Unicompartmental Knee Replacement

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

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. 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.

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.

Simple painkillers such as paracetamol and anti-inflammatory painkillers such as ibuprofen can help control the pain of arthritis.

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.

Physiotherapy may help to strengthen weak muscles.

A steroid injection into your knee joint can sometimes reduce pain and stiffness for several months.

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

Various anaesthetic techniques are possible. 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.

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.

You should be able to go home after 1 to 4 days.

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

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.

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.

A unicompartmental knee replacement can wear out with time.

Some complications can be serious and can even cause death.

General complications of any operation

• Pain
• Bleeding
• Infection of the surgical site (wound)
• Unsightly scarring of your skin
• Difficulty passing urine
• Blood clot in your leg
• Blood clot in your lung
• Chest infection
• Heart attack
• Stroke

Specific complications of this operation

• Damage to nerves around your knee
• Damage to blood vessels behind your knee
• Bearing dislocation, where the piece of plastic in the middle of your knee replacement comes out of place
• Infection in your knee
• Loosening
• Severe pain, stiffness and loss of use of your knee