Engineering and Computer Science Faculty Publications
Axisymmetric Finite Element Analysis of a Debonded Total Hip Stem with An Unsupported Distal Tip
Document Type
Article
Publication Date
8-1996
Journal Title
Journal of Biomechanical Engineering
Volume
118
Issue
3
First Page
399
Last Page
404
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 microns to 1.3 microns in 24 hours depending upon interface conditions and load level.
Recommended Citation
Norman, Timothy L.; Hustosky, K.; and Blaha, J. D., "Axisymmetric Finite Element Analysis of a Debonded Total Hip Stem with An Unsupported Distal Tip" (1996). Engineering and Computer Science Faculty Publications. 231.
https://digitalcommons.cedarville.edu/engineering_and_computer_science_publications/231