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Unicondylar Knee Replacement Surgeon in Hertfordshire, Luton, Hatfield

Unicondylar knee replacement is a minimally invasive surgery in which only the damaged compartment of the knee is replaced with an implant. Mr Tarique Parwez provides diagnosis and individualized non-operative and operative treatment plans in Hertfordshire, Luton, Hatfield. Mr Tarique Parwez also provides highly specialized care during and after the surgery. Contact Mr Tarique Parwez’s office for an appointment today!

Information about COVID-19 (Coronavirus)

On 11 March 2020 the World Health Organization confirmed COVID-19 (coronavirus) has now spread all over the world (this means it is a ‘pandemic’). Hospitals have very robust infection control procedures, however, it is impossible to make sure you don’t catch coronavirus either before you come into the hospital or once you are there. You will need to think carefully about the risks associated with the procedure, the risk of catching coronavirus while you are in hospital, and of not going ahead with the procedure at all. Your healthcare team can help you understand the balance of these risks. If you catch the coronavirus, this could affect your recovery and might increase your risk of pneumonia and even death. Talk to your healthcare team about the balance of risk between waiting until the pandemic is over (this could be many months) and going ahead with your procedure.

Please visit the World Health Organization website: for up-to-date information.

Information about your procedure

Following the Covid-19 (coronavirus) pandemic, some operations have been delayed. As soon as the hospital confirms that it is safe, you will be offered a date. Your healthcare team can talk to you about the risks of having your procedure if you have coronavirus. It is then up to you to decide whether to go ahead or not. The benefits of the procedure, the alternatives and any complications that may happen are explained in this document. If you would rather delay or not have the procedure until you feel happy to go ahead, or if you want to cancel, tell your healthcare team.

If you decide to go ahead, you may need to self-isolate for a period of time beforehand (your healthcare team will confirm how long this will be). If you are not able to self-isolate, tell your healthcare team as soon as possible. You may need a coronavirus test a few days before the procedure. If your test is positive (meaning you have coronavirus), the procedure will be postponed until you have recovered.

Coronavirus spreads easily from person to person. The most common way that people catch it is by touching their face after they have touched anyone or anything that has the virus on it. Wash your hands with alcoholic gel or soap and water when you enter the hospital, at regular intervals after that, and when you move from one part of the hospital to another.

Even if you have had the first or both doses of a Covid vaccine, you will still need to practise social distancing, hand washing and wear a face covering when required.

If your healthcare team need to be close to you, they will wear personal protective equipment (PPE). If you can’t hear what they are saying because of their PPE, ask them to repeat it until you can. Chairs and beds will be spaced apart. You may not be allowed visitors, or your visiting may be restricted.

Your surgery is important and the hospital and health professionals looking after you are well equipped to perform it in a safe and clean environment. Guidance about coronavirus may change quickly ─ your healthcare team will have the most up-to-date information.

What is arthritis?

Arthritis is a group of conditions that cause damage to one or more joints.

Your surgeon has recommended a unicompartmental knee replacement operation. However, it is your decision to go ahead with the operation or not. This document will give you information about the benefits and risks to help you to make an informed decision. If you have any questions that this document does not answer, ask your surgeon or the healthcare team.

How does arthritis happen?

A unicompartmental knee replacement

The most common type of arthritis is osteoarthritis, where there is gradual wear and tear of a joint. For a few people this is a result of a previous problem or injury but usually it happens without a known cause.

Arthritis eventually wears away the normal cartilage covering the surface of the joint and the bone underneath becomes damaged. This causes pain and stiffness in the joint, which can interfere with normal activities. If only part of your knee is damaged by arthritis, you can sometimes have a unicompartmental knee replacement instead of a total knee replacement.

What are the benefits of surgery?

You should get less pain and be able to walk more easily. A unicompartmental knee replacement may bend better and feel more like a normal knee than a total knee replacement.

Are there any alternatives to a knee replacement?

Simple painkillers such as paracetamol and

anti-inflammatory painkillers such as ibuprofen can help control the pain of arthritis. Check with your doctor before you take supplements.

Using a walking stick on the opposite side to the affected knee can make walking easier. Wearing an elasticated support on your knee can help it feel stronger.

Regular moderate exercise can help to reduce stiffness in your knee. Physiotherapy may help to strengthen weak muscles. If you are overweight, losing weight will help reduce the load on your knee.

A steroid injection into your knee joint can sometimes reduce pain and stiffness for several months. You may get side effects if you have injections too often. You should not have a steroid injection within 2 weeks of having a vaccination because it can prevent you from making enough antibodies. Your surgeon may recommend injections with special lubricating fluid or plasma.

An operation called a tibial osteotomy changes the shape of your leg and can take the load off the worn part of your knee.

All these measures become less effective if your arthritis gets worse and this is when your surgeon may recommend a knee replacement.

What will happen if I decide not to have the operation?

Arthritis of your knee usually, though not always, gets worse with time. Arthritis is not

life-threatening in itself but it can be disabling. Arthritis symptoms can be worse at some times than others, particularly when the weather is cold.

What does the operation involve?

The healthcare team will carry out a number of checks to make sure you have the operation you came in for and on the correct side. You can help by confirming to your surgeon and the healthcare team your name and the operation you are having.

Various anaesthetic techniques are possible. Your anaesthetist will discuss the options with you. You may also have injections of local anaesthetic to help with the pain after the operation. You may be given antibiotics during the operation to reduce the risk of infection. The operation usually takes an hour to 90 minutes.

Your surgeon will make a cut on the front of your knee and will check that your knee is suitable for a unicompartmental replacement. If there is any damage in other parts of your knee, you may need to have a total knee replacement instead.

Your surgeon will remove the damaged joint surfaces. They will replace these with an artificial knee joint made of metal, plastic or ceramic, or a combination of these materials.

Your knee replacement is fixed to the bone using acrylic cement or special coatings on your knee replacement that bond directly to the bone.

Your surgeon will close your skin with stitches or clips.

What should I do about my medication?

Make sure your healthcare team knows about all the medication you take and follow their advice. This includes all blood-thinning medication as well as herbal and complementary remedies, dietary supplements, and medication you can buy over the counter.

What can I do to help make the operation a success?

If you smoke, stopping smoking now may reduce your risk of developing complications and will improve your long-term health.

Try to maintain a healthy weight. You have a higher risk of developing complications if you are overweight.

Regular exercise should help to prepare you for the operation, help you to recover and improve your long-term health. Before you start exercising, ask the healthcare team or your GP for advice.

You can reduce your risk of infection in a surgical wound.

  • In the week before the operation, do not shave or wax the area where a cut is likely to be
  • Try to have a bath or shower either the day before or on the day of the
  • Keep warm around the time of the Let the healthcare team know if you feel cold.
  • If you are diabetic, keep your blood sugar levels under control around the time of your

If you have not had the coronavirus (Covid-19) vaccine yet, ask your healthcare team if this can be done before your operation. This will reduce your risk of serious illness related to Covid-19 while you recover.

What complications can happen?

The healthcare team will try to reduce the risk of complications.

Any numbers which relate to risk are from studies of people who have had this operation. Your doctor may be able to tell you if the risk of a complication is higher or lower for you.

Some complications can be serious and can even cause death.

You should ask your doctor if there is anything you do not understand.

Your anaesthetist will be able to discuss with you the possible complications of having an anaesthetic.

General complications of any operation

  • Bleeding during or after the You may need a blood transfusion.
  • Infection of the surgical site (wound) (risk: 1 in 600). It is usually safe to shower after 2 days but you should check with the healthcare Keep your wound dry and covered. Let the healthcare team know if you get a high temperature, notice pus in your wound, or if your wound becomes red, sore or painful. An infection usually settles with antibiotics but you may need special dressings and your wound may take some time to heal. In some cases another operation might be needed. Do not take antibiotics unless you are told you need them.
  • Allergic reaction to the equipment, materials or The healthcare team is trained to detect and treat any reactions that might happen. Let your doctor know if you have any allergies or if you have reacted to any medication or tests in the past.
  • Acute kidney injury. A significant drop in your blood pressure during the operation can damage your kidneys. The healthcare team will monitor your condition closely to reduce the chance of this Any kidney damage is usually short lived although some people may need to spend longer in hospital and a small number can go on to develop chronic kidney disease that may require dialysis.
  • Difficulty passing urine. You may need a catheter (tube) in your bladder for 1 to 2
  • Blood clot in your leg (deep-vein thrombosis – DVT). This can cause pain, swelling or redness in your leg, or the veins near the surface of your leg to appear larger than However, most blood clots are small and settle without causing any problems. The healthcare team will assess your risk. They will encourage you to get out of bed soon after the operation and may give you injections, medication, or inflatable boots or special stockings to wear. Let the healthcare team know straight away if you think you might have a DVT.
  • Blood clot in your lung (pulmonary embolus), if a blood clot moves through your bloodstream to your lungs (risk: 1 in 200). Let the healthcare team know straight away if you become short of breath, feel pain in your chest or upper back, or if you cough up blood. If you are at home, call an ambulance or go immediately to your nearest Emergency
  • Chest infection. You may need antibiotics and If you have the operation within 6 weeks of catching Covid-19, your risk of a chest infection is increased (see the ‘Covid-19’ section for more information).
  • Heart attack (where part of the heart muscle dies). A heart attack can sometimes cause
  • Stroke (loss of brain function resulting from an interruption of the blood supply to your brain). A stroke can sometimes cause

Specific complications of this operation

  • Damage to nerves around your knee, leading to weakness, numbness or pain in your leg or
  • Damage to blood vessels behind your knee, leading to loss of circulation to your leg and You will need surgery straight away to restore the blood flow.
  • Bearing dislocation, where the piece of plastic in the middle of your knee replacement comes out of place (risk: 1 in 100). This can only happen with some types of unicompartmental knee You will need another operation.
  • Infection in your knee, which can result in loosening and failure of your knee replacement (risk: 1 in 200). You will usually need one or more further operations to control the infection. If you get any kind of infection, including a dental infection, get it treated straight away as the infection could spread to your
  • Loosening without infection. You may need another operation to do your knee replacement again (risk: 1 in 70 in the first 10 years). You may need to have a total knee
  • Severe pain, stiffness and loss of use of your knee (complex regional pain syndrome). The cause is not known. You may need further treatment including painkillers and Your knee can take months or years to improve. Sometimes there is permanent pain and stiffness.


A recent Covid-19 infection increases your risk of lung complications or death if you have an operation under general anaesthetic. This risk reduces the longer it is since the infection. After 7 weeks the risk is no higher than someone who has not had Covid-19. However, if you still have symptoms the risk remains high. The risk also depends on your age, overall health and the type of surgery you are having.

You must follow instructions to self-isolate and take a Covid-19 test before your operation. If you have had Covid-19 up to 7 weeks before the operation you should discuss the risks and benefits of delaying it with your surgeon.

Consequences of this procedure

  • The healthcare team will give you medication to control the pain and it is important that you take it as you are told so you can move about as advised.
  • Unsightly scarring of your skin, although knee-replacement wounds usually heal to a neat

How soon will I recover?

In hospital

After the operation you will be transferred to the recovery area and then to the ward. You will usually have an x-ray to check the position of your knee replacement.

The physiotherapist will help you to start walking using crutches or a walking frame, usually the next day. Getting your knee to bend takes hard work.

Keep your wound dry for 4 to 5 days, and use a waterproof dressing when you have a bath or shower. The healthcare team will tell you if you need to have any stitches or clips removed, or dressings changed.

You should be able to go home after 1 to 4 days. However, your doctor may recommend that you stay a little longer.

If you are worried about anything, in hospital or at home, contact the healthcare team. They should be able to reassure you or identify and treat any complications.

Returning to normal activities

To reduce the risk of a blood clot, make sure you carefully follow the instructions of the healthcare team if you have been given medication or need to wear special stockings.

The healthcare team will tell you when you can return to normal activities. To reduce the risk of problems, it is important to look after your new knee as you are told.

You may need to use a walking aid for a few weeks.

You will often notice a patch of numb skin next to the scar on your knee. This is normal after knee replacement surgery and usually becomes less noticeable with time.

Regular exercise should help you to return to normal activities as soon as possible. Before you start exercising, ask the healthcare team or your GP for advice.

Do not drive until you can control your vehicle, including in an emergency, and always check your insurance policy and with the healthcare team.

Ask your healthcare team if you need to do a Covid-19 test when you get home.

The future

Most people make a good recovery, have less pain, and can move about better. An artificial knee never feels quite the same as a normal knee. You can usually expect to be able to bend your knee to 120 degrees or more.

A unicompartmental knee replacement can wear out with time. This depends on your body weight and how active you are. Eventually a worn knee replacement will need to be replaced. About 19 in 20 unicompartmental knee replacements will last 10 years.

You can get arthritis in the parts of your knee that have not been replaced. If the pain is severe, you may need another operation to to take out your unicompartmental knee replacement and put in a total knee replacement (risk: 1 in 50).


Arthritis of your knee usually happens without a known cause. It can sometimes affect only part of your knee. If you have severe pain, stiffness and disability, a unicompartmental knee replacement should reduce your pain and help you to walk more easily.

Surgery is usually safe and effective but complications can happen. You need to know about them to help you to make an informed decision about surgery. Knowing about them will also help to detect and treat any problems early.

Unicompartmental Knee Replacement

Oxford Unicompartmental Knee Replacement

If you would like to have additional information on the treatment of various knee conditions or would like to learn more about unicondylar knee replacement, please contact Mr Tarique Parwez, serving the communities of Hertfordshire, Luton, Hatfield.