Knee Replacement

What is it?

There are different types of knee replacements.

• Total knee replacement involves removing the entire knee joint and replacing it with a prosthetic implant made from metal and hard plastic.
• Unicompartmental (or partial) knee replacement means removing one of the knee compartments (there are three in total) and replacing this with a prosthetic implant. See our unicompartmental knee replacement page for more information.
• Revision knee replacement is further surgery after your original knee replacement to replace the prosthetic implant. A revision knee replacement may be needed if the implant is no longer functioning correctly, or has become infected, or worn out over time. See our revision knee replacement page for more information.

With a total knee replacement, damaged cartilage and bone is removed and replaced with an artificial knee joint. The procedure is designed to relieve pain and restore function to your knee in the medium to long-term. Over 90% of modern total knee replacements last 15 years or more, significantly improving quality of life.

Who might need it?

You might be offered a total knee replacement if you have advanced osteoarthritis or a serious knee injury which is causing severe pain and stiffness and making it difficult to perform everyday activities. Your knee may be swollen or deformed and you may experience pain even when you are resting. Medication and painkilling injections may no longer be effective. Total knee replacement surgery is suitable for patients of any age but most are aged between 50 and 80.

What to expect

Prior to a total knee replacement, you will undergo a full medical assessment to check your suitability for surgery and discuss what will happen and the potential for complications. You will have an X-ray to show the extent of damage to your knee joint and you may also be given an MRI scan which shows up he soft tissues (cartilage, muscles and ligaments). Before you go into hospital, you will need to make arrangements for your return home after surgery. You will need help with certain activities in the short-term and you may need to make a few simple adaptations to your home environment, such as moving your bed downstairs to avoid having to climb stairs while you are recovering. Your orthopaedic surgeon will discuss these with you in advance.

On the day of surgery, you will normally be given a general anaesthetic which means you will be asleep throughout the procedure. In some cases, you may be given an epidural which means you will be awake but numb from the waist down. A total knee replacement takes one to two hours. The surgeon will make an incision down the front of your knee and remove any damaged bone and cartilage. An artificial knee made from metal and plastic will be fitted and the incision closed. You will be moved to the recovery room where you will be closely monitored as you come round from the anaesthetic.

You will normally stay in hospital between one and three days and can begin using your new knee almost immediately. A physiotherapist will show you exercises to strengthen the leg muscles and help you to regain the use of your knee. You will need to follow your surgeon’s instructions after you return home, including avoiding getting the wound wet while it is healing and doing your exercises regularly to support your recovery.

Benefits of knee replacement surgery

Most patients make a good recovery from knee replacement surgery and are able to enjoy many years of improved knee function and reduced pain. There is a small risk of complications, including the potential for infection or blood clots, but your surgeon will discuss these with you prior to the operation. Over time, all implants will start to wear but you can take steps to preserve the life of your artificial knee for as long as possible, including maintaining a healthy weight and avoiding certain high impact activities.