Knee replacement surgery replaces your damaged or worn knee joint with an artificial joint to improve pain and movement and improve quality of life. Knee replacement surgery (arthroplasty) is usually only recommended after non-surgical treatments such as pain relief, therapy and muscle strengthening have been tried first. It involves replacing a damaged, worn diseased knee with an artificial joint.

Total knee replacement surgery may be required if one (or both) of your knee joints becomes damaged and causes you persistent pain or problems with everyday activities. Most people receiving a replacement knee are over 65, with women being slightly the more likely recipients. With care, a replacement knee joint will last for 15 -20 years.

Normally the surfaces of a knee joint are lined with cartilage which helps the joint move smoothly, with a high degree of movement and without causing pain. But when the joint surfaces become worn, normal movement becomes painful as the ends of the bones start to rub or grind together and the joint becomes stiff and inflamed.

There are many reasons why the joint lining can become worn or damaged; some common reasons are explained here.

Osteoarthritis in the knee occurs when the cartilage wears, resulting in the bones within the joint rubbing against each other. This leads to increasing pain and restricted movement of the joint. The bones may compensate by growing thicker and producing bony outgrowths to try to repair themselves, but this can cause more friction and pain. Osteoarthritis is the most common reason for knee replacement surgery.

Rheumatoid arthritis can also be a factor. This is where the body’s own immune system (the body’s defence against infection), attacks the lining of the joint, resulting in stiffness and pain.

Traumatic arthritis results from a serious knee injury, such as a fracture, ligament damage or meniscus tear. The impact of the accident also causes mini trauma to the cartilage which, over time, develops into osteoarthritis which causes knee pain and stiffness.

Damage to the ligaments in the knee are very common in sports that require stopping and starting or quickly changing directions. These extreme forces on the knee can result in torn ligaments. The anterior cruciate ligament (ACL) and the medial collateral ligament (MCL) are the most often injured, but the posterior cruciate ligament (PCL) and the lateral collateral ligament (LCL) can also be injured.

Revision knee replacement surgery (replacing the artificial joint) is usually more complicated and often not as effective. This is one reason why knee replacements are less likely to be given to younger patients.

There are two types of surgery performed at Benenden Hospital, depending on the condition of the knee:

Total knee replacement is when both sides of the knee joint are replaced.

Partial knee replacement (or unicompartmental replacement) is when only one side of the joint is replaced. This is a smaller operation with a shorter hospital stay and recovery.

Your initial consultation will, where possible, include tests and diagnostic imaging (X-rays or MRI scans) and an assessment of your fitness for anaesthesia on the same day, to reduce the number of visits you need to make to the hospital You'll also be entered into our Rapid Recovery Programme.

It may be recommended that you start an exercise programme to strengthen your muscles around the joint and increase flexibility before surgery as this can benefit the recovery time after your operation.

On the day of your surgery, you'll meet your consultant and anaesthetist before you're prepared for theatre. Our knee replacement surgery is performed by a highly-skilled team of consultants. The operation itself takes up to an hour and a half, after which you’ll be taken to the recovery room where you’ll be observed until you’re fit to return to your private room.

Your recovery in hospital usually takes around three days and is managed by a highly skilled team of nurses. Every day you’ll be visited by a physiotherapist who’ll help you regain mobility through carefully planned exercise. Your knee will be tender and painful at first and we’ll only let you leave hospital once we're happy that it’s safe for you to do so.

Most people make a good recovery but an artificial knee never feels the same as a normal knee. For instance, kneeling down is not recommended as it is usually uncomfortable. A replacement can also wear out over time.

Recovery times vary depending on the individual patient and the type of surgery carried out. It’s important to follow the advice given by your surgeon and physiotherapist.

Initially you’ll have a large dressing on your knee to protect your wound and drains to remove blood from the operation site. Nursing staff will change your dressing regularly.

You’ll be encouraged to get up and walk about as quickly as possible. If you’ve had minimally invasive surgery, or are on our Rapid Recovery Programme, you may be able to walk on the same day as your operation. At first you’ll walk with a frame or crutches and most people can walk independently with sticks after about a week.