D.Ing. / This thesis studies the application of newer generation engineering materials, specifically carbon fibre reinforced polymers, as bone plates in cases of fractured bones. The application of bone plates subsequent to bone fracture is a very old orthopaedic technique that has always rendered some problems. The rigidity of the bone plate, and thus the plated system as a whole, is of advantage during the healing phase, but of disadvantage later. Bone remodels itself to most efficiently perform the load bearing required of it. In a plated system, the load is born primarily by the plate and therefore protects the underlying bone, leading to osteoporosis and eventual atrophy. All bone plates are made of a material that is totally foreign to the body, and in most cases these are removed after some healing of the bone had occurred. The majority of current research programmes with respect to bone plates are directed towards biodegradable bone plates that reduces in mechanical strength at approximately the same rate as bone gains in its ability to sustain loads. The principle of stimulating bone growth in cases of delayed union and non-union has been studied since the early 1960's. The studies revealed that bone healing can in fact be enhanced by the introduction of a very small electric current to the fracture site. Variations to the mechanisms and position of application of the current, alternating or direct, are well documented. Although the physiological healing process associated with electrical stimulus remains largely unknown, the principle is well established. The phenomenon of galvanic corrosion has been known since the tum of the century. Where two dissimilar materials are in the presence of a conducting media, the more "reactive" of the two materials will react as an anode or electron donor to the other material. An electric current thus will flow from the one material to the other. Having three existing and known phenomena, namely bone plating, bone healing stimulation and galvanic corrosion raises the question of whether these can be combined to yield a solution superior to any current plating mechanism - a plate that would render sufficient mechanical support but act as an electron source and thus as a bone healing stimulus. The purpose of this study is to assess the biological criteria determining the choice of bone plates (inclusive of mechanical, physiological and electrical criteria) and thereafter selecting a material suitable for this dynamic requirement.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:4404 |
| Date | 18 March 2014 |
| Creators | Lourens, Jan Jonathan |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
| Rights | University of Johannesburg |
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