frequently asked questions on artificial joints

How long can I expect my artificial joint to last?

According to recent international studies, 95% of all implants remain free of any complications or significant attrition after 10 years, and 90% remain in good shape even after as long as 20 years. On top of everything, one has to bear in mind that these statistics reflect the quality of implants used one or two decades ago. Thanks to technological improvements today's products are expected to provide an even longer life cycle.

Which materials are used? How is the prosthesis positioned?

There are two alternatives of fixation: with or without bone cement. Both of them have their pros and cons. On the basis of clinical and radiological tests the surgeon has to decide which alternative is more appropriate for the individual patient.

For cementless prostheses, products made of titanium or suitable titanium alloys have proven valuable, whereas cemented prostheses are made of chrome-cobalt alloys. The wear couples of the cups can be made of a range of materials, such as polyethylene, ceramics or metal. For the ball heads, ceramic or metal components are predominantly used. In knee joint replacements, wear couples are always constructed using polyethylene/metal combinations.

How long does it take to replace a joint?

Routinely, a hip or knee replacement takes about 60 to 90 minutes, measured from the beginning to the end of the narcosis.

Minimal invasive surgery (MIS) is preferred whenever possible for both total hip and total knee arthroplasty. These conservative techniques imply small skin incisions and musculature-sparing surgery, thus significantly faster rehabilitation.

Which products do I prefer to use?

I personally prefer the cement free fixation of hip endoprostheses, as I have gained experiences in this field for decades and have been very satisfied with the results. Typically, I employ the hip implant system Alloclassic^® Variall™ by Zimmer Germany GmbH. The cementless titanium cup is screwed into the acetabulum; the conical, "press-fit" diaphysis (shaft) is made of titanium alloy. This system offers various combinations of wear couples which can be matched with the individual needs of the patient.

For a total knee arthroplasty I preferably use the NexGen™ System by Zimmer. This is another state-of-the-art implant coming with a wide range of customizable features, thus allowing for an optimal adaptation to the patient's specific situation.

If you have further questions concerning hip and knee replacements, please do not hesitate to contact me.