Author's School

Graduate School of Arts & Sciences

Author's Department/Program

Movement Science

Language

English (en)

Date of Award

Winter 1-1-2012

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Chair and Committee

David R Sinacore

Abstract

Charcot neuropathic osteoarthropathy: CN) is characterized by progressive degradation of bones and joints in a denervated, inflamed foot and ankle. Diabetes mellitus: DM) and peripheral neuropathy: PN) are the most common precursors of CN, which can lead to pedal fracture, subluxation, and dislocation. Bone injury and subtle articular damage characteristic of incipient CN are difficult to visualize with planar radiographs. As a result, CN often progresses until more serious, clinically obvious events occur, contributing to increased risk of ulceration, infection, amputation, and death.

The overall purpose of this research was to develop methods using volumetric quantitative computed tomography: vQCT) to assess foot bone strength and foot deformity, in order to provide improved indices of CN onset and progression. Aim 1 describes the development of methods to assess bone mineral density: BMD) and geometric bone strength indices in human metatarsals, as well as an ex vivo validation of ultimate loading strength using cadaver samples. Results in Aim 1 showed that BMD and indices of compressive, bending, and buckling strength were strong correlates of metatarsal ultimate strength. Aim 2 provides group comparisons of vQCT-derived bone strength indices between CN and non-CN individuals, with results showing large decrements in BMD in individuals with CN, though no group differences were found for geometric strength indices. Aim 3 presents method development and reliability assessment of novel 3D techniques to assess foot deformities using bone surface atlases of the tarsal and metatarsal bones, with results suggesting that an automated, template-based method can provide equivalent measurement precision to expert testers. In Aim 4, vQCT-derived, 3D foot deformity measures were compared between CN and non-CN individuals; results showed significant alterations in bone-to-bone orientations that corroborate sagittal plane measurements from X-rays and also provide novel deformity measures that cannot be made using uni-planar X-rays.

This dissertation research, completed under the direction of an interdisciplinary team of physical therapists, biomedical engineers, radiologists, and orthopedic surgeons, provides new information regarding bone strength and foot deformities in Charcot neuropathic osteoarthropathy. Most importantly, the tools developed in the course of this research have potential utility for future research to understand the pathophysiological pathways linking diabetes, peripheral neuropathy, foot deformities, and the development and progression of Charcot neuropathic osteoarthropathy.

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Permanent URL: http://dx.doi.org/10.7936/K7SJ1HPF

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