gms | German Medical Science

54. Jahrestagung der Norddeutschen Orthopädenvereinigung e. V.

Norddeutsche Orthopädenvereinigung

16.06. bis 18.06.2005, Hamburg

Primary stability of open wedge high tibial osteotomy: a biomechanical study of four implants

Meeting Abstract

  • corresponding author D. Freiling - Henriettenstiftung Hannover, Unfall-und Wiederherstellungschirurgie, Hannover
  • D. Agneskirchner - Hannover
  • D. Hurschler - Hannover
  • P. Lobenhoffer - Hannover

Norddeutsche Orthopädenvereinigung. 54. Jahrestagung der Norddeutschen Orthopädenvereinigung e.V.. Hamburg, 16.-18.06.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc05novEP71

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

Published: June 13, 2005

© 2005 Freiling 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.




This biomechanical study investigated the primary stability of different implants for open wedge high tibial osteotomy (HTO).

Materials and methods

17 sawbone 3rd generation composite tibiae were used for testing. 4 plates with different designs were tested: short spacer plate (OWO) (n=4), short spacer plate with multidirectional locking bolts (MSO) (n=5), prototype version of long spacer plate with multidirectional locking bolts (MSOnew), (n=2), long medial tibia plate fixator (MPF) (n=4). All osteotomies were performed by one surgeon (PL) in a standardized fashion. The proximal and distal end of the tibia were embedded in a specially designed mounting fixture. Axial compression of the tibiae with a standardized alignment of the loading axis was performed using a material testing machine. Single load to failure tests as well as load-controlled cyclical failure tests were performed. The required force and time to failure were recorded as well as the gap motion between the proximal and distal segment using linear displacement transducers.


Failure occurred at the lateral cortex in all tested implants. Significant differences were found regarding force and time to failure with the MPF being the construct with the highest resistance. Displacements at the important medial osteotomy gap were significantly different. The MPF showed the lowest medial displacement, followed by the OWO, MSO and at least by the MSOnew plate.


The implant design strongly influences the primary stability of open wedge HTO. The best results were obtained with a long plate fixator with locked bolts.