or on time.

Your blood count will be checked to see if you need a blood transfusion. Most patients don’t need blood replacement, however if you do you will need to consent to this.

An x-ray will be taken to check the position of your new joint.

Getting up and about as soon as possible after your operation is an important part of recovery. Your pain needs to be well controlled with movement and not just resting. Ask your nurse for pain medication if required.

You will be shown exercises that will help you regain strength and movement. You will sit in a chair for all your meals and be assisted to walk with crutches or a walking frame. Nursing staff will support you with washing and dressing as needed.

An occupational therapist will assess you to see what equipment you may need at home. Any equipment needed will be supplied by the hospital for you to take home.

Going home

Before you go home, staff will make sure your wound is clean and dry and that your temperature is normal.
You'll need to be able to walk with crutches or a frame and go safely up and down stairs if required. You will also need to be able to get on and off the bed on your own.

It’s important you take pain relief to help you walk and move as well as possible. This may include regular paracetamol, anti-inflammatories or even stronger medications. Your anaesthetist and ward nursing staff will advise you on the best pain management before you go home.

When you get home, you will receive a follow-up appointment to see your surgeon. Your wound also needs to be checked and any stitches or clips will need to be removed as instructed.

It is really important to drink plenty of fluids, especially water, and eat often. Even if you don't feel like it, try to have something small 3 to 5 times a day and remember your exercises for at least 12 weeks. You'll benefit from doing them for up to 1 year following your operation.

After your operation - Exercises

You should continue these exercises 3 times a day for at least 12 weeks after your operation.

Through range quadriceps: Sit in a chair so your thigh is well supported. Pull your toes back toward you and straighten your knee. Slowly lower. Repeat 10 times.

Seated knee flexion: While sitting in a chair, pull your foot back underneath the chair as far as you can. Note that using a plastic bag under your foot will help it slide further. Repeat 10 times.

Reverse knee bends: While sitting in a chair, slide your feet underneath you as far as possible. Keeping your feet fixed, shift your bottom forward on the seat. Slowly slide back into the chair. Repeat 10 times.

Using a static exercise bike is highly recommended to increase the range of movement in your knee. Initially start with the seat high. It's all right if you cannot complete a full rotation, but if you can, then progress by lowering the seat.

Reference:   Ministry of Health (MOH) - 2015