The number of screws, bone quality, and friction coefficient affect acetabular cup stability

Jui Ting Hsu, Chih Han Chang, Heng Li Huang, Mark E. Zobitz, Weng Pin Chen, Kuo An Lai, Kai Nan An

Research output: Contribution to journalArticle

59 Citations (Scopus)

Abstract

One of the major causes of loosening of cementless acetabular cup implants is insufficient initial stability. This study used three-dimensional finite element models of the pelvis and acetabular components to investigate the effects of the number of screws, bone quality, and friction coefficient of the acetabular cup on the initial stability under normal walking. A commercially available hemispherical acetabular cup with five screw holes was used as the default model. The stiffness of the pelvis and the friction coefficient of the cup were systematically varied, within a realistic range, to assess the initial stability of the acetabular cup. The simulations showed that the inserted screws provide only a localized reduction in the relative micromotion between the cup and pelvis therefore inserting several screw closed together might not be useful. Changes in the pelvic stiffness have a non-linear effect on the initial stability of acetabular cup and the subchondral bone provides good support for fixation of the cementless cup. The friction coefficient of the acetabular cup plays a limited role, comparing with the factor of bone quality, in resisting relative micromotion in the cup-pelvis interface.

Original languageEnglish (US)
Pages (from-to)1089-1095
Number of pages7
JournalMedical Engineering and Physics
Volume29
Issue number10
DOIs
StatePublished - Dec 2007

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Bone Screws
Friction
Pelvis
Bone
Stiffness
Bone and Bones
Walking

Keywords

  • Acetabular cup
  • Bone quality
  • Coefficient of friction
  • Finite element method
  • Initial stability
  • Screw fixation

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine
  • Psychology(all)

Cite this

Hsu, J. T., Chang, C. H., Huang, H. L., Zobitz, M. E., Chen, W. P., Lai, K. A., & An, K. N. (2007). The number of screws, bone quality, and friction coefficient affect acetabular cup stability. Medical Engineering and Physics, 29(10), 1089-1095. https://doi.org/10.1016/j.medengphy.2006.11.005

The number of screws, bone quality, and friction coefficient affect acetabular cup stability. / Hsu, Jui Ting; Chang, Chih Han; Huang, Heng Li; Zobitz, Mark E.; Chen, Weng Pin; Lai, Kuo An; An, Kai Nan.

In: Medical Engineering and Physics, Vol. 29, No. 10, 12.2007, p. 1089-1095.

Research output: Contribution to journalArticle

Hsu, JT, Chang, CH, Huang, HL, Zobitz, ME, Chen, WP, Lai, KA & An, KN 2007, 'The number of screws, bone quality, and friction coefficient affect acetabular cup stability', Medical Engineering and Physics, vol. 29, no. 10, pp. 1089-1095. https://doi.org/10.1016/j.medengphy.2006.11.005
Hsu, Jui Ting ; Chang, Chih Han ; Huang, Heng Li ; Zobitz, Mark E. ; Chen, Weng Pin ; Lai, Kuo An ; An, Kai Nan. / The number of screws, bone quality, and friction coefficient affect acetabular cup stability. In: Medical Engineering and Physics. 2007 ; Vol. 29, No. 10. pp. 1089-1095.
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