Type

Journal Article

Authors

John M. O'Byrne
Dermot Brabazon
Stephen A. Brennan

Subjects

Engineering

Topics
mechanical properties bone impaction biomedical engineering mechanical engineering civil engineering materials soil mechanics shear strength

Effect of vibration on the shear strength of impacted bone graft in revision hip surgery (2011)

Abstract Aims: Studies on soil mechanics have established that when vibration is applied to an aggregate, it results in more efficient alignment of particles and reduces the energy required to impact the aggregate. Our aim was to develop a method of applying vibration to the bone impaction process and assess its impact on the mechanical properties of the impacted graft. Methods: Phase 1. Eighty bovine femoral heads were milled using the Noviomagus bone mill. The graft was then washed using a pulsed lavage normal saline system over a sieve tower. A vibration impaction device was developed which housed two 15V DC motors with eccentric weights attached inside a metal cylinder. A weight was dropped onto this from a set height 72 times so as to replicate the bone impaction process. A range of frequencies of vibration were tested, as measured using an accelerometer housed in the vibration chamber. Each shear test was then repeated at four different normal loads so as to generate a family of stress-strain curves. The Mohr-Coulomb failure envelope from which the shear strength and interlocking values are derived was plotted for each test. Phase 2. Experiments were repeated with the addition of blood so as to replicate a saturated environment as is encountered during operative conditions. Results Phase 1. Graft impacted with the addition of vibration at all frequencies of vibration showed improved shear strength when compared to impaction without vibration. Vibration at sixty Hertz was displayed the largest effect and was found to be significant. 3 Phase 2. Graft impacted with the addition of vibration in a saturated aggregate displayed lower shear strengths for all normal compressive loads than that of impaction without vibration. Conclusions Civil engineering principles hold true for the impaction bone grafting procedure. In a dry aggregate the addition of vibration may be beneficial to the mechanical properties of the impacted graft. In our system the optimal frequency of vibration was 60 Hz. Under saturated conditions the addition of vibration is detrimental the shear strength of the aggregate. This may be explained by the process of liquefaction.
Collections Ireland -> Dublin City University -> Publication Type = Article
Ireland -> Dublin City University -> DCU Faculties and Centres = DCU Faculties and Schools
Ireland -> Dublin City University -> Status = Published
Ireland -> Dublin City University -> DCU Faculties and Centres = DCU Faculties and Schools: Faculty of Engineering and Computing: School of Mechanical and Manufacturing Engineering
Ireland -> Dublin City University -> Subject = Engineering: Mechanical engineering
Ireland -> Dublin City University -> DCU Faculties and Centres = DCU Faculties and Schools: Faculty of Engineering and Computing
Ireland -> Dublin City University -> Subject = Engineering: Materials
Ireland -> Dublin City University -> Subject = Engineering
Ireland -> Dublin City University -> Subject = Engineering: Biomedical engineering

Full list of authors on original publication

John M. O'Byrne, Dermot Brabazon, Stephen A. Brennan

Experts in our system

1
Dermot Brabazon
Dublin City University
Total Publications: 162
 
2
Stephen A. Brennan
Dublin City University