Knee replacement

A knee replacement is an artificial knee. Since its introduction in the mid-20th century, the knee replacement, also known as an artificial knee or a new knee, has become indispensable as a surgical treatment for advanced knee osteoarthritis. The first knee replacements were made as hinge joints; these allowed almost no movement and quickly broke under load.

Around 1970, a much improved concept came onto the market. The only problem was still that only two different sizes of knee replacements were available. Today, knee replacements are fully customized, and it is even possible to replace only part of the knee joint, a so-called hemiprosthesis or partial knee replacement.

Research has shown that one in five people over the age of 55 has mild to severe wear of the knee joint. About 20,000 knee replacements are performed each year, 20 to 40 percent of which are hemiprostheses.

Why a knee replacement?

Severe pain when standing for long periods, walking, and especially climbing stairs, reduced mobility of the knee joint, and possibly an (increasing) alignment deformity of the knee. These are just a few features of advanced wear of the knee joint.
The main reasons for a knee replacement are:

• Reducing pain in the knee joint.
• Restoring loss of function in normal daily activities.
• Correcting anatomical (alignment) deformities of the knee joint.

A knee replacement is increasingly chosen as a treatment for advanced wear of the knee joint. Before considering a knee replacement, an extensive process of examinations and measurements is carried out, including an röntgenfoto (X-ray). If this shows that a knee replacement is the best option, the specialist will discuss the various possibilities, including a total knee replacement or hemiprosthesis.

How long does a knee replacement last?

In general, a knee replacement can function well for more than 15 years. Exactly how long it lasts depends on several factors, including overall physical condition, body weight, and the daily load on the knee.

It is possible to replace a knee replacement through revision knee surgery, but the more often this is done, the worse the outcome. Placing a first knee replacement is therefore often postponed as long as possible. If you receive a prosthesis at a young age, it will have to be replaced several times during a lifetime.

What is rehabilitation like after a knee replacement?

In most cases, people can go home the day after surgery. A condition for this is that the knee can be bent reasonably well, enough to get into a car. A second requirement is being able to walk independently to the toilet with the help of crutches.

In general, people recover more quickly from a hemiprosthesis than from a total knee replacement. This is mainly because a hemiprosthesis is a relatively small procedure in comparison, and fewer parts of the knee joint are replaced.

Before the surgery
Today, the rehabilitation process for a hemiprosthesis or total knee replacement is often started a few weeks before the operation, under the guidance of a physical therapist. The underlying idea is ‘better in, better out’, or put simply, an optimal overall physical condition plays an important role in the recovery process after the operation.

During this preoperative phase, the physical therapist will advise and guide you in learning to walk with crutches. He/she will also prepare a number of exercises to be performed in the days after the operation to gradually restore mobility.

After the operation
In the first weeks after the operation, treatment will focus on increasing the mobility of the knee and building up function in daily life. Normally, walking with crutches is gradually reduced during the first six weeks. After these six weeks, provided crutch walking has been successfully phased out, it is permitted to drive a car independently again.

Light-duty work can usually be resumed after six to eight weeks. Rehabilitation after a knee replacement takes an average of six to twelve months.