The Shared Contributions Of The Capsule, Labrum, And Bone On The Suction Seal Of The Hip, Alexander J. Hoffer

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The hip capsule, labrum, and bone contribute to hip stability. Abnormalities in these structures are associated with pain and microinstability. Previous studies have quantified the individual stabilizing roles of the capsule and labrum and have associated cam over-resection with decreased hip stability.

The first objective of this thesis was to identify the relative biomechanical contributions of the capsule, labrum, and bone to the hip suction seal, as a representation of hip stability. The second objective was to assess the effectiveness of a labral reconstruction in restoring the suction seal after a cam over-resection.

Ten human cadaveric hips were tested in …

Evaluation Of Conservative And Operative Treatments In Active Patients With Acromioclavicular (Ac) And Rotator Cuff (Rc) Injuries, Jesse Singh

Electronic Thesis and Dissertation Repository

Abstract

Introduction: Shoulder pain and disability, particularly acromioclavicular joint (ACJ) and rotator cuff (RC) injuries, are common in a physically active population. Determining operative or rehabilitative treatment plans involve multiple treatment choices influenced by the injury grade and treatment goals, such as return to sport. This thesis investigates the management of treatment for AC and RC injuries

Method: The first study is a scoping review that uses the Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for Scoping Reviews (PRISMA-ScR) to synthesize 32 studies involving athletes who have undergone conservative or operative treatment for their Rockwood grade III …

Pannexin3 In Exercise, Obesity, And Osteoarthritis, Brent Wakefield

Electronic Thesis and Dissertation Repository

Pannexin 3 (PANX3), is a glycoprotein that oligomerizes to form mechano-sensitive channels expressed in musculoskeletal tissues, and has been identified as a potential target for the treatment of obesity and osteoarthritis (OA). Obesity and OA are two of the most prevalent diseases worldwide, leading to disability and even death. These conditions are thought to originate from a complex interaction between genetics, aging, sex, and modifiable lifestyle factors, such as exercise. Investigating the interactions between genetic and exercise may provide a more comprehensive, context-specific understanding of gene function. This thesis aimed to understand the interactions between PANX3 and exercise interventions on …

Plantar Flexor Dynamic Contractile Rates Are Not Dependent On Calcaneal Tendon Stiffness, Sohum Kulkarni

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The ability to rapidly generate muscular torque and velocity is important in specialized activities and daily tasks of living. Tendon stiffness is one factor in the neuromuscular system that influences musculoskeletal torque transmission. Previous studies have reported weak-to-moderate correlations between tendon stiffness and rate of torque development (RTD). However, these correlations have been reported only for isometric contractions which may not be relevant to contractions involving joint rotation (i.e., dynamic). The purpose was to investigate the effect of calcaneal tendon stiffness on the dynamic rates of torque (RTD) and velocity (RVD) development in plantar flexor muscles. Young adult males (n=13) …

Novel 129xe Magnetic Resonance Imaging And Spectroscopy Measurements Of Pulmonary Gas-Exchange, Alexander M. Matheson

Electronic Thesis and Dissertation Repository

Gas-exchange is the primary function of the lungs and involves removing carbon dioxide from the body and exchanging it within the alveoli for inhaled oxygen. Several different pulmonary, cardiac and cardiovascular abnormalities have negative effects on pulmonary gas-exchange. Unfortunately, clinical tests do not always pinpoint the problem; sensitive and specific measurements are needed to probe the individual components participating in gas-exchange for a better understanding of pathophysiology, disease progression and response to therapy.

In vivo Xenon-129 gas-exchange magnetic resonance imaging (¹²⁹Xe gas-exchange MRI) has the potential to overcome these challenges. When participants inhale hyperpolarized ¹²⁹Xe gas, it …

Vertebral Endplate Structural Defects: Measurement, Prevalence And Associated Factors, Aliyu Lawan

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Objective: To synthesize current knowledge on the association of endplate structural defects (EPSD) with back pain (BP), improve EPSD measurement, and investigate EPSD prevalence, distribution, and association with age and body mass index (BMI).

Methods: In study 1, a systematic review was conducted on five databases for studies reporting on the association between EPSD and BP. Studies 2 and 3 used CTs and mCTs of 19 embalmed cadavers to examine the diagnostic accuracy of common EPSD assessment methods, and to develop and validate a novel method. Study 4 used the novel method on 200 adult males’ MRI to estimate EPSD …

The Clinical Value Of Oculomotor Assessments Across The Continuum Of Concussion, Dillon Richards

Electronic Thesis and Dissertation Repository

Concussions are complex conditions that are difficult to manage medically. Variations in symptom presentation, intricate neurophysiological processes, and the availability of a variety of possible assessment tools may contribute to this complexity. Clinicians must use a broad approach, employing both subjective symptom assessment and objective assessments to confirm a diagnosis and/or monitor progression and recovery. Oculomotor function after concussion may be an important indicator of injury, given the interconnectedness of oculomotor function, vestibulo-ocular and visual systems, and even cognition. Oculomotor function may be assessed objectively or indirectly using patient-reported symptom checklists as part of subjective assessments. One way of objectively …

Role Of Decorin At The Fetal-Maternal Interface, Chidambra D. Halari

Electronic Thesis and Dissertation Repository

The human placenta is an invasive tumor-like structure, this invasion being physiological. A subset of placental trophoblast called extra-villous trophoblast invades the uterine decidua and remodels uterine arteries into low-resistance, high-flow tubes to permit adequate flow of maternal blood to nourish the fetus. A poor extra-villous trophoblast invasion and uterine arterial remodeling can lead to fetal growth restriction and a serious pregnancy-associated maternal disease preeclampsia. Decorin, a leucine-rich proteoglycan produced by uterine decidual cells restrains multiple trophoblast functions: self-renewal and differentiation of trophoblast stem cells, migration, invasion, proliferation and endovascular differentiation. Additionally, decidual overproduction of decorin was associated with preeclampsia, …

The Design And Evaluation Of A Subacromial Implant In Restoring Normal Glenohumeral Joint Stability In The Presence Of A Massive Irreparable Rotator Cuff Tear, Cole T. Fleet

Electronic Thesis and Dissertation Repository

Massive irreparable rotator cuff tears are a common cause of pain and disability. Several different treatment options are available for this pathology; however, these treatments have been associated with poor clinical outcomes when used to treat younger (<65 years), more active patients. The purpose of this thesis was to design and evaluate a subacromial implant in its ability to restore normal glenohumeral stability and range of motion. The implant was created as a modular device, which captured different implant thicknesses (5mm and 8mm) and constraints (high and low) within its design. In-vitro testing compared the ability of these implants to restore normal shoulder biomechanics. The results indicated the 5mm high constraint implant to be the most effective in restoring normal joint position. Furthermore, range of motion increased when the implant was paired with a tuberoplasty procedure. These results suggest this implant may be advantageous in treating younger patients.

Automation Through Deep-Learning To Quantify Ventilation Defects In Lungs From High-Resolution Isotropic Hyperpolarized 129xe Magnetic Resonance Imaging, Tuneesh Kaur Ranota

Electronic Thesis and Dissertation Repository

Obstructive lung diseases are characterized by heterogenous ventilation. Hyperpolarized ¹²⁹Xe gas lung magnetic resonance imaging (MRI) can examine lung ventilation heterogeneity by acquiring high-resolution isotropic images. The current gold standard of semi-automated (SA) segmentation can be used to quantify non-isotropic ¹²⁹Xe lung images to generate ventilation defect percent (VDP), however, this method is not suitable for analysis of isotropic voxel ¹²⁹Xe images due to the large number of slices. Therefore, we used a fully automated deep learning-based (DL) lung algorithm to calculate VDP from isotropic images. SNR, SA and DL-based VDP were calculated, showing a strong positive …

Role Of The Epithelial-To-Mesenchymal Transition (Emt) On Circulating Tumor Cell (Ctc) And Metastasis Biology In Prostate Cancer, Jenna M. Kitz

Electronic Thesis and Dissertation Repository

Prostate cancer is the second leading cause of cancer-related deaths in American men. Most of these deaths occur as the result of metastasis, which is associated with an epithelial-to-mesenchymal transition (EMT). EMT leads to greater migratory/invasive capacity and resistance to therapy. During metastasis and associated EMT, cancer cells shed from the primary tumor and disseminate throughout the body as circulating tumor cells (CTCs) in the bloodstream. CTCs have been correlated with increased metastatic disease, reduced survival, and therapy response/resistance. Assessing CTCs presents an opportunity to study cancer progression/treatment effectiveness from a blood test. However, outstanding questions regarding CTCs and EMT …

Connexin 43 Contributes To Phenotypic Variability Of The Mouse Skull, Elizabeth Jewlal

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The purpose of this study was to determine whether connexin 43 (Cx43) contributes to craniofacial phenotypic variability. Skull shape and variation were compared within and among two heterozygous mutant mouse models (G60S/+ and I130T/+) that exhibit different levels of Cx43 channel function when compared to their wildtype counterparts (~80% and ~50% reduction in function, respectively). Results indicated mutants have significant differences in skull shape compared to wildtype littermates. Similar patterns of shape difference were found in both mutants. Increased skull shape variation and a disruption in the covariation of skull structures were observed in G60S/+ mutants only. These results show …

Femoroacetabular Impingement Syndrome: Evaluating Postoperative Rehabilitation Progress And Return To Sport Readiness, Trevor A. Day

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Femoroacetabular impingement syndrome (FAIS) is a common cause of non-arthritic hip pain and reduced physical activity in active young adults. It is defined as a motion-related disorder of the hip with a triad of symptoms, clinical signs, and imaging findings that represents symptomatic premature contact between the proximal femur and the acetabulum. There are two anatomical morphologies that can cause FAIS, cam, and pincer, and is a challenging clinical pathology. Patients typically undergo hip arthroscopy to repair damage to the joint and recess the bone causing the impingement. These procedures can result in positive outcomes for the patient, like reduced …

Establishing Intratumoral Modulation Therapy As A New Treatment Modality For High Grade Gliomas, Andrew M.A. Deweyert

Electronic Thesis and Dissertation Repository

Glioblastoma (GBM) is the most common and lethal primary brain cancer in adults despite aggressive treatments with surgery and chemo-radiation. Advances in electrotherapeutics offer a foundation for developing new treatment modalities that exploit an innate vulnerability of glioblastoma (GBM). Low intensity, non-ablative electric fields are innocuous to normal neural structure, but incite GBM cell apoptosis by putatively disrupting cytokinesis and transmembrane ion homeostasis. Our collaborative research group is pioneering a new electrotherapeutic technology for GBM called Intratumoral Modulation Therapy (IMT) which uses customized, implanted bioelectrodes to deliver sustained, titratable and focused therapeutic electric fields into tumor-affected brain regions. My work …

Novel Imaging Tools Reveal The Dynamics Of The Myocardial Growth Hormone Secretagogue Receptor In Heart Disease And Heart Failure, Rebecca Sullivan

Electronic Thesis and Dissertation Repository

Heart disease (HD) is the leading cause of mortality worldwide. Currently, diagnosis is based on clinical features, imaging, and circulating cardiac biomarkers. Cardiac imaging technologies, such as echocardiography and cardiac magnetic resonance imaging (cMRI), enable the non-invasive detection of changes in heart function. Although these modalities can detect changes in structure and anatomy, it is usually at later stages, where prevention may not be possible. In conjunction with imaging, circulating biomarkers of heart failure (HF), notably B-type natriuretic peptide (BNP) and cardiac troponin I and T, can be detected with increased levels in the blood. These biomarkers are associated with …

The Role Of Gsk3 Alpha And Beta In Embryonic Craniofacial Development, Harman Jassar

Electronic Thesis and Dissertation Repository

Background: The GSK-3 genes (Gsk3a and Gsk3b) have been known to affect many cellular processes and signaling pathways some of which are implicated in the growth and development of the craniofacial skeleton.

Aim: The purpose of this study was to assess the effect of chondrocyte-specific deletion of Gsk3a and Gsk3b on the size of the mandible and craniofacial skeleton in embryonic mice.

Materials & Methods: Mice were bred to generate cartilage-specific Gsk3a and Gsk3b KO mice. On embryonic day 18.5 (E18.5) the offspring were gathered by caesarian section. Whole mount skeletal staining was completed on the specimens using …

Assessment Of Landing Biomechanics And Rehabilitation After Anterior Cruciate Ligament Reconstruction, Sheila S. Gagnon

Electronic Thesis and Dissertation Repository

Aberrant landing biomechanics increase the risk of anterior cruciate ligament (ACL) injury and are a focus of rehabilitation after ACL reconstruction. The purpose of the present thesis was to develop and evaluate methods of assessing landing mechanics and investigate the effects of different rehabilitation strategies after ACL reconstruction. Three studies were conducted. The first study used a Delphi process to develop the content of a Clinician-Rated Drop Vertical Jump Scale to evaluate jump landing mechanics during rehabilitation after ACL reconstruction. Twenty experts participated in four rounds of questioning, resulting in 92% agreement for knee valgus collapse, lateral trunk lean, insufficient …

An Investigation On The Influences Of Radial Head Hemiarthroplasty Stem Fixation Techniques On Articular Mechanics, Jakub Szmit

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Radial head hemiarthroplasty design has been extensively studied with a focus on utilizing the geometrical characteristics of the native radial dish as a guide of implant placement and design. Although implant design has been studied, optimal radial head implant fixation technique remains unknown. This thesis focused on the effect of stem fit on radiocapitellar contact mechanics, using both finite element and experimental bench-top approaches. Additionally, investigation into the impact of varus/valgus malalignment of the radial head in both the native state and following hemiarthroplasty was conducted. It was found that loose fitting a smooth stem axisymmetric radial head implant through …

Implementing A Multi-Segment Foot Model In A Clinical Setting To Measure Inter-Segmental Joint Motions, Tahereh Amiri

Electronic Thesis and Dissertation Repository

It has been illustrated that measuring inter-segmental joint motions of the foot using a dynamic method is required to evaluate the function and level of impairment of the foot joints. Optical motion tracking using the multi-segment foot model (MSFM) developed by Jenkyn and Nicole (2007), has been demonstrated to be a valid tool for measuring the motion of the joints within the foot. However, in current practice, inter-segmental joint motions of this model are measured using a custom-written software (MATLAB) and it limits the clinical usefulness of this model. Hence, this study implemented the MSFM introduced by Jenkyn and Nicole …

Quadriceps Muscle Layer Thickness In Kidney Transplant Recipients: A Potential Measure Of Frailty And Sarcopenia, Max A. Levine

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Introduction: Frailty and sarcopenia are related concepts that can impact outcomes after kidney transplantation. Measures of these two entities and new/emerging metrics of sarcopenia remain to be validated.

Methods: In a prospective cohort study, kidney and kidney-pancreas transplant recipients were assessed at the time of transplant with the Physical Frailty Phenotype, bioimpedance analysis, quadriceps muscle layer thickness (QMLT), and CT. The impact on length of stay (LOS), prediction of frailty/sarcopenia, and relative concordance of metrics were analyzed.

Results: Low QMLT, a putative surrogate of sarcopenia/frailty, was more frequently associated with longer LOS (>14 days) after transplant. Additionally, QMLT was …

The Of Application Of 3d-Printing To Lumbar Spine Surgery, Andrew J. Kanawati

Electronic Thesis and Dissertation Repository

Rapid prototyping refers to the manufacturing process in which a three-dimensional (3D) digital model can be transformed into a physical model by layering material in the shape of successive cross sections atop of previously layers. Rapid prototyping has been increasing in popularity in the field of medicine and surgery due to the ability to personalize various aspects of patient care. The thesis will explore the use of rapid prototyping in lumbar spine surgery, aim to quantify the accuracy of medical imaging when relating to imaged structures and their corresponding models produced by rapid prototyping, and determine if complex patient-specific guides …

Investigating The Role Of Nuclear Receptor Peroxisome Proliferator-Activated Receptor Δ In Obesity-Associated Osteoarthritis, Bethia C. To

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Osteoarthritis (OA) is a heterogeneous disease, differentiated based by risk factors that drive joint damage. Peroxisome proliferator-activated receptor delta (PPARd) is a nuclear receptor previously implicated in cartilage damage in OA. Given its deleterious role in post-traumatic OA and in regulating metabolism, we hypothesized that PPARd inhibition will protect against obesity-associated OA. Diet-induced obesity was used to induce OA in mice. Mice fed the western diet for 40 weeks exhibited mild OA, with subchondral bone remodelling occurring alongside cartilage damage. Cartilage-specific Ppard knockout (KO) mice were generated to study its role in metabolic OA. Both wildtype and PPARd KO mice …

Does An Acute Achilles Tendon Rupture Become A Patient's Achilles Heel In The Long-Term?, Michaela Cm Khan

Electronic Thesis and Dissertation Repository

It is unknown if deficits in the involved limb following acute Achilles tendon rupture (AATR) persist in the long-term, or differ between patients treated operatively or non-operatively. This study investigated 43 patients 15±1 years post-AATR from a previous randomized controlled trial (RCT) that compared operative and non-operative treatment. Structural characteristics in the Achilles tendon and surrounding musculature were assessed using magnetic resonance imaging. We also performed physical examinations and evaluated performance-based and patient-reported outcomes. Overall, there were substantial differences between the involved and uninvolved limbs in most outcomes. Some outcomes improved over time from the initial RCT to the final …

Exploring Current Topics And Trends In Anatomy Education: A Scoping Review, Alex Wolf

Electronic Thesis and Dissertation Repository

Within the field of health professional education, one finds that anatomy often presents students with a great deal of difficulty. The literature in this area is piecemeal and there is limited work available examining the whole of this topic. A scoping review was conducted to determine how students are taught anatomy across multiple disciplines (medicine, dentistry, rehabilitation sciences, and undergraduate education) and to assess for any notable differences between these populations. The results found that scholarship on anatomy instruction varies based on educational context, and medical students are the most frequently targeted student population. It also found that the use …

The Feasibility Of Gathering Patient-Reported Outcome Measures On Individuals With Acute Ankle Sprains In A Busy Clinic Environment, Ryan Reeson

Electronic Thesis and Dissertation Repository

Ankle sprains are the most common sports injury and can lead to long-term deficits. Patient-reported outcome measures (PROMs) may assist clinicians in evaluating the recovery trajectory of patients with ankle sprains. However, before a large-scale study can be performed, it is necessary to determine whether it is feasible to collect PROMs in a busy clinic environment. This study had a narrow recruitment window but the consent rate was 100%. Ten patients at Fowler Kennedy Sport Medicine Clinic were followed for up to six visits. Three PROMs that characterized lower extremity function were measured. The measurement completion rate decreased from 100% …

Ultra-High Field Magnetic Resonance Imaging For Stereotactic Neurosurgery, Jonathan Lau

Electronic Thesis and Dissertation Repository

Stereotactic neurosurgery is a subspecialty within neurosurgery concerned with accurate targeting of brain structures. Deep brain stimulation (DBS) is a specific type of stereotaxy in which electrodes are implanted in deep brain structures. It has proven therapeutic efficacy in Parkinson’s disease and Essential Tremor, but with an expanding number of indications under evaluation including Alzheimer’s disease, depression, epilepsy, and obesity, many more Canadians with chronic health conditions may benefit. Accurate surgical targeting is crucial with millimeter deviations resulting in unwanted side effects including muscle contractions, or worse, vessel injury. Lack of adequate visualization of surgical targets with conventional lower field …

Improving Material Mapping In Glenohumeral Finite Element Models: A Multi-Level Evaluation, Nikolas K. Knowles

Electronic Thesis and Dissertation Repository

An improved understanding of glenohumeral bone mechanics can be elucidated using computational models derived from computed tomography data. Although computational tools, such as finite element analysis, provide a powerful quantitative technique to evaluate and answer a variety of biomechanical and clinical questions, glenohumeral finite element models (FEMs) have not kept pace with improvements in modeling techniques or model validation methods seen in other anatomic locations. The present work describes the use of multi-level computational modeling to compare, develop and validate FEMs of the glenohumeral joint.

Common density-modulus relationships within the literature were evaluated using a multi-level comparative testing methodology to …

Acromial Insufficiency Fractures In Reverse Total Shoulder Arthroplasty: A Biomechanical Study, Alicia Kerrigan

Electronic Thesis and Dissertation Repository

Reverse total shoulder arthroplasty (RTSA) is increasingly utilized in the aging population, with a growing list of surgical indications including rotator cuff tear arthropathy, proximal humerus fractures, and revision arthroplasty. Acromial insufficiency fractures following RTSA are poorly understood, difficult to diagnose, and associated with inferior clinical outcomes. There is limited knowledge in the literature regarding the etiology of post-operative acromial fractures. The purpose of this study is to evaluate the role of implant parameters on acromial strain following RTSA.

Using a cadaveric model, a custom designed modular RTSA system was implanted that allowed for evaluation of modifiable parameters including glenoid …

Tibiotalar Arthrodesis: Development Of A Novel Jig And Alignment Guide, Adam Mathew Ropchan

Electronic Thesis and Dissertation Repository

Tibiotalar arthrodesis is a surgical procedure, used for the treatment of end-stage ankle arthrosis and instability. There are dozens of described procedures in the literature, all with varying rates of success. Two of the most common reasons for reoperation in tibiotalar arthrodesis are nonunion and infection; few studies have established any associations between patient/surgical factors and reoperation for nonunion and infection.

The first part of this thesis focuses on determining the rate of reoperation to the ipsilateral lower limb and if any patient/surgical factors are associated with reoperation for nonunion and infection. The second part of this thesis turns attention …

The Use Of Current Steering During Subthalamic Deep Brain Stimulation To Alleviate Upper Limb Symptoms Of Parkinson's Disease, Shabna Iftikar Mohideen

Electronic Thesis and Dissertation Repository

Subthalamic (STN) deep brain stimulation (DBS) is an established treatment to alleviate the appendicular motor symptoms of Parkinson's Disease (PD). Current steering during DBS allows the unequal fractionation of current between two electrodes on the lead, resulting in a non-spherical electrical field. It is hypothesized that the way the electrical field is shaped will affect a patient’s upper limb symptom alleviation. Seven PD patients who underwent bilateral STN-DBS were tested over four weeks post-operation. 16 current fractionation settings were tested each week at an amplitude that increased weekly. Optimal setting was defined as the setting that provided the best …