The mechanical properties of the cancellous bone in the laboratory rat animal
model are of great interest to the research community for the evaluation of treatments for
osteoporosis. Cancellous bone responds rapidly and dramatically to disuse, various
pathologies, nutritional deficiencies, and hormonal deficiencies and hence is often a
primary focus in animal studies. Previous methods for evaluating the mechanical
properties of cancellous bone in rat test specimens included both cortical and cancellous
bone. This thesis introduces a new method to core cancellous specimens using a
diamond wire saw in concert with specially designed fixtures. This method has been
termed Isolated Cancellous Coring (ICC). The location and the geometry of the cored
specimens were determined based on uCT analysis. The isolated cancellous specimens
were subjected to uni-axial compression testing to evaluate the mechanical properties.
Furthermore, the new method is evaluated by directly applying it to a study investigating
the effects of estrogen replacement therapy in post-menopausal osteoporosis as
simulated by the ovariectomized rat model.
The results show that the ICC method can be applied to bone specimens with a
large range in density and micro-architecture parameters. The compression testing of the
isolated cancellous specimens provides a sensitive indicator of the effects of
osteoporosis and treatment on the mechanical properties of the cancellous bone in the
distal rat femur. Also, the results indicate a possible discordant relationship between
bone mineral density and bone strength with respect to estrogen treatment. Power law regressions show that approximately 50% of the variation in ultimate strength can be
accounted for with bone mineral density and the percent of bone volume per total
volume.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2009-08-1616 |
| Date | 14 January 2010 |
| Creators | Lucas, Matthew W. |
| Contributors | Hogan, Harry A., Bloomfield, Susan A. |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis |
| Format | application/pdf |
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