gms | German Medical Science

54. Jahrestagung der Norddeutschen Orthopädenvereinigung e. V.

Norddeutsche Orthopädenvereinigung

16.06. bis 18.06.2005, Hamburg

Eversion or subluxation of patella in soft tissue balancing of total knee arthroplasty?: results of a cadaver experiment

Meeting Abstract

  • corresponding author C. Lüring - Orthopädische Klinik Universität Regensburg, Unfallchirurgische Abteilung Medizinische Hochschule Hannover, Orthopädische Klinik, Bad Abbach
  • T. Hüfner - Hannover
  • D. Kendoff - Hannover
  • L. Perlick - Regensburg
  • H. Bäthis - Regensburg
  • C. Krettek - Hannover
  • J. Grifka - Regensburg

Norddeutsche Orthopädenvereinigung. 54. Jahrestagung der Norddeutschen Orthopädenvereinigung e.V.. Hamburg, 16.-18.06.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc05novEP82

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

Published: June 13, 2005

© 2005 Lüring 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.




Correct postoperative leg alignment and stability of total knee prothesis over the full range of movement is one critical factor for successful TKA. This can only be achieved by correct implantation of prothesis and soft tissue handling. Still arthrotomy, surgical approach and handling of patella are discussed controversially.

Materials and Methods

In a cadaver specimen study we evaluated the influence of everted or subluxated patella on limb axis during balancing of the knee in three different standard surgical approaches. For each approach we operated five knees. Leg alignment was visualised by Ci® CT-free DePuy/BrainLAB navigation system. First, physiological leg alignment was measured. Then the different approaches were performed and a.p. leg axis was first measured and compared as well with everted as with subluxed patella in extension and second in 90 degrees flexion.


Eversion of patella leads to a falsification of leg axis compared to subluxed patella of 0,58 degrees (SD: 0,03, range: 0,54°-0,6°) limb axis in valgus direction in full extension. In 90 degrees flexion we found a mean deviation of leg axis of 0,48 degrees (SD: 0,11, range: 0,38°-0,6°) with everted patella compared to subluxed patella.


The surgeon has to be aware of this falsifying influence of everted patella to the a.p. limb axis.