Abstract
Aims: The purpose of this study was to find out if navigation devices can improve the alignement of knee arthroplasties even in experience surgeons. Methods: An external group of investigators – members of the Department of Epidemiology of the German Research Institute of Rheumatology – designed a prospective randomized study for the anlayzes of the alignement of knee implants with and without the support of a navigation device. Long standing X-rays before and after surgery were performed. The analyzes of X-rays was done in an external department of radiology. The analyzing radiologers didn’t know to which group the X-rays belonged. In total 120 patients with and 120 patients without the use of the Stryker navigation device were analyzed. The results were compared with the Qui square test. Results: There was a significant difference between the group of non navigated and navigated total knee arthroplasties. In the group without navigation system between 3 and 6% of the implants were positioned in mal-alignement of more than 3°. In the navigated group there was no case which differed to far from the ideal mechanical line. Conclusions: Even in the hands of very experienced surgeons the use of a navigation device can improve the alignment of implants. This study could prove it in concern of varus/valgus-position of the femoral and tibial component but also in the flexion/extension-position of the femoral component and the slope of the tibia component. The positioning was much more accurate in the navigated group. There was no case in the navigated group with wrong alignement.
Theses abstracts were prepared by Professor Dr. Frantz Langlais. Correspondence should be addressed to him at EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
