What is a joint replacement?
It is when all or part of a diseased joint is surgically removed and replaced with an artificial, man-made joint. Joint replacements are most often done on the hips and knees, with approximately 40,000 hip replacement and 17,000 knee replacements being performed each year in the UK. However, the elbows, shoulders, wrists and ankles may also be replaced. Women are twice as likely as men to need a hip replacement and most people who have a replacement joint are over the age of 65 – surgeons are reluctant to replace joints in people under the age of 55 because of the increased risk of the joint becoming loose or worn within the person’s lifetime, which would necessitate a second operation.
Why do some joints need to be replaced?
Joints usually need to be replaced when movement becomes extremely limited and painful, which is often the result of advanced osteoarthritis or rheumatoid arthritis. Osteoarthritis (arthritis primarily caused by wear and tear) usually affects the weight-bearing joints (hip, knee), while rheumatoid arthritis (arthritis primarily caused by localised inflammation) can affect any, or all, the joints in the body. About 15% of all joint operations are second operations (known as revisions), usually because of loosening of the joint, although a few are done because of infection.
What can I expect to happen?
When you and your doctor believe that the benefits of having a replacement joint outweigh the demands of having a major operation, your doctor will refer you to an orthopaedic consultant. Your consultant will probably give you a thorough examination to make sure you are in good general health, including checking whether you are diabetic, have heart disease, have suffered from thrombosis (deep vein clot), and how well your kidneys are functioning (all of which can impact on a successful recovery). You are also likely to be referred for an X-ray if you haven’t had one very recently. If you have any infections, however minor, then your consultant will want to treat these before you have the operation because of the risk of the wound becoming infected.
The operation itself usually lasts about two hours. You will usually be given a general anaesthetic, which means you will be asleep during the operation, although sometimes a spinal (known as an epidural) anaesthetic is given, which means you will be conscious, but unable to feel pain. Most people stay in hospital for about 10-14 days, and will need to stay in bed for the first one or two days. After this you will be able to get up, and most people are able to walk with sticks after about 14 days. Some pain is normal following a joint replacement operation (it is a major operation remember), but this should not continue for months afterwards – contact your doctor if the pain does not start to subside gradually or if it actually becomes worse.
What else should I be aware of?
The vast majority of joint replacements are trouble free, with over 90% having no problems following the replacement and over 75% of patients being free of pain 10 years afterwards. As with any operation, however, there can occasionally be problems, including:
* Infections – about 2-3% of people who have a joint replacement will have problems with the wound becoming infected. The likelihood of this happening increases if you are diabetic, have rheumatoid arthritis, are prone to recurrent infections (such as recurrent bladder infections), have any other problems with your immune system (such as cancer), or if you have any infections, however minor, before the operation.
* Joints dislocation – about 3% of joint replacements dislocate, usually within the first couple of months. It is usually the result of the person involved trying to do too much too soon, as it takes a while for the joint to stabilise.
* About 10% of all patients will need a second operation (known as a revision) and the vast majority of these are for joint loosening, which is when the cemented union between the joint and the bone begins to work loose. It becomes more common the longer the joint is in place, so the younger the person is at the time of the initial replacement, the more likely it is that problems will occur. However, in recent years, joints that are cement-free have been developed and it is hoped that this will help reduce problems with loosening.
* More than one joint might be affected – so you may need more than one joint replaced. Sometimes a pair (both hips, for example) can be done together, but this is rare.
What can I do to help myself?
* Tell the doctor or consultant if you have an infection (however minor) just before your operation – any bacterial infection, including an infected nail, a boil, a septic cut, etc should be treated before you have the operation in order to reduce the chances of wound infection afterwards.
* Don’t try to do too much too soon – take it easy and don’t try and try to do too much for the first six months or so following your operation so that you give your new joint a chance to stabilise. You should take particular care during the first six to ten weeks and, in the case of hip replacements, you should sleep on your back and avoid anything that might put a strain on your hip or cause it to dislocate, including sex, crossing your legs, physical exertion (including sports), and driving. Ask your doctor or consultant for guidance in the case of other joints.
* Do your exercises daily – you should continue doing any exercises that the physiotherapist showed you.
* Keep fit – but don’t over do it. After the first ten weeks or so, you should start to exercise little and often, choosing low-impact activities, such as swimming (you may need to avoid breast-stroke), aqua aerobics, and brisk walking, rather than high-impact activities such as running, squash, and aerobics. Anything that causes you to put the joint under sudden stress, such as ballroom dancing, may also need to be avoided – ask your doctor for guidance.
* Lose weight if you are overweight – being overweight accelerates any joint problems, including any loosening or degeneration of replacement weight-bearing joints.
* Be aware of any changes – while some pain is quite common immediately following a joint replacement operation, some patients have on-going or increased pain and stiffness in the months following a replacement. This can indicate an infection or other problem, and you should contact the doctor if this happens.