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Numerical simulation of implant-bone interaction following cementless joint replacement
Bibliography: leaves 143-154.
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| Format: | Thesis |
| Language: | English |
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Department of Mechanical Engineering
2014
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| _version_ | 1867614176842612736 |
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| access_status_str | Open Access |
| author | Starke, Gregory Richard |
| author2 | Martin, John |
| author_browse | Martin, John Starke, Gregory Richard |
| author_facet | Martin, John Starke, Gregory Richard |
| author_sort | Starke, Gregory Richard |
| collection | Thesis |
| description | Bibliography: leaves 143-154. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/9258 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:47:53.411Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2014 |
| publishDateRange | 2014 |
| publishDateSort | 2014 |
| publisher | Department of Mechanical Engineering |
| publisherStr | Department of Mechanical Engineering |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/9258 Numerical simulation of implant-bone interaction following cementless joint replacement Starke, Gregory Richard Martin, John Spirakis, Thanos Mechanical Engineering Bibliography: leaves 143-154. The advent of cemented joint replacements has revolutionised the management of patients suffering from chronic arthritis. However, establishing a durable bond between the prosthesis and the surrounding bone remains a considerable problem. As a result, cementless implants have been developed. These components rely on the ingrowth of bone into a porous coating, which covers a portion of the component surface, to achieve the required mechanical interlock. Once mineralised bone tissue has formed within .the porous surface, a stable bond results which will be maintained by the normal bone turnover processes, thereby providing long term attachment. However, one of the problems associated with the use of cementless implants is the unpredictability of the extent of bone ingrowth. The process of osseo-integration is greatly influenced by the magnitude of the micro-motion between the implant and the surrounding bone. Large movements inhibit ingrowth, and may result in the formation of an interfacial fibrous tissue layer. In addition, interface strains will influence the early repair process and guide long term bone remodelling within this region. A numerical model for the prediction of bone formation within the porous surface has been developed. The evolution laws consider the early repair activity, possible fibrous tissue formation, and long term remodelling, as a function of the history of inelastic relative displacements and elastic interface strains. The model is based on the development of an isoparametric interface element, which is suitable for implementation into a non-linear finite element code. In the unbonded condition, the contact is governed by a Coulomb friction formulation. The position and shape of the Coulomb yield surface is altered according to the evolution equations, which govern the development of mineralised tissue within the surface porosity. The strain history and post-operative time are then used to develop a stimulus coefficient, which determines the course of the interface tissue development. If bone tissue is predicted, the subsequent interfacial material will be governed by a remodelling algorithm for the prediction of the long term response. If the bond strength is exceeded, fracture occurs and the joint may open or slide, thus returning to its original, unbonded, state. In the event of large micro-motions, the yield surface and material formulation are altered to include fibrous tissue. The model is used to predict the development of interfacial tissues at the porous surface of a tibial tray component, with a central peg and a PCA (Howmedica, Inc.) femoral stem. Although many factors influence interfacial tissue development, mechanical loads are assumed to be dominant. In the short term, the relationship between micro-motion and interface tissue response has been shown. However, long term remodelling of interfacial tissues has not been widely demonstrated and, therefore, additional experimental data is required to validate the current long term remodelling predictions. 2014-11-05T17:35:43Z 2014-11-05T17:35:43Z 1996 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/9258 eng application/pdf Department of Mechanical Engineering Faculty of Engineering and the Built Environment University of Cape Town |
| spellingShingle | Mechanical Engineering Starke, Gregory Richard Numerical simulation of implant-bone interaction following cementless joint replacement |
| thesis_degree_str | Doctoral |
| title | Numerical simulation of implant-bone interaction following cementless joint replacement |
| title_full | Numerical simulation of implant-bone interaction following cementless joint replacement |
| title_fullStr | Numerical simulation of implant-bone interaction following cementless joint replacement |
| title_full_unstemmed | Numerical simulation of implant-bone interaction following cementless joint replacement |
| title_short | Numerical simulation of implant-bone interaction following cementless joint replacement |
| title_sort | numerical simulation of implant bone interaction following cementless joint replacement |
| topic | Mechanical Engineering |
| url | http://hdl.handle.net/11427/9258 |
| work_keys_str_mv | AT starkegregoryrichard numericalsimulationofimplantboneinteractionfollowingcementlessjointreplacement |