gms | German Medical Science

54. Jahrestagung der Norddeutschen Orthopädenvereinigung e. V.

Norddeutsche Orthopädenvereinigung

16.06. bis 18.06.2005, Hamburg

Experimental analysis of the influence of acetabular cup orientation on dislocation of total hip replacement (THR)

Meeting Abstract

  • corresponding author R. Scholz - Universität Leipzig, Orthopädische Klinik und Poliklinik, Leipzig
  • R. Bader - Rostock
  • E. Steinhauser - München
  • G. von Salis-Soglio - Leipzig

Norddeutsche Orthopädenvereinigung. 54. Jahrestagung der Norddeutschen Orthopädenvereinigung e.V.. Hamburg, 16.-18.06.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc05novEP21

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/nov2005/05nov103.shtml

Veröffentlicht: 13. Juni 2005

© 2005 Scholz et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Aims

Malpositioning of implant components plays a significant role in instability of THR. Our aim was the determination of the influence of anteversion of the acetabular cup.

Methods

The biomechanical study was performed on a model which enables different defined implant positions. Rotation of the femoral stem are carried out in different anteversion positions of the acetabular cup with the hip joint in neutral position and in 90° flexion, as well as inclination of the cup. The range of motion (ROM) is determined until impingement or dislocation is evident, as well as the recording of the resisting moment.

Results

While the resisting moment shows minor deviation in several anteversion (AV) positions with the joint in neutral position, being almost independent from the inclination, a major difference is determined with minimal resisting moment with minor retroversion (RV) and with the hip joint in 90° flexion (0,51 Nm/15° RV vs. 3,69 Nm/30° AV). Dislocation occurs very early due to low ROM at retroversion. Variation of inclination of 30° can only increase ROM until dislocation by 2,8°. With same inclinations angles ROM is increased by 38,1° in the 30° AV.

Conclusions

Correct anteversion of the acetabular component is a significant factor in prevention of dislocation. Minor differences in anteversion are more important than inclination variation to improve stability of THR.