Background: Femoral impaction allografting to reconstitute bone loss during revision hip surgery has shown excellent results. However, limitations with the use of allografts have warranted research to investigate if bone graft substitutes could be a suitable alternative to replace or augment allograft in impaction grafting.;Aims and Methods: The objectives of this thesis were to assess if: The use of hydroxyapatite (HA) in various combinations with allograft will be biologically effective and functionally stable using a cemented impaction grafting technique in an ovine hemiarthroplasty model. The different treatment groups were compared by measuring the ground reaction forces and new bone formation. The addition of mesenchymal stem cells (MSCs) to allograft, HA or an allograft:HA mixture enhances the amount of new bone formation compared with impaction of the scaffold alone in an ovine metaphyseal femoral bone defect model. The architecture of the HA scaffold influences bone formation in an extra-skeletal sheep model.;Results: HA: allograft mixture of up to 90:10 demonstrated similar functional stability and amount of new bone formation as a 50:50 mixture. Addition of MSCs to allograft or a 50:50 allograft:HA mixture enhances the amount of new bone formation compared with unimpacted constructs. HA either alone or combined with MSCs induces bone growth only when constructed in block form and not in identical porous granular form.;Conclusion: HA is a suitable bone substitute to augment allograft and may be replace bone graft completely in impaction grafting of a femoral component. This has important clinical implications as HA is readily available, easy to use in surgery and not associated with the adverse effects encountered with allografts. The use of MSCs in the treatment of osteolysis holds great potential but further work is required to assess if this technology is transferable to humans.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:499200 |
| Date | January 2008 |
| Creators | Dattani, Rupen |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1444261/ |
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