What is Knee Replacement Surgery?
The most common type of arthritis is osteoarthritis, where there
is gradual wear and tear of a joint. Arthritis eventually
wears away the normal cartilage covering the surface of the joint
and the bone underneath becomes damaged. Where this occurs in
the knee, your consultant may recommend a knee replacement.
The damaged and worn surfaces of the knee joint are carefully
removed and resurfaced with a Cobalt/Chrome metal joint that is
sized to fit. High density polyethylene (a type of plastic)
sits between the metal surfaces and acts as a bearing
surface. The back of the kneecap is also usually resurfaced
with the same material
Knee replacements usually last at least ten to fifteen years and
will return you to normal movement and activity levels with less
pain.
What does this involve?
Knee Replacement surgery is carried out in hospital under
general anaesthetic although most people also have a spinal
anaesthetic to make the legs completely painless for a few
hours. You would normally be admitted the evening before the
operation if your operation is in the morning or early on the day
if your operation is scheduled for the afternoon or the
evening. This allows you time to settle in and be
prepared.
You will not be able to eat for eight hours prior to surgery
although you will be able to drink small amounts of water up to
four hours before.
The operation itself takes up to 90 minutes and your
Surgeon will make a 15 to 30 cm cut down the front of your
knew. The kneecap is moved to one side so that the joint can
be reached. Once the joint has been replaced the incision is
closed with stitches or clips. An acrylic cement is usually
used to bond the new joint directly onto your bones.
Afterwards your knee will be tightly bandaged to help minimise
swelling and fine drainage tubes may also be left in for up to 48
hours.
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When will I recover?
You are likely to stay in hospital for one to four days after
the operation and your physiotherapists will give you exercises
that help you walk the day after the operation. You will
gradually progress from using crutches to using walking sticks and
you will be allowed to go home once you are fully weight bearing
and can manage stairs and to care for yourself.
The knee dressing can be peeled off easily ten days after the
surgery and, as the stitches are internal, they do not need to be
removed. You will be given a cold compress or 'Cryocuff'
along with instructions on how to cool your knee, which is
important and aids recovery. You will see your Consultant
once again six weeks after your operation to review your
progress.
Knee replacement is a major operation and recovery takes place
over 6-12 weeks. At six weeks, some patients will still be
using a walking stick but most are walking well and independently
at twelve weeks although you may not see the full benefit of
surgery for up to a year.
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What risks should I know about?
Knee Replacement surgery is a very successful operation but
there are some potential complications you should be aware
of. These only affect less than 4% of patients.
- Infection can occur although our theatres have ultra-clean air
operating conditions keeping infection rates at 1-2%.
- Blood clots are possible in any major joint replacement surgery
but again are in the 1-4% category and have well established
treatments including aspirin.
- A small patch of numb skin can be present on the outer part of
the knee near the kneecap, this will improve over time
- The knee will have some stiffness after the operation although
we are aiming for 0-125 degs of movement once things have settled
down.
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Circle care
Knee surgery is carried out in our specialist Knee Unit at
CircleBath where specialist knee surgeons have created a centre of
excellence. You can be sure of state of the art facilities
and the best possible care to get you back on your feet as soon as
possible.
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