Your new knee will continue to improve for as much as two years after your operation as the scar tissue heals and you exercise your muscles. You'll need to look after yourself and pay attention to any of the following problems:
Stiffness – Sometimes the knee can become very stiff in the weeks after the operation for no obvious reason. Try placing your foot on the first or second step of the stairs, hold on to the banister and lean into your knee. This should help to improve movement and flexibility in your knee. It’s very important to continue with the exercises you were working on in the hospital.
If the stiffness doesn’t improve after about six weeks your surgeon may need to move or manipulate your knee. This will be done under anaesthetic.
Pain – Pain caused by bruising from the operation is normal in the first two months, and you'll probably still need to take painkillers at six weeks to help you sleep through the night. You may still have some pain for as long as six months. If you still have pain after this, speak to your physiotherapist or GP.
Swelling – Swelling is a very common problem after a knee replacement, particularly affecting the ankle and foot, and may last for up to three months or so after the operation. The ankle swelling usually settles as your walking ability improves.
Swelling of the knee itself is also common over the first few months after surgery. Applying ice can be very helpful for a swollen joint, but make sure you protect your skin from direct contact with the ice pack. Ice can be applied for up to 20 minutes at a time. Raising your foot above hip height (on a footstool or similar) is another good way of reducing swelling, but make sure you get up and walk around for at least five minutes every hour to help reduce the risk of a blood clot.
Infection – You should speak to your GP or hospital if you notice any signs of infection, for example:
- breakdown of the wound with oozing/pus or sores
- increased pain
- redness and the affected area feeling warmer than usual or smelling unpleasant.
You should also look after your feet – see a doctor or podiatrist if you notice any problems such as ingrown toenails that could become infected.
Getting back to normal
It will be some weeks before you recover from your operation and start to feel the benefits of your new knee joint. Make sure you have no major commitments – including long-haul air travel – for the first six weeks after the operation.
Keeping up your exercises will make a big difference to your recovery time. You’ll probably need painkillers as the exercise can be painful at first. Gradually you’ll be able to build up the exercises to strengthen your muscles so that you can move more easily.
It's important to use crutches or walking sticks at first because the thigh muscles (quadriceps) will be weak after the operation, and falling could damage your new joint. Don't twist your knee as you turn around. Take several small steps instead.
After two weeks, or sooner if you’re confident, you can go down to one crutch and then a walking stick. After about six weeks, if your muscles feel strong and supportive, you can try walking without aids. This process may take less time if you’ve had a partial knee replacement or longer if you’ve had a more complex operation.
You should be able to walk outside within three weeks of having surgery but make sure you wear good supportive outdoor shoes. After three weeks, try to take longer strides so you can fully straighten (extend) your leg.
Going up and down stairs
When going up stairs put your unoperated leg onto the step first, then move your operated leg up. When going down stairs, put your operated leg down first, followed by your unoperated leg.
Sitting and kneeling
Don’t sit with your legs crossed for the first six weeks. You can try kneeling on a soft surface after three months when the scar tissue has healed enough. Kneeling may never be completely comfortable but should become easier as the scar tissue hardens.
You don't need to sleep in a special position after knee surgery. However, you shouldn't lie with a pillow under your knee. Although this may feel comfortable it can affect the muscles, making it difficult to straighten your knee.
You should be able to manage light household tasks like dusting or washing dishes. But avoid heavier jobs like vacuuming or changing the beds, or get help with them, for the first three months. Avoid standing for long periods as this could lead to your ankles swelling. If you’re ironing, sit down if possible and take care not to twist. Avoid reaching up or bending down for the first six weeks.
You’ll be able to drive after your joint replacement as long as you can safely control the vehicle and do an emergency stop. It’s important to check with your insurance company whether you’re covered during your recovery, and you need to be confident that you can control the vehicle in all circumstances.
You'll probably be able to drive again six weeks after a full knee replacement or about three weeks after a partial knee replacement. If you’ve had surgery on your left knee and you drive an automatic you should be able to drive earlier as long as you’re not taking strong painkillers.