Vertebral fractures affect at least 12-20% of men and women over the age of 50, and the risk of fracture increases exponentially with age. Despite their high prevalence, the failure mechanisms leading to these fractures are not well understood. For example, clinical observations of fractured vertebra often note that one or both vertebral endplates have collapsed, but the precise involvement of the endplates in the initiation and progression of failure has not yet been defined. The mechanisms of failure may also relate to spatial variations in the density and microstructure of the porous trabecular bone within the vertebra as well as to the health of the adjacent intervertebral discs (IVDs) which transfer loads directly to the vertebral endplates. Delineating the contributions of these factors would shed light on the etiology of vertebral fractures and would aid in development of clinically feasible, patient-specific finite element (FE) models of the vertebra. These models are built from a patient's quantitative computed tomography (QCT) scan and have shown tremendous promise for accurate, patient-specific estimates of bone strength and fracture risk. Further validation studies are required to assess the impact of the choices of material properties and boundary conditions, as a prerequisite for broad implementation of these FE models in clinical care. The overall goal of this work was to define the failure processes involved in vertebral fractures and to evaluate the accuracy of patient-specific FE models in simulating these processes. Mechanical testing of human spine segments, in conjunction with micro-computed tomography, enabled the assessment of deformation at the vertebral endplate and deformation throughout the entire bone, as the vertebra was loaded to failure under both axial compression and anterior flexion. These data were compared against predictions of vertebral deformation obtained from QCT-based FE models. The impact of the choice of boundary conditions was specifically examined by comparing the accuracy of the FE predictions between models that simulated applied loads based on measured distributions of pressure within IVDs and models that used highly idealized boundary conditions. The results of these studies demonstrated that sudden and non-recoverable endplate deflection is a defining feature of biomechanical failure of the vertebra, for both compression and flexion loading. The locations of endplate collapse as vertebral failure progressed were associated with the porosity of the endplate and the microstructure of the underlying trabecular bone. FE analyses incorporating the experimentally observed endplate deflections as boundary conditions provided more accurate predictions of displacements throughout the rest of the vertebra when compared to FE models with highly idealized boundary conditions. Under anterior flexion, the use of boundary conditions informed by measurements of IVD pressure mitigated, but did not eliminate, the inaccuracy of the idealized boundary conditions. No further improvement in accuracy was found when using boundary conditions based on pressure measurements corresponding only to IVDs whose level of degeneration matched that observed in the IVDs adjacent to the vertebra being modeled. Overall, the accuracy of the FE predictions of vertebral deformation was only moderate, particularly near the locations of endplate collapse. The outcomes of this work indicate that the vertebral endplate is principally involved in vertebral fractures and that current methods for QCT-based FE models do not adequately capture this failure mechanism. These outcomes provide a biomechanical rationale for clinical diagnoses of vertebral fracture based on endplate collapse. These outcomes also emphasize that future studies of patient-specific FE models should incorporate physiologically relevant loading conditions and also material properties that more accurately represent the vertebral endplate in order to obtain higher fidelity predictions of vertebral failure.

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<p><strong>Objective: </strong>The objective of this thesis is to identify the approaches to patient-centered care provision currently employed by clinicians and to identify patient perspectives of patient-centeredness in relation to pain and disability following distal radius fracture. This thesis includes a scoping review of patient-centered care frameworks and models, as well as a prospective cohort study.</p> <p><strong>Rationale: </strong>Patient-centered care provision has been linked with positive health outcomes, improved patient satisfaction, and reduced health costs. A uniform approach to patient-centered care in rehabilitation has yet to be developed primarily due to the breadth and scope of practice. Understanding current approaches to patient-centered care and patient perspectives on this care can serve as a foundation to future discussions on the development of a rehabilitation-specific approach to patient-centered care provision.</p> <p><strong>Data sources: </strong>Frameworks and models of patient-centered care provision were located via electronic database searches. The extracted frameworks and models were compared based on how they described strategies on achieving the three tenets of patient-centered care: communication, partnership, and health promotion. A prospective cohort study provided patient perspectives on patient-centeredness, pain, and disability following distal radius fracture at baseline and at three months post distal radius fracture in 129 patients.</p> <p><strong>Methods: </strong>Frameworks and models on patient-centered care provision were extracted from articles and placed in data summary tables for comparison and review. Information on how these frameworks and models described strategies for communication, partnership, and health promotion was collated and reviewed. The patients’ perceptions of patient-centeredness, pain, and disability were determined from responses to the Patient Perceptions of Patient-Centeredness Questionnaire and the Patient Rated Wrist Evaluation. Outcome measure responses were analyzed to measure change over time (Wilcoxon Rank Sum and T-Test analyses) and to identify relationships (Pearson correlations).</p> <p><strong>Results: </strong>The scoping review found 19 articles, from which 25 patient-centered care frameworks or models were identified. All frameworks and models reported strategies on achieving effective communication, partnership, and health promotion. The prospective cohort study revealed significant correlations between patient perspectives of patient-centeredness and pain and disability following distal radius fracture. This suggests that positive experiences with patient-centered care provision are correlated with reduction in pain and improvement in function following an acute orthopaedic injury.</p> <p><strong>Implications: </strong>Until a rehabilitation-specific approach to patient-centered care provision is developed, rehabilitation clinicians can be confident that selection of one of the currently employed frameworks or models of patient-centered care will reflect the three tenets of patient-centered care provision. Adopting one of these patient-centered approaches to care provision likely will result in positive health outcomes.</p> / Master of Science Rehabilitation Science (MSc)

<p><strong>Background:</strong> Despite strong evidence, strategies for improving bone health are underutilized. Knowledge translation (KT) interventions aim to improve uptake of evidence-based practices, however the feasibility and effectiveness of such strategies require further evaluation within Long-term Care (LTC). In this thesis, we examined the impacts of a province-wide osteoporosis strategy and a more intensive multifaceted KT strategy including expert-led educational meetings, audit/feed-back, and action planning for quality improvement. Both studies targeted interdisciplinary LTC teams (physicians, nurses, pharmacists, dietician, and other staff).</p> <p><strong>Methods: </strong>In the first thesis study, we examined the impact of the <em>Ontario Osteoporosis Strategy for LTC</em> by investigating changes in facility-level prescribing rates (vitamin D, calcium, osteoporosis medications) before and after its implementation (2007 versus 2012). The second study was a pilot cluster randomized trial evaluating the feasibility and effectiveness of a 12-month, multifaceted, interdisciplinary KT intervention [Vitamin D and Osteoporosis Study (ViDOS)]. Prescribing outcomes included: vitamin D ≥800 IU (primary), calcium ≥500 mg/day, and osteoporosis medications (high-risk residents only). Feasibility outcomes included recruitment, retention, data collection, intervention fidelity, and process changes. We analyzed resident level data using the generalized estimating equations (GEE) technique, adjusting for clustering.</p> <p><strong>Results:</strong></p> <p>In both studies, significant improvements were observed for vitamin D and calcium prescribing. In the first study, prescribing increased by 38% and 4%, respectively, between 2007 and 2012. In the ViDOS trial, the 12-month intervention resulted in an absolute improvement of 15% and 7%, respectively (intention to treat cohort). There was no significant effect for prescribing of osteoporosis medications in either study. In the ViDOS study, recruitment and retention rates were 22% and 63%, respectively; good intervention fidelity was achieved and intervention homes reported several process changes.</p> <p><strong>Conclusion:</strong></p> <p>This thesis study demonstrated that KT interventions targeting evidence-based osteoporosis and fracture prevention strategies were feasibly and effectively applied with interdisciplinary LTC teams.</p> / Doctor of Philosophy (PhD)

Long-term repercussions of extremity trauma can include fracture mal- and non-union, osteoarthritis, pain, and impairment of physical movement, which can result in disuse of the limb and eventual bone loss. Although trauma is commonly investigated in palaeopathology, the functional repercussions of injuries are not typically considered. By integrating palaeopathological fracture analyses and biomechanical investigations of cross-sectional properties, this thesis explores individual and group experiences of extremity fracture risks, responses, and consequences at two Roman sites. Adults from 1st-4th century AD Roman cemeteries at Ancaster, UK (n=181), and Vagnari, Italy (n=66), were examined for limb fractures. Data on fracture type, location, malunion, and associated infection and osteoarthritis were collected. Bone areas and asymmetries were calculated using biplanar radiographs for individuals without fractures, and compared to those of individuals with fractures. Patterns in bone amounts and asymmetries associated with fracture attributes were identified. Extremity fractures were observed in 39 individuals from Ancaster and 12 individuals from Vagnari, but the prevalence rates did not differ between the sites. Cross-sectional properties suggested that compared to Ancaster, individuals living at Vagnari experienced greater mechanical loading (i.e., larger bone areas). Disuse of a fractured limb was only identified in two old adult individuals from Ancaster; no Vagnari individuals had evidence for post-traumatic dysfunction. Functional consequences of injuries were not associated with observable fracture attributes (e.g., fracture type, malunion), meaning that physical impairment cannot be recognized based only on an injury’s appearance. By incorporating biomechanical methods in palaeopathological analyses of trauma, this thesis reveals the physical experiences of injury acquisition and recovery among residents of Ancaster and Vagnari over the life course. The relative absence of post-traumatic disuse speaks to the resilience of Romans at these sites, and contributes to the growing literature on the human experience of trauma and impairment in the past. / Thesis / Doctor of Philosophy (PhD) / Immobility and disuse of a fractured arm or leg can result in bone loss. Using radiographs, this research evaluated physical activity and long-term fracture complications in adult skeletons from ancient Roman communities at Ancaster, UK and Vagnari, Italy (1st-4th century AD). Compared to Ancaster, Vagnari individuals had thicker bones that indicated they were more physically active. Evidence for physical consequences were not associated with the type or location of a fracture; only two individuals from Ancaster (and none from Vagnari) had evidence of disuse. This study of fracture consequences contributes to our understanding of injury risk and recovery in the past. Although fractures can cause lasting physical consequences, these results show that fractures that appeared ‘severe’ did not necessarily result in long-term impairment. Most residents at Ancaster and Vagnari were physically active and recovered from their injuries, a finding that emphasizes the importance of continued physical activity after injury.

Fracture systems or networks always control the stability, deformability, fluid and gas storage capacity and permeability, and other mechanical and hydraulic behavior of rock masses. The characterization of fracture systems is of great significance for understanding and analyzing the impact of fractures to rock mass behavior. Fracture trace data have long been used by engineers and geologists to character fracture system. For subsurface fractures, however, boreholes, wells, tunnels and other cylindrical samplings of fractures often provide high quality fracture trace data and have not been sufficiently utilized. The research work presented herein is intended to interpret fracture traces on borehole walls and other cylindrical surfaces by using stereology. The relationships between the three-dimension fracture intensity measure, P32, and the lower dimension fracture intensity measures are studied. The analytical results show that the conversion factor between the three-dimension fracture intensity measure and the two-dimension intensity measure on borehole surface is not dependent on fracture size, shape or circular cylinder radius, but is related to the orientation of the cylinder and the orientation distribution of fractures weight by area. The conversion factor between the two intensity measures is determined to be in the range of [1.0, &#960;/2]. The conversion factors are also discussed when sampling in constant sized or unbounded fractures with orientation of Fisher distribution. At last, the author proposed estimators for mean fracture size (length and width) with borehole/shaft samplings in sedimentary rocks based on a probabilistic model. The estimators and the intensity conversion factors are tested and have got satisfactory results by Monte Carlo simulations. / Ph. D.

Yes / More than 2 million people/year suffer a bone fracture in the UK1. Reconstruction of bone defects represents a major clinical challenge and is addressed using a number of medical devices. Although medical device compositions and applications may differ widely, all attract microorganisms and represent niches for medical device associated infections. For open fractures, the risk of infection can be 55%2. These infections are often resistant to many of the currently available antibiotics and represent a huge and growing financial and healthcare burden. The aim of this study was a fundamental understanding of how the presence of host defence peptides (HDPs)3 and/or RGD can influence the outcome of cell vs. bacterial viability and proliferation. / Presented at the conference: eCM XVI - Bone and Implant Infection June 24-26, 2015, Convention Centre, Davos Platz, Switzerland.