Haroon, Md. Yusuf;
(1996)
The adaptation of morphology to function in long bones.
Doctoral thesis (Ph.D), UCL (University College London).
Text
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Abstract
This thesis deals with the structure of equine limb bones. The initial study determined the relative proportion of fields of view occupied by more longitudinal and more oblique collagen in the cortex of the radius and has attempted to relate this information to osteonal type and type of loading. There is a higher, more oblique fraction in the compression cortex which is associated with a higher remodelling activity. The actual orientation pattern of the collagen fibres in the dark and the bright lamellae in secondary osteons in the plane of section in polarised light is determined. Distal condylar fractures of the third metacarpal bones can be substantially explained by underlying structural features of the mineralized cartilage and bone. There is a marked preference to the orientation of the structure of the mineralized cartilage and it tends to cleave in the saggital plane. There are profound differences with age and between individuals in the density of the subchondral bone. Proximal to this, the main trabeculae are plates running in the dorso-palmar direction with small struts running in the medio-lateral direction joining them together. This structure leads to a tendency for a fracture to propagate between the saggital plates. In the skeletal tissues, fractures start either in the anisotropic trabecular bone, at the osseo-chondral junction, or at the tide-mark in the calcified cartilage at the deep surface of the articular cartilage. They may therefore spread in one or in two directions. Wherever the crack initiated, it would propagate catastrophically when it reached the zone of parallel plate structure of the cancellous bone. The structure of the trabecular bone gives maximum strength and protection in the saggital plane in which the bone rotates, but it will yield slightly in the transverse plane and this may have a beneficial energy absorbing role. The disadvantage of this structural organisation is that it offers minimal resistance to fractures in the saggital plane. Further to this, an anisotropic architecture in the articular cartilage of the equine McIII is described and associated with the unidirectional load that the bone undergoes.
Type: | Thesis (Doctoral) |
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Qualification: | Ph.D |
Title: | The adaptation of morphology to function in long bones |
Open access status: | An open access version is available from UCL Discovery |
Language: | English |
Additional information: | Thesis digitised by ProQuest. |
Keywords: | Biological sciences; Equines; Limb bones |
URI: | https://discovery.ucl.ac.uk/id/eprint/10103289 |
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