gms | German Medical Science

54. Jahrestagung der Norddeutschen Orthopädenvereinigung e. V.

Norddeutsche Orthopädenvereinigung

16.06. bis 18.06.2005, Hamburg

Computer-assisted total knee replacement - stage of development

Meeting Abstract

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  • corresponding author A. Krückhans - Orthozentrum München, Orthopädische Klinik, Zentrum für Orthopädische Chirurgie und Endoprothetik, München
  • S. Schütz - München
  • P. Tichy - München

Norddeutsche Orthopädenvereinigung. 54. Jahrestagung der Norddeutschen Orthopädenvereinigung e.V.. Hamburg, 16.-18.06.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc05novK2.08

The electronic version of this article is the complete one and can be found online at:

Published: June 13, 2005

© 2005 Krückhans et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.




• Navigation - does it mean longer lasting results?

• CT-based, CT-free, CT-free with ligament balancing - what is changing?


Since 05/2002 we have operated 291 computer-assisted TKR. We have compared the results of the x-rays with those of the conventional surgical technique, determined the bony resection of tibia and femur in relation to the mechanical axis and the leg axis and analyzed 68 ct-based, 45 ct-free, 178 ct-free with ligament-balancing and 51 conventional operated TKR.


The average value of the leg static of each group differ from the reference value around 1°. The alignments of the bony resections to the mechanical axis in the computer-assisted group were nearly identical. We see a broader statistical spread of the leg axis in the group of the computer-assisted operations without ligament-balancing. The statistical spread of the leg axis represents the following tolerance zone of ±3: ct-based 70,6 % , ct-free 83,3%, ct-free with ligament-balancing 93,3%.


It's possible to prove and correct the bony resections with the computer-assisted navigation. With the ligament-balancing we are able to make the flexion gap match the extension gap and to reach an optimal alignment of the leg axis. Abrasion of polyethylene leads to particle disease and loosening of the implant. An exact positioning of the implant and precise alignment of the leg axis minimize the particle disease and estimates a longer lasting result.