[Possibilities of using ultrasonic tools in changing endoprostheses].

In joint replacement surgery an exchange of endoprostheses is technically most difficult, time consuming, and extremely unpleasant for the patient. Removal of the implant without damaging the bone entails many problems. Experience has shown that, in addition to the normal operative technique, the ultrasonic method may be very helpful. Ultrasonic implements that melt thermoplastic implants facilitate the removal of those implants (e.g., polymethylmethacrylate, polyethylene), protect the tissue, and save time. This method is not an alternative to the normal operative technique, but an additional help.