Osteoarthritis of the joints What makes OA so special? We can help
NO. 9


Search for:

Practical Tips for Artificial Knee Joints

Today many orthopaedic surgeons perform even more  knee replacements than hip replacements. Although some surgeons still advise a certain amount of caution, most experts are convinced that artificial knees are at least as successful as artificial hips, or possibly even more so. The following tips offer some important recommendations. For more information, we would also like to refer you to the tips in the two previous issues of ARTHRITIS INFO.

Disclaimer: please go to "Contents" and click "Disclaimer." Thank you.

1. No Artificial Knee Joint Before 70?

Some surgeons used to perform knee replacement surgery only on  patients who were at least 70 years old. However, an increasing number of experts advocate this operation for younger patients as well. In general, the rule is that all other treatment options should have been exhausted. If this is the case and pain is not relieved by non-surgical methods, younger patients can be eligible for this operation, including those who are still professionally active.



2. Model I: Partial Knee Replacement

Frequently, osteoarthritis doesn’t affect the entire joint, but only part of it. In these cases, prostheses can be used that replace only the affected part of the joint.
This is referred to as partial or  unicompartmental knee replacement. Implanting an  unicompartmental knee prosthesis also helps to straighten up the joint, which has changed its position as a result of osteoarthritis. Partial knee replacement can be more effective and durable in patients who place less strain on their joints.



3. Model II: Total Knee Replacement

If osteoarthritis affects the entire knee joint, models are used which are referred to as “total knee prostheses.” Doctors can choose from a wide variety of prostheses, based on the results of their examinations. Often –
but not always – the back side of the kneecap’s surface has to be replaced as well.



4. With or Without Cement?

The existence of high quality bone cement has also made the implantation of artificial knee joints substantially easier. However, in some cases this cement may not be necessary. As with artificial hips, cement-free knee replacements are sometimes recommended in younger patients. While in Europe about 35% of all knee replacements are implanted without cement, and 65% with cement, in the U.S. almost all are cemented. Cement-free implants are sometimes not recommended for heavy smokers, because nicotine may inhibit bony ingrowth.



5. How Long Do Knee Replacements Last Today?

Many clinical studies in major hospitals confirm that the most advanced knee replacements can often be at least as successful as the best artificial hips. These studies indicate that up to 85% of partial or unicompartmental knee replacements and more than 90% of total knee replacements can still be functional after 10 years. However, results do vary significantly. Choosing an experienced surgeon can make an important difference.



6. Satisfied with the Artificial Knee Joint?

Most people are very happy with their decision to have knee replacement surgery. More than 95% of all patients report that they are “satisfied” or even “very satisfied” with the results. Most everyday activities can be taken up again with the artificial joint. However, in rare cases complications or loosening may occur. In addition, certain precautions must be observed, which will be described on the following pages.



7. Important Exercises

It’s important to take good care of your artificial knee joint. That includes doing regular exercises in order to maintain full mobility.  While sitting, alternately extend your leg (1) and then lower it again (2). Your leg should be extended until it is straight, and bent to a 90- degree angle or further. This exercise should be performed carefully and without any jerky movements. It is best to do this exercise three times a day, in the morning, afternoon, and evening, with 10 repetitions each time.
It only takes about two minutes.



8. Be Careful When Going Downstairs

With an artificial knee joint, you can climb stairs again that may have been troublesome in the past. However, particular caution is advised when going downstairs. It takes several weeks for the muscles of the operated leg to get used to the new joint. They don’t yet have their full strength. Therefore, you should hold on firmly to the banister for support and take careful and cautious steps, particularly when going downstairs.



9. Protect Your Knees

With an artificial knee joint, it is best to avoid kneeling whenever possible.
If kneeling cannot be avoided, however, the use of a soft cushion is recommended. You can often find knee cushions in medical supply and equipment stores or online, for example at www.amazon.com. For a homemade cushion, simply use a foam block about two inches thick and sew a cover out of stain-resistant fabric.




10. Important Aids

It’s always a pleasure after a knee replacement operation to be able to take longer shopping trips again.
A simple and popular accessory can give you valuable support while doing so. Modern, lightweight rolling shopping bags, which can be folded up when not in use, make carrying your purchases easier. They can be found in many department and luggage stores, and aren’t expensive. Usually, even the simplest models are more than adequate.



11. Sports that Should be Avoided

Fortunately, you can resume playing many sports with your new knee joint. However, there are a few important limitations.

  1. Ball sports: Any sports that involve high impact, jumping, collisions, or   possible falls, pose risks. These include basketball, soccer, football and some other ball sports.

  2. Certain knee strain: Sports that strain or twist the knee must be avoided, too. Downhill skiing, cross-country hiking, hill climbing, and certain yoga exercises should generally be avoided after knee replacement.



12. Recommended Sports

Recommended sports may include ballroom dancing, hiking, and walking. Long walks offer a particularly simple and healthy form of exercise. In fact, the Japanese government actively promotes walking as a form of preventive care. Swimming and cycling are also possible. When bicycling, be especially careful in traffic, in order to avoid falling. Also, be sure not to position the seat too low. Playing golf is usually allowed, but you should always check with your surgeon first.



► To continue with the next chapter: click here


MyAAS    HELP    Disclaimer    Legal & Privacy    About the American Arthritis Society