Abstract
Problem Wrong positioning of the acetabular cup leads to impingement, luxations and limited ROM. To improve the cup position computer assistant navigation systems had been developed. They are expensive, time consuming and sometimes no easy to handle.
Solution A new concept for the implantation of THP will be introduced: The cup position is not orientated as usual according to the body axis, but according to the stem position. Stem and cup are a closed biomechanical system, cup anteversion and inclination will be positioned according CCD angle and torsion of the stem.
With a new mechanical navigation system for the cup with a special cup probe and guiding system the best position is found intraoperatively according to ROM, impingement, luxation and tension of the muscles.
Results 150 patients had been operated. Optime is extended only 4–6 minutes, dysplasia inlays, impingement and luxations had disappered. The system is easy to handle and to sterilize routinely with the other op.-instruments.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
