Browsing by Author "Ronsky, Janet L."
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- ItemOpen AccessA 3D in-situ model for patellofemoral joint contact analysis in the normal and anterior cruciate ligament deficient knee(1997) Boyd, Steven Kyle; Ronsky, Janet L.
- ItemOpen AccessA Comparison of Biomechanical Outcomes in Single Leg Squat and Vertical Drop Jump in Youth and Young Adults with and without a Previous Youth Sport-Related Knee Joint Injury(2018-04-30) Lorenzen, Kristin Nicole; Emery, Carolyn; Ronsky, Janet L.; Whittaker, Jackie L.; Edwards, William Brent; Bertram, John E.Objective: To examine the kinematic and kinetic differences during functional movements between youth and young adults with a history of intra-articular knee injury and age, sex, and sport matched controls. Methods: In total, 186 youth/young adults (age 15-26; 100 female, 86 male; 93 matched pairs) attended a testing session in which kinematic and kinetic data were collected using a motion capture camera system and two force platforms. Joint angles and moments for the ankle, knee, hip, and trunk were calculated and between-group differences were analyzed. Results: No group differences were observed for either males or females in the primary outcomes (knee abduction/adduction angle, knee abduction/adduction moment) in either the vertical drop jump or single leg squat. Group differences were observed for the females during the vertical drop jump in the hip abduction moment on the index limb and the knee valgus angle, knee abduction moment, and hip external rotation angle on the non-index limb; during the single leg squat in the hip adduction angle on the index limb and the knee flexion angle on the non-index limb. Conclusions: Previously injured female participants demonstrate some kinematic and kinetic differences in functional movements 3-10 years following an intra-articular knee joint injury.
- ItemOpen AccessA Novel Measure of In-Vivo Knee Joint Laxity(2008) Küpper, Jessica; Ronsky, Janet L.
- ItemOpen AccessAssessment of 3d reconstruction of scoliotic human torso using optical imaging techniques(2007) Robu, Daniela; Ronsky, Janet L.; Cheriet, Farida
- ItemOpen AccessAutomatic quantification of osteoarthritis features in MRI using deep learning methods(2023-03-20) Felfeliyan, Banafshe; Ronsky, Janet L.; Jaremko, Jacob L.; Lebel, Marc R.; Li, Matthew D.; Wong, Andy K.; Far, Behrouz; Forkert, Nils D.Osteoarthritis (OA) is a progressive irreversible disease that affects the whole joint involving various tissues including cartilage, bone, and synovium. Accurate OA diagnosis and management requires a thorough understanding of its pathogenesis, along with precise monitoring of its trajectories and changes associated with treatment. Magnetic resonance imaging (MRI) is an excellent tool for understanding OA progression and diagnosis. However, its assessment relies on reader-dependent semiquantitative scores, which are subjective, laborious, and insensitive to small changes. An automated OA assessment pipeline using deep learning (DL) can overcome limitations but faces challenges, including low generalizability, label scarcity, and noisy clinical labels with high variability. Therefore, this thesis’s objective is to overcome challenges associated with automated OA assessment by developing DL methods for the quantitative assessment of predominant OA biomarkers (cartilage, effusion-synovitis, and bone marrow lesion (BML)). This thesis proposed ImprovedMaskRCNN (iMaskRCNN), an accurate DL algorithm for multiscale segmentation of tissues involved in OA (femur, tibia, femoral and tibial cartilages, and hip effusion), which improves Dice score by 1-7%. Algorithm outputs are used to quantify cartilage thickness and hip effusion volume. An unsupervised domain adaptation pipeline using iMaskRCNN and CycleGAN was proposed to overcome DL’s low generalizability across MRI sequences. Therefore, a weakly supervised training strategy was proposed for BML segmentation, using soft labels obtained from clinical scoring and a noise-robust loss, which increased the Dice score and recall by 8% and 22%, respectively. Effusion segmentation was achieved using a self-supervised learning approach to pretrain the iMaskRCNN algorithm for training with a few-labeled dataset and improved the Dice by more than 8%. Following validation of the developed methods, results were compared with patient outcomes indicating strong associations of the extracted BML and effusion features (Δpain vs. ΔDL-effusion r =0.59, and Δpain vs. Δtibial BML r=0.49). This research provides an efficient integrated tool for quantifying OA features from MRI to accurately monitor OA progression and structural changes. This tool enables large population analyses and the extraction of more sensitive measures for clinicians to understand OA. The proposed methods have strong potential to apply to other joints, tissues, and medical image analysis problems.
- ItemOpen AccessBiomechanical assessment following gender-specific female total knee replacement(2010) Samaan, Cynthia Dawn; Ronsky, Janet L.
- ItemOpen AccessBiomechanical assessment of CAD/CAM and hand-cast prostheses for transtibial amputees(2009) Thannhauser, Steven Victor; Ronsky, Janet L.
- ItemOpen AccessBiomechanics of occupant loading by pre-crash motorized shoulder belt tensioning(2007) Good, Craig Andrew; Ronsky, Janet L.; Viano, David C.
- ItemOpen AccessDetermining the cause of motor-vehicle related paediatric bicycling injuries(2018-07-18) Pitt, Tona Michael Chase; Hagel, Brent Edward; McCormack, Gavin R.; Nettel-Aguirre, Alberto; Howard, Andrew W.; Ronsky, Janet L.Despite health benefits, bicycling as a form of active transportation has declined. Bicycle-motor vehicle collisions (BMVCs) pose a risk for severe injury to youth and are a leading deterrent to youth bicycling. This thesis aims to identify characteristics of BMVCs. Divided roads with no barrier, signage presence and peak traffic times had lower odds of severe injury in youth after BMVC. We adapted a culpability tool to Alberta police collision report data and used this tool to define a control group of drivers from collisions involving only motor vehicles. These controls were compared with drivers in BMVCs. Drivers older than 54 years had higher odds of youth BMVC, light trucks/vans had lower odds and driving between18:01hrs-24:00hrs had the highest odds of BMVC. It is possible to adapt culpability tools to other jurisdictions and can be used to address the often-neglected role of the driver in youth BMVCs.
- ItemOpen AccessDevelopment and validation of an experimental technique for studying dynamic stability during standing(2003) Gildenhuys, Anne; Ronsky, Janet L.; Zernicke, Ronald F.
- ItemOpen AccessDevelopment of bioabsorbable braided vascular scaffolds for the intracranial circulation(2019-05-29) Jamshidi, Mehdi; Mitha, Alim Pyarali A.; Sundararaj, Uttandaraman; Ronsky, Janet L.; Di Martino, Elena S.An intracranial (or brain) aneurysm is a life-threatening disease that affects more than 3% of the population. The treatment techniques of cerebral aneurysms have significantly improved in the past decade, transitioning from open surgical procedures to less invasive endovascular procedures. A disruptive technology in aneurysm treatment was the advent of the metal flow-diverting stent, which made it relatively easy to treat the most complicated of brain aneurysms, and avoiding the need for a high-risk open surgical procedure. Despite these improvements, metal stents are still associated with major complications, mostly due to their thrombogenicity as well as their long-term implications. Although the need for a stent to treat aneurysms is only temporary, due to progressive neointima formation over the stent structure, they cannot be removed. This requires patients to remain on lifelong anti-platelet medications, which can cause other health problems. Bioabsorbable stents have been postulated as a way to overcome the long-term disadvantages of metal stents. Commercial bioabsorbable stents have been developed for coronary artery diseases, although the design of coronary stents is different than for intracranial aneurysms. Coronary stents are mostly balloon expandable, and can acquire good wall apposition simply by balloon inflation. Stents used for intracranial applications, on the other hand, are required to be flexible and self-expandable, and they should revert to at least close to their original diameter after deployment from the catheter. The challenges for the design of bioabsorbable flow-diverting stents for the treatment of intracranial aneurysms lies in differences with the deployment mechanism, the poor mechanical properties of bioabsorbable polymers, and their inability to show shape memory behavior. In this study, we designed and fabricated bioabsorbable flow-diverting stents for the treatment of aneurysms. Information acquired from existing stents, as well as the three initial iterations of our design, are reviewed and discussed. The mechanical properties and safety profile of our stents were studied in vitro, and the safety and efficacy were also studied in vivo with pilot animal experiments. The bioabsorbable flow-diverting stent that we developed demonstrated mechanical properties similar to existing intracranial stents. They further showed low potential for hemolysis and thrombus formation on the stent struts, as well as neointimal layer formation and persistent side branch patency in animal models at 1 month follow-up. The performance of the stent in terms of flow-diverting capabilities was also demonstrated in acute small and large animal models of intracranial aneurysms.
- ItemOpen AccessDynamic In-Vivo Knee Cartilage Contact With Aging(2020-07-27) Kupper, Jessica C.; Ronsky, Janet L.; Boyd, Steven K.; Lichti, Derek; Edwards, W. Brent; Rainbow, MichaelJoint contact mechanics are important to the study of cartilage health and disease. Risk factors such as aging are speculated to result in altered cartilage contact locations, magnitudes, and sliding velocities, leading to altered loading of typical cartilage contact and non-contact areas. Altered contact patterns are speculated to be an influential mechanism associated with osteoarthritis-related cartilage changes such as softening, stiffening, or swelling. It is unknown whether knee joint contact patterns differ in an asymptomatic aging population compared to their younger counterparts.This feasibility study aimed to enhance understanding of relations amongst contact mechanics, cartilage health, and functional status and aging. This work applied high-speed biplanar videoradiography and magnetic resonance imaging to non-invasively measure a weighted centroid (WC) of tibiofemoral cartilage contact during gait in participants between the ages of 20-30 years (n = 5), and 50-60 years (n = 5). Cartilage contact regions during walking were linked to cartilage-health imaging outcomes (i.e., T2 relaxometry).Assessment of techniques for calculating the WC revealed that interval-based weighting factors provided the optimal approach, showing low sensitivity to errors but high sensitivity to clinically relevant changes. In aging vs. younger participants, no significant differences were found in WC location (median difference between heel strike and first force peak of gait cycle: younger 5.21-9.69%, older 2.12-7.44%), sliding distance (at onset of terminal swing: younger 0.50-1.15 mm, older 0.74-1.84 mm), or phase plot slope (change in sliding velocity over the surface of the joint; for swing phase: younger 4.14-14.99 mm/s%, older 6.15-14.47 mm/s%). For the first time, a functional relationship was found between T2 relaxometry and the gait cycle with lower T2 values during stance compared to prior to terminal swing. No differences were detected (younger vs. older) in T2 relaxometry values (medial tibial compartment at first force peak of gait: younger 29.8-43.1 ms, older 31.0-37.6 ms). These findings could not support differences in contact mechanics in older asymptomatic tibiofemoral joints compared to younger joints. Nevertheless, some potentially atypical patterns in older participants provide motivation to better understand linkages amongst aging, contact mechanics and cartilage health status across the cartilage degeneration spectrum.
- ItemOpen AccessEngineering of Gelatin Methacryloyl (GelMA) Hydrogels for Developing Biomimetic Tissue Constructs(2020-10-14) Janmaleki, Mohsen; Sanati Nezhad, Amir; Ungrin, Mark D.; Yipp, Bryan G.; Ronsky, Janet L.; Gaharwar, Akhilesh K.; Khoshnazar, Rahil; Lu, Qingye G.Three-dimensional (3D) cell culture offers a more physiologically-relevant context for disease modeling and drug screening. Hydrogel-based biomaterials support the long-term culture of cells in 3D and enhance memetic cell-cell and cell-matrix interactions. Herein, gelatin methacryloyl (GelMA) hydrogel, a well-known photo-crosslinkable hydrogel, was selected for engineering of different tissue constructs.First, the practicability of imprinting cell topography on GelMA hydrogel was investigated. A novel method was developed to fabricate cell-like niches over the hydrogel’s substrate, and its effects on cytocompatibility and drug susceptibility of breast cancer cells were studied. Second, GelMA hydrogel was tuned in terms of mechanical properties and porosity to facilitate in vitro myelination of dorsal root ganglia (DRG) neurons by Schwann cells (SCs). It was shown that the tuned GelMA enhanced single axonal generation (unlike collagen) and promoted DRGs’ interaction with SCs (unlike PDL). Third, the role of temperature on bioprintability of GelMA bioinks in a two-step crosslinking strategy was investigated. Lowering the temperature can enhance the physical gelation of GelMA and consequently improve filament formation. Results showed that the decrease in the temperature could improve the printability and shape fidelity of the deposited hydrogel, particularly at 15 °C. Time-dependent mechanical testing confirmed higher elastic properties of the collected hydrogel at the lower temperature.Fourth, a hydrogel-based 3D human intracranial aneurysm (IA) model was developed using liquid assisted injection molding. With clinically relevant dimensions and tuned fluidic and matrix properties, the essential endothelium was successfully lined inside the reconstructed IA over pre-cultured smooth muscle cells. Based on the characterized viscoelastic properties of the GelMA hydrogel and with the help of a fluid-structure interaction model, the capability of the IA construct model in predicting the response of the IA to different fluid flow profiles was demonstrated.Finally, using the techniques developed in this thesis, a new approach is suggested to fabricate a fully hydrogel-based platform for tissue engineering and organ-a-chip applications.
- ItemOpen AccessEstimating scoliosis progression from three dimensional torso shape(2008) Swanson, Samantha Leigh; Ronsky, Janet L.
- ItemOpen AccessHuman patellofemoral kinematics and related joint surface geometry(1999) Powers, Marilyn Joy; Ronsky, Janet L.
- ItemOpen AccessIn vivo investigation of patellofemoral joint characteristics under loading(2009) Robu, Ion; Ronsky, Janet L.
- ItemOpen AccessIn-vivo characterization of patellar tracking in normal and PFPS(2006) Connolly, Kimberly Dawn; Ronsky, Janet L.
- ItemOpen AccessIn-vivo dynamic joint stability quantified in intact and acl deficient knees(2007) Fjeld, Ingrid Rosalyn; Ronsky, Janet L.
- ItemOpen AccessIn-vivo quantification of patellofemoral joint contact force using a mathematical model(2002) Baker, Sharon Nicole; Ronsky, Janet L.
- ItemOpen AccessKinematics of the head and associated vertebral artery length changes during high-velocity, low-amplitude cervical spine manipulation(2022-06-01) Gorrell, Lindsay M.; Kuntze, Gregor; Ronsky, Janet L.; Carter, Ryan; Symons, Bruce; Triano, John J.; Herzog, WalterAbstract Background Cervical spine manipulation (CSM) is a frequently used treatment for neck pain. Despite its demonstrated efficacy, concerns regarding the potential of stretch damage to vertebral arteries (VA) during CSM remain. The purpose of this study was to quantify the angular displacements of the head relative to the sternum and the associated VA length changes during the thrust phase of CSM. Methods Rotation and lateral flexion CSM procedures were delivered bilaterally from C1 to C7 to three male cadaveric donors (Jan 2016–Dec 2019). For each CSM the force–time profile was recorded using a thin, flexible pressure pad (100–200 Hz), to determine the timing of the thrust. Three dimensional displacements of the head relative to the sternum were recorded using an eight-camera motion analysis system (120–240 Hz) and angular displacements of the head relative to the sternum were computed in Matlab. Positive kinematic values indicate flexion, left lateral flexion, and left rotation. Ipsilateral refers to the same side as the clinician's contact and contralateral, the opposite. Length changes of the VA were recorded using eight piezoelectric ultrasound crystals (260–557 Hz), inserted along the entire vessel. VA length changes were calculated as D = (L1 − L0)/L0, where L0 = length of the whole VA (sum of segmental lengths) or the V3 segment at CSM thrust onset; L1 = whole VA or V3 length at peak force during the CSM thrust. Results Irrespective of the type of CSM, the side or level of CSM application, angular displacements of the head and associated VA length changes during the thrust phase of CSM were small. VA length changes during the thrust phase were largest with ipsilateral rotation CSM (producing contralateral head rotation): [mean ± SD (range)] whole artery [1.3 ± 1.0 (− 0.4 to 3.3%)]; and V3 segment [2.6 ± 3.6 (− 0.4 to 11.6%)]. Conclusions Mean head angular displacements and VA length changes were small during CSM thrusts. Of the four different CSM measured, mean VA length changes were largest during rotation procedures. This suggests that if clinicians wish to limit VA length changes during the thrust phase of CSM, consideration should be given to the type of CSM used.