Knee Replacement The Basics

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This article was edited and updated on March 22, 2018.

Why does a knee need to be replaced?

As the cartilage around the joint of the knees wears away, the bone is increasingly damaged. Eventually, the ends of the bone will grind together — with no cartilage left at all. Pain, swelling and stiffness may result, and a replacement of the knee joint is often the only option.

There are several conditions which might contribute to the destruction of the cartilage. They are:

When is a knee replacement done?

This is a decision made between the patient and the doctor, but pain usually becomes the main issue. Some tests may be required to rule out other possibilities; others will wait for as long as possible before having the surgery. It truly is a personal decision.

What are the parts of an artificial joint?

The patient and surgeon will most likely discuss the various options when a knee replacement is being considered. There are several options to consider, including whether or not it will be a partial or whole replacement.

Three parts can be replaced.

Sometimes a total knee replacement is not required. There are three parts of the knee which can be replaced (see diagram 2 above):

  1. the patellar component
  2. the femoral component
  3. the tibial component

The replacement parts are usually made of metal or plastic.

What types of knee replacements are there?

Thus far, surgeons have developed several different types of replacements, and one can only guess what new technologies will occur in the future.

For now, here are four of the most common:

There are also two other decisions to make:

Is there "life" after knee replacement?

Of course! Joint replacement operations have proven to be a predictable and successful treatment, and function and quality of life are often greatly improved afterwards. In fact, after joint replacement, athletic and recreational activities often increase.

However, there are guidelines and protocols that you should follow to be sure that you do not do too much too soon. You may never do high-impact aerobics again, but after healing and doing specific exercises to strengthen the muscles that surround the joint, you will probably be able to do more than you ever expected to!

Among the most common activities recommended after a knee replacement and healing and strengthening of muscles have occurred are 3:

So keep your options open, talk to your doctor, and together make the decision when and if a knee replacement is the right decision for you.

Thanks to the two textbooks: Special Populations by On the Edge Fitness Education and Exercise and Arthritis by Stephanie Harris and Gwen Hyatt.

Other related articles (about joints and joint replacements):

I am a BCRPA-certified fitness instructor in Vancouver, BC. I teach four classes at the West End Community Centre in Vancouver, BC, mostly designed for the older adult. The Inevitable Disclaimer: Everything published here expresses only my opinion, based on my training and research. What you do with the information is entirely your own responsibility. I am not liable for any injury you suffer that seems to be related to anything you read here. Always consult your doctor before beginning an exercise program. For other articles, return to the table of contents.

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  1. These three dots behave exactly like a footnote. Click on them and you will get more information about the topic. 

  2. Thanks to the textbook, Special Populations, for its diagram. 

  3. As suggested by the textbook, Exercise and Arthritis