Prof. Dr. Christoph Lohmann

Dear Professor Lohmann, what was the reason for your decision to implant balanSys BICONDYLAR?

Prof. Lohmann: I was looking for an alternative to the “mobile bearing” platforms we had been using until then, and wanted to switch to a “fixed bearing” platform. The balanSys BICONDYLAR prosthesis made a reliable impression on me at the time. I was very impressed by the results I had seen from other colleagues. Comparing this with other implants, I saw clinical improvements, such as significantly better bending ability, and patients had less pain in the course. Therefore I switched to the Mathys system.

What did you dislike about the “mobile bearing” implants?

Prof. Lohmann: With the “mobile bearing” implants, the metal parts of the prosthesis are fixed in the tibia and femur. The mobile platform is then supposed to fit in within certain limits so that it stands stably in between. However, in my experience, with the non-cross-linked inlays that were standard at the time, wear is rather high. The mobile platforms may also happen to rotate, which then provokes pain. For this reason I wanted to switch to “fixed bearing” prostheses. In their case, the polyethylene component is clicked into the tibial metal component and is very stable. This does mean that the tibial and femoral components must have been well aligned beforehand, but in practice this is usually not a problem. The “fixed bearing” implants also allow some degree of rotation and are not rigid.

“Polyethylene with vitamin E reduces the risk of oxidation and ensures longevity”

Why do you think the system is still “state of the art” today?

Prof. Lohmann: The polyethylenes used in balanSys BICONDYLAR have evolved and improved greatly. The polyethylene inlay is the weak point of any knee prosthesis. Today, the vitamin E-enriched polyethylene vitamys is used, which enables a significant increase in longevity, especially for knee prostheses. The vitamin E in the inlay has a preventive effect on oxidation. In addition, the polyethylene is highly cross-linked, making the prosthesis more resistant to wear. Thanks to these further developments, balanSys BICONDYLAR is state of the art.

How do you rate the possibility of a comprehensive prosthesis portfolio as offered by balanSys BICONDYLAR?

Prof. Lohmann: As a matter of principle, this is a positive development. We use the various prostheses with differing frequencies. For example, many of our patients have advanced osteoarthritis. Therefore, it is not always possible to preserve the posterior cruciate ligament – in many cases it is already very damaged. Therefore we prefer to implant prostheses that compensate for the function of both cruciate ligaments.

Another advantage of balanSys BICONDYLAR is the “leggera” instrumentation. During the decision-making process, that convinced me as much as the prosthesis itself did. It makes implantation easier. In this way, the saw guides can be positioned more accurately, and the ligament tension optimised. The prosthesis can thus be positioned very precisely. The balancing of the knee joint is also improved by the instrumentation set.

There are some long-established prosthesis designs. Where do you think the balanSys BICONDYLAR prostheses make the difference?

Prof. Lohmann: There are many good and very good knee prostheses on the market. I would rank balanSys BICONDYLAR among the very good implants. As a surgeon, I choose a prosthesis that I can handle well, that feels good in my hand. Then, in my hospital there is another crucial point: We train young surgeons. A robust system is needed for this. It should be plausible, easy to handle, and not too complicated. All in all, the balanSys BICONDYLAR prosthesis is technologically top-notch and reliable as well as ideally suited for training.

“Implantation of balanSys BICONDYLAR is intuitive”

You talk about the prosthesis being easily manageable. In your opinion, is it easy to switch to the balanSys BICONDYLAR system?

Prof. Lohmann: I think so. The prosthesis is not rocket science, but really straightforward. The surgical technique is clearly structured. The instrumentation is very stable. Depending on the surgical technique, either the “tibia first” or the “femur first” technique can be used. There is no need for a major change in the surgeon’s approach. As with any new system, training is of course necessary – ideally, this can be done by attending cadaver workshops or practising on artificial bones (“saw bones”). Work shadowing with experienced users is ideal, of course.

What are the benefits for the patients, from your point of view?

Prof. Lohmann: For the patients, the good mobility is the most important message, apart from the long service lives. I also find the specially developed variant with a reduced allergy risk very advantageous. The system is identical, but the metal is coated. Overall, I see a high level of satisfaction in my patients with balanSys BICONDYLAR. This certainly has something to do with the preparation for the surgery, the surgery itself, the rehabilitation and the motivation we give the patients. But the implant also plays a very important role.


Professor Lohmann, thank you for this interview!