Knee Arthroplasty – The Artificial Knee Joint

Since 2007, almost all implant surgeries in knee arthroplasty performed in our hospital have been using navigational monitoring. That is more than 200 times per year. On average, only about 30 percent of all surgeries performed in Germany are done with this optical/computer support. Regardless of which model of prosthesis is used when implanting a knee joint prosthesis, a straight mechanical leg axis must be reestablished so that the transfer of forces takes place centrally via the joint and so that lateral forces, which would result in unnecessary friction and non-physiological structural strain, can be avoided. The rotation of the prosthesis components must be correct in order to ensure that the joint is guided by balanced tension of the ligaments. If the ligaments are too tight, mobility is impaired and painful; if they are too loose, on the other hand, the result may be instability in terms of weight-bearing with subjective insecure gait or, in rare cases, even luxation of the joint.

A well-structured and tissue-preserving surgical technique helps to prevent additional tissue damage and to minimize mistakes during the implantation. With the help of a navigation system, the above-mentioned parameters can be monitored and changed such that the desired result is achieved. Thus, a possible cause of early failure or untimely degeneration of the implant is eliminated. On the basis of the experiences we have made to date with the use of this system, we are firmly convinced that we are on the right track. We are increasingly using this aid also when implanting hip endoprostheses.

The aim of aftercare is to enable your knee to bear weight as painlessly as possible and to restore the greatest possible mobility so that your quality of life, which was severely reduced as a result of the arthrosis, can be increased significantly once more. Despite all efforts and research, however, the results – and patient satisfaction – following implantation of a knee endoprosthesis are not quite as good as, for example, in the case of hip replacement. The reasons for this are various and are being studied continually by many physicians and implant manufacturers. One important consequence of this observation is that such a surgery should never be performed too early – only when mobility impairment and pain have reduced the quality of life to such an extent that it can simply not go on “like this”. In aftercare, we usually do not distinguish between cementless and cemented knee arthroplasty. You will receive professional care from our Physical Department. The surgery is followed by intensive aftercare with passive motion on a continuous passive motion (CPM) device during your entire inpatient stay.

On the first day after the operation, you will get up from bed under the guidance of a physiotherapist and already take a few steps using crutches. In the next days, you will walk more and practice climbing stairs. But you can only achieve satisfactory mobility of your “new” knee joint if you actively work with us. You should definitely continue doing the exercises you learn during your stay after you get home in order to get a good treatment result and be satisfied.

We generally recommend that after this operation, you accept the offer of follow-up treatment, where you will receive further physiotherapy. This follow-up treatment can be performed as outpatient or inpatient treatment. We will discuss this issue with you on time while you are an inpatient in our hospital. If you want to get follow-up treatment, we will prepare the corresponding documents for submission to your health insurance company and will then usually transfer you directly to a rehabilitation clinic on the day of your release. Of course, other solutions are also possible, and we will be glad to support you in organizing them.

When you are wearing an endoprosthesis, you should get regular check-ups. When you are released from the hospital, you will get a prosthesis pass from us as a reminder. You should keep it together with your other hospital documents in the folder “My New Joint”.

If there are no particular symptoms, your artificial knee should be X-rayed at the end of the follow-up treatment, after twelve months, and then every 2 years so that any possible loosening can be detected and treated in time. Any decision about extending these check-up intervals can be made on a case-by-case basis.