Why May I Benefit from a Knee Replacement?
There are several reasons why you may need a knee replacement. The most common is osteoarthritis; this simply means that the cartilage in your knee has worn out. This results in the bone ends losing their smooth surfaces and causing bone to grind against bone. This can cause pain and stiffness in the knee. Rheumatoid arthritis or previous injury to your knee can also cause your knee to become stiff and painful.
What is a Knee Replacement?
A knee replacement involves removing only the damaged surfaces of your knee (the end of your thigh bone, the femur, and the top of your shin bone, the tibia) and replacing them with metal and plastic pieces which fit together to mimic the natural movement of the knee. The kneecap may be left untouched or sometimes the under surface may be smoothed off allowing a plastic button to be fixed to the back of it. The components are usually held in place by bone cement.
There are different types of knee joint replacement. The most suitable type for you will depend on the extent of arthritis affecting the bones.
• A uni-compartmental knee replacement is a partial knee replacement and is suitable if only one part of your knee is affected by arthritis.
• If more than one part of your knee is affected by arthritis you will need a total knee replacement which covers the whole surface of the knee (Figure 2).
The aim of a knee replacement is to reduce the pain and stiffness in your knee and this should improve your ability to walk
What to Bring Into Hospital?
You should expect to be in hospital for 3-5 days so bring enough comfortable daytime clothing and nightwear. You should bring sensible footwear: flat shoes or slippers that are easy to get on and off. Slippers should preferably have support around the heel. Your feet often swell up a little after the operation so make sure if you buy new slippers that they are big enough. You may find it helpful to bring in a long handled shoe horn.
Before the Operation
You will come into hospital either the day before or on the morning of your operation. We will give you advice on when to stop eating however normally you will have nothing to eat from midnight the night before your operation.
Immediately After the Operation
We will transfer you from the recovery room back to the high care unit. You will spend one evening in the high care. Post-operative x-rays will be taken then. If possible the physiotherapist will start your mobilisaton once you have recovered from the anesthetic
Some patients having a knee replacement operation have mild pain and others have more pain. Everyone is different but you should expect to have some pain. The nursing staff should be informed when you start to feel pain so that they can help you. It is harder to get the pain under control if you wait too long.
The anesthetist and ward staff will discuss pain relief options with you
Recovering From Your Operation
At first you will be lying on your back and you may find moving around the bed awkward. Try bending your good leg up and push down through the bed with your foot and arms to lift your bottom off the bed. You will be encouraged you to be as independent as possible, whilst making sure of your safety. Help will be offered with washing and dressing etc. following your operation, however you will be encouraged to do as much as possible on your own. Your dressing will be checked and only changed if necessary.
We will encourage you to be as mobile as possible after your operation. Where possible the nursing staff or physiotherapists will aim to have you out of bed the same day as your operation. This helps you return to independence, and helps prevent complications after your operation.
One possible complication is a blood clot in the calf, known as a DVT (deep vein thrombosis). A DVT can move to the lungs, this is known as a pulmonary embolism (PE). We will give you medication and or other mechanical means such as foot pumps to help prevent blood clots. However moving and walking as soon as possible after the operation is one of the best ways of preventing this.
You will have a course of physiotherapy prior to your operation. This will allow you to mobilise faster after the procedure. The physiotherapist will visit you either the afternoon of your operation or the next morning. They will teach you exercise to increase the circulation in your legs and increase the movement and strength of your new knee. These are important because the muscles around your knee are often weak and tight. This is because the pain and stiffness of the arthritic knee stopped you from moving it normally. It will help you if you start these exercises straight away unless we tell you otherwise.
We aim to have you up walking on the same day as your operation or the next morning. After your operation the physiotherapist will continue with your exercises and practice walking. You will use a walking frame to walk initially and will progress onto walking sticks or elbow crutches as soon as you are ready. You will also practice going up and down stairs before going home. At present we aim to get people home within 3-5 days of their operation but this varies and you may get home sooner or later than this.
Information for when you go home
You will normally go home 3-5 days after your operation. You should arrange for family or friends to take you home by car.
For a while after you go home, your wound may appear red, warm to touch or the wound may feel itchy. You may have swelling which can affect your whole leg. You may also have a change in sensation around your wound. In most cases these are normal after your operation. If you notice a marked change and the area around your wound becomes much redder and is very hot and swollen, or if you develop any discharge from your wound it is important that you get this checked for signs of infection as soon as possible. If you are concerned please go to the emergency deparmtent immediately or contact us
It is important that you continue to take regular painkillers once you are home. Remember painkillers can make you constipated so please drink plenty of fluids and have fibre in your diet. Painkillers are important to control your pain to allow you to continue to do your exercises.
When you go home it is important that you have regular rest and raise your leg (higher than your hip if possible). You may also find that an ice pack on your knee now and again will help. If you notice that your operated leg is swelling please rest more between your exercises. This is not unusual.
Please note if your calf is hot, swollen and painful to touch then contact us urgently. If you suddenly become very breathless and do not normally suffer from breathing difficulties then you should contact us urgently.
Continue to do the exercises you were shown in hospital 2-4 times every day. Knee movement and the strength in your leg will gradually improve over time.
Try not to sit for long periods. Go for short walks regularly and keep using your walking aids. Build up your walking distance gradually from short distances around the house to getting out and about. After 6 weeks you can gradually start to wean yourself off the walking aids. If you start to use 1 stick use it on the opposite side from your new knee.
Most people find it extremely difficult to kneel on their operated knee and it is probably best to avoid this. However it is acceptable to kneel for short periods if need be. We would advise you to use a cushion to kneel on.
You should avoid driving for 6 weeks after your operation. This allows some healing to take place and the leg muscles to become stronger. Only return to driving when you are able to comfortably and safely change gear and carry out an emergency stop. Avoid any long journeys at this stage.
There is no universal agreement on this however I advise you to avoid short flights for 6 weeks after your operation and long flights for a minimum of 3 months. If you are flying remember to do some circulatory exercises and if possible get up and move around. At 6 months after your operation the risks associated with sitting for long periods will be back to what they were before the operation.
Return to activity and work
You should avoid high Impact sports such as jogging, skiing, squash and high impact aerobics.
You should avoid activities such as bowling, golf and dancing for 6 weeks. After this reintroduce such activities gradually.
Use how your knee feels as a guide. If something feels uncomfortable, stop and try again the following week.
Gentle exercise such as swimming can be helpful. You must however wait until your wound is completely healed and should avoid breaststroke for 6 weeks after your operation.
Returning to work depends on how physically demanding your job is. Your consultant will advise you about this.