Knee Replacement / Knee Arthroplasty
Knee replacement or knee arthroplasty is the orthopaedic operation in which a diseased, worn or injured knee joint is replaced by an artificial joint. Knee replacements are now a routine operation, most commonly performed due to knee arthritis. It is an established, generally accepted medical intervention with predictable results from skilled orthopaedic surgeons.
This video shows the components which are inserted during a knee replacement, using a Scorpio knee.
The National Joint Registry, which collects statistics on all the joint replacements performed in Britain, shows that in 2010 in England and Wales there were over 56,000 knee replacements performed in the NHS and over 24,000 in independent hospitals with the vast majority of people being over sixty-five years old and somewhat over half of these being female.
Two main forms of replacement knee are performed: a whole or total knee replacement if the joint damage is widespread and a partial knee replacement if the joint damage is confined to one side of another of the joint.
As with hip replacement, knee replacements have a limited life span but can last from 15 to 20 years if they are well looked after and not put under undue physical stresses and strains. Revision knee replacement, where the surgery is done again for a problem or due to the joint reaching the end of its life, is a longer and more complex surgical matter than initial replacement and in general people are less pleased with their new knee each time it is redone.
Reasons for Having a Knee Replacement
Knee replacement is a major operation with all the risks and complications which go with such knee surgery. You may feel you need a knee replacement if you have these difficulties:
The knee is a large hinge joint and is made up of two joints overall. The much larger joint is the true knee joint between the rounded bottom end of the thigh bone and the flattened top of the shin bone, the smaller one being between the rounded bottom end of the thigh bone again and the back of the kneecap.
A firm, slippery and low friction material called articular cartilage or joint cartilage covers the surfaces of the joint and along with the fluid secreted by the lining membrane allows the easy movement of a joint even when it is loaded.
As the cartilage becomes worn or damaged the free and easy movement is lost and in severe cases the underlying bone is exposed and grates against the other side of the joint, causing pain and disability. Osteoarthritis is the commonest cause of this problem and the most common reason for performing knee replacement.
The components which make up the knee prosthesis are made up of a specialised stainless steel and a high density polyethylene. See the parts which make up an artificial knee joint here. Partial knee replacement may be used to replace just one of the sides of the joint, called a compartment, if the arthritis is confined to that side only. Knee replacement cost is high and partial replacement can reduce the costs by around £1700 or more
Knee Replacement Procedure
If you are planning on having a total knee replacement surgery you can read a short description of the knee replacement operation here. Depending on the type of clinical problem the orthopaedic surgeon finds, he or she can choose from various types of knee replacement surgery, with the main decision being between total knee replacement which replaces the entire articulating surface of the knee joint and kneecap and unicompartmental knee arthroplasty (partial knee replacement).
Knee Surgery Rehab
Unlike hip replacement, knee replacement demands a lot in terms of effort and you have to put up with more pain and swelling, do far more exercising for far longer and it may take three months or so for the knee to settle down. This means that it is important to prepare for knee replacement surgery, for instance by seeing the physiotherapist so your knee can be assessed and advice and exercises given. Find out what rehabilitation and knee replacement exercises you need to do.
After Knee Replacement
Towards the end of your hospital stay and afterwards read what should you expect on discharge.
A joint replacement is for life, not just for the short time you are with us. How you are monitored during the years ahead is vital and you can read here that kind of follow up you should expect. Knee replacement complications are common but most are minor and easily treated and ideally you should be able to forget about your new joint in daily life, but it is not like the original joint. You need to take some precautions for a sensible long life of coexistence with your joint. Read how to look after your new joint here.
Knee Replacement Complications
Due to the complexity of the operation and the necessity for you to participate fully in your operation and the following rehab with the physiotherapist it is very useful to have good knee replacement surgery information. This way you can review the knee replacement surgery risks and knee replacement complications and will benefit from useful media such as a partial knee replacement surgery video. There is a lot of information to take in about all aspects of the operation and recovery and there is useful additional information and a knee replacement animation at the NHS Choices website and Wikipedia has a page with many knee replacement links.
However, nothing will quite give you the understanding of the knee surgery you are about to have more than a knee replacement surgery video, especially the longer ones at half an hour or so. They have still been edited down to shorter times but include all the important steps which the surgeon goes through and show some of the reasons for the relatively long period of knee replacement recovery which follows this operation.
Signature Knee Replacement
Customised knee replacements are being developed to allow for the fact that many people, especially women and those with smaller or unusually shaped joints. Biomet has developed the Signature knee replacement system which uses MRI scanning to give a 3D image of the individual's knee to allow more precise operation planning. From the scan the system allows manufacture of alignment guides for the operation which can be used without being as invasive as normal alignment systems.
Hip replacement has similar issues to knee replacement, including the types of hip replacement available, hip replacement costs being less than knee replacement, the choice between hip replacement and hip resurfacing and the use in broken hip or fractured neck of femur.
Watching videos of the procedures is a very good way of understanding what's going on and enables patients to participate fully in their rehabilitation with the physiotherapist. Go to hip replacement video for more information.