0
TECHNICAL PAPERS

Axisymmetric Finite Element Analysis of a Debonded Total Hip Stem With an Unsupported Distal Tip

[+] Author and Article Information
T. L Norman, V. C. Saligrama, K. T. Hustosky

Departments of Mechanical and Aerospace Engineering and Orthopedics, Musculoskeletal Research Center, P.O. Box 9196, Health Sciences South, West Virginia University, Morgantown, WV 26506-9196

T. A. Gruen, J. D. Blaha

Department of Orthopedics, Musculoskeletal Research Center, P.O. Box 9196, Health Sciences South, West Virginia University, Morgantown, WV 26506-9196

J Biomech Eng 118(3), 399-404 (Aug 01, 1996) (6 pages) doi:10.1115/1.2796023 History: Received March 24, 1994; Revised August 28, 1995; Online October 30, 2007

Abstract

A tapered femoral total hip stem with a debonded stem-cement interface and an unsupported distal tip subjected to constant axial load was evaluated using two-dimensional (2D) axisymmetric finite element analysis. The analysis was performed to test if the mechanical condition suggest that a “taper-lock” with a debonded viscoelastic bone cement might be an alternative approach to cement fixation of stem type cemented hip prosthesis. Effect of stem-cement interface conditions (bonded, debonded with and without friction) and viscoelastic response (creep and relaxation) of acrylic bone cement on cement mantle stresses and axial displacement of the stem was also investigated. Stem debonding with friction increased maximum cement von Mises stress by approximately 50 percent when compared to the bonded stem. Of the stress components in the cement mantle, radial stresses were compressive and hoop stresses were tensile and were indicative of mechanical taper-lock. Cement mantle stress, creep and stress relaxation and stem displacement increased with increasing load level and with decreasing stem-cement interface friction. Stress relaxation occur predominately in tensile hoop stress and decreased from 1 to 46 percent over the conditions considered. Stem displacement due to cement mantle creep ranged from 614 μm to 1.3 μm in 24 hours depending upon interface conditions and load level.

Copyright © 1996 by The American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In