0
research-article

Plastic Energy Dissipation in Lumbar Spine Implants: A Contact Mechanics Point of View

[+] Author and Article Information
Mohammad Hodaei

Graduate Program in Biomedical Engineering, University of Manitoba, Winnipeg, Canada; Sound and Vibration Laboratory, Department of Mechanical Engineering, University of Manitoba, Winnipeg, Canada
hodaeim@myumanitoba.ca

Ako Bahari

Sound and Vibration Laboratory, Department of Mechanical Engineering, University of Manitoba, Winnipeg, Canada
baharia@myumanitoba.ca

Pooneh Maghoul

Graduate Program in Biomedical Engineering, University of Manitoba, Winnipeg, Canada; Department of Civil Engineering, University of Manitoba, Winnipeg, Canada
poonehm2001@yahoo.com

Vahid Rabbani

Sound and Vibration Laboratory, Department of Mechanical Engineering, University of Manitoba, Winnipeg, Canada
rabbaniv@myumanitoba.ca

1Corresponding author.

ASME doi:10.1115/1.4041702 History: Received July 20, 2018; Revised October 08, 2018

Abstract

In the current study, an elasto-plastic contact model is developed for $L_1$ through $L_5$ lumbar spine implants. Roughness effect is included to estimate energy loss which is an indication of wear and subsequently the issue of metal debris in body. A Gaussian function is assumed for the distribution of asperities. The contact surfaces of the implants are assumed to be spherical caps. Subsequently a least-square approach is applied to obtain an approximate expression for the contact force using the data from integration over contact zone. The energy loss is calculated, next, which is due to plastic deformations of asperities. The numerical results indicate that for a given loading-unloading condition, the amount of energy dissipation increases in $L_1$ through $L_4$ lumbar spine implants while it decreases from $L_4$ to $L_5$ implants. The implants geometrical specifications are chosen to cover a wide range of patients' age. Finally a closed-form expression is obtained for the plastic energy dissipation per cycle in terms of plastic index for the lumbar spine $L_4$, as the worst-case scenario. Such a function can serve as a very useful tool for implant designers and manufacturers.

Copyright (c) 2018 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Tables

Errata

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