Sheep Hip Arthroplasty Model of Failed Implant Osseointegration
Thomas Jakobsen*, 1, Søren Kold2, Jørgen Baas1, Kjeld Søballe1, Ole Rahbek1
Identifiers and Pagination:Year: 2015
First Page: 525
Last Page: 529
Publisher ID: TOORTHJ-9-525
Article History:Received Date: 13/4/2015
Revision Received Date: 26/8/2015
Acceptance Date: 3/9/2015
Electronic publication date: 13/11/2015
Collection year: 2015
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
Early secure stability of an implant is important for long-term survival. We examined whether micromotion of implants consistently would induce bone resorption and formation of a fibrous membrane and thereby prevent osseointegration.
One micromotion implant was inserted into one of the medial femoral condyles in ten sheep. The micromotion device consists of an anchor bearing a PMMA implant and a PE plug. During each gait cycle the PE plug will make the PMMA implant axially piston 0.5 mm. After 12 weeks of observation the bone specimens were harvested and a post-mortem control implant was inserted into the contra-lateral medial femoral condyle.
Histomorphometrical evaluation showed that the surface on the implant observed for 12 weeks was covered by fibrous tissue. The control implants were covered by lamellar bone. No difference was found with respect to the volume fraction of lamellar bone in a 1 mm zone around the implants.
This study indicates that implant micromotion is sufficient to induce bone resorption and formation of a fibrous membrane.