Browsing by Author "Ronsky, Janet"

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    2D-3D Registration for a High-speed Biplanar Videoradiography Imaging System
    (2022-04) Zhang, Shu; Lichti, Derek; Detchev, Ivan; Ronsky, Janet; Wang, Ruisheng; Armenakis, Costas; Lichti, Derek
    High-Speed Biplanar Videoradiography (HSBV) is an X-ray based imaging system that can derive dynamic bony translations and rotations. The 2D-3D registration process matches a 3D bone model acquired from magnetic resonance imaging (MRI) or computed tomography (CT) scans with the 2D X-ray image pairs. 2D-3D registration is usually conducted in two ways, marker-based and model-based registration. The marker-based method is known for its high registration accuracy thanks to corresponding marker pairs. On the other hand, the model-based method avoids the implantation of radiopaque beads but uses the radiograph’s features, intensities, or gradients to accomplish the data alignment. Two novel marker-based registration methods, the back-projection and the projection methods, were proposed and compared with the state-of-the-art RSA (Roentgen Stereophotogrammetric Analysis) method. A 3D printed bone model with beads was used to validate the proposed methods. The results showed that both methods acquired higher accuracy than the RSA method. In addition, the projection and back-projection techniques can be used for the model-based registration while the RSA method cannot. The projection method was applied to a model-based registration to achieve higher accuracy, providing a 3D reconstruction accuracy of 0.79 mm for both the tibia and femur. By using the non-rigid transformation with a scale factor, this accuracy was successfully increased to 0.56 mm for the tibia and 0.64 mm for the femur. The discrepancies in the 2D-3D registration that led to the non-rigid transformation were validated. It was caused by the offset between the detected edge points in the radiographs and their actual position. A Kalman filter was tested on the marker- and model-based registration results with different random processes and parameters. For marker-based registrations, the standard deviations of the kinematics parameters were improved by 25 – 62% for the translations and 35 – 43% for the rotations. For the model-based registration, these standard deviations were improved by 6 – 38% and 29 – 38%, respectively. While the projection method provided higher accuracy, the back-projection method had the larger capture range for the initialization. An automatic initialization method with 64 starting poses based on the back-projection method was proposed and validated. It successfully eliminated the user intervention in the registration initialization. The improved 2D-3D registration with non-rigid transformation and dynamic estimation allows the determination of accurate 3D kinematic parameters with high efficiency. These kinematic parameters can be used to calculate joint cartilage contact mechanics that provide insight into the mechanical processes and mechanisms of joint degeneration or pathology.
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    The Application of the Reference Finite Helical Axis for Characterizing Knee Joint Kinematics
    (2022-01) Bugajski, Tomasz; Ronsky, Janet; Manske, Sarah; Johnston, Kelly
    Altered knee kinematics are an important biomechanical marker for the development of tibiofemoral osteoarthritis (OA). They are associated with altered cartilage contact areas, resulting in forces acting on unadapted cartilage that may degrade over time. The conventional approach to quantify knee kinematics is with Cardan angles, but the uncommon helical axis (HA) approach may provide supplementary information. However, the HA is susceptible to stochastic errors when angular displacements are small. To alleviate this error, a reference position may be used that permits larger angular displacements. However, more assessments are required to determine the utility of this reference finite helical axis (rFHA) method to provide biomechanical markers of tibiofemoral OA. The purpose of this thesis was to technically evaluate the rFHA and demonstrate its ability to distinguish knee kinematics of high tibiofemoral OA risk individuals. Technical evaluations consisted of 1) determining the effect of different smoothing techniques on rFHA accuracy, 2) assessing the sensitivity of the rFHA to reference position misalignments, and 3) comparing rFHA measures between an optical motion camera system (OMCS) and highspeed biplanar videoradiography system (HSBV). The utility of the rFHA was demonstrated by applying it to high tibiofemoral OA risk populations, specifically anterior cruciate ligament repaired (ACLR) knees and older knees. A spline filter with outlier removal process was the top performing smoothing technique for rFHA accuracy, providing a 72.2-80.1% improvement in rotational speed differences. Substantial differences of the rFHA measures were determined with misaligned reference positions, ranging from 1.17-19.53 mm and 0.77-5.45 deg. rFHA measure differences were also found between the OMCS and HSBV, ranging from 10.19-58.03 mm and 3.39-13.63 deg. Finally, kinematic trends were found in ACLR knees during a vertical drop jump, showing greater magnitudes of rFHA dispersion and helical internal rotation than healthy knees (dispersion: 0.46 deg; helical internal rotation: 2.18 deg). Additionally, significantly different rFHA path lengths were found between older and younger asymptomatic knees during walking (10.60 mm, p = 0.01). These findings demonstrate the utility of the rFHA in biomechanics, providing a supplementary method of characterizing knee kinematics and distinguishing the movement patterns of healthy individuals from tibiofemoral OA prone individuals.
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    Biomechanical Evaluation of the Levitation Knee Brace
    (2023-09-13) Baxter, Ryan Charles John; Ronsky, Janet; Kuo, Arthur; Brandon, Scott; Kuntze, Gregor; Rogers-Bradley, Emily; Charbonneau, Marie
    Osteoarthritis (OA) is a debilitating musculoskeletal disease affecting approximately one-third of the adult Canadian population. The most common location of OA occurring is at the knee. OA can affect all three compartments of the knee joint. Knee braces are commonly prescribed for knee OA to reduce pain and improve user function. The LevitationTM “Tri-Compartment Unloader” knee brace (Spring Loaded Technology) was designed to reduce forces in all three compartments of the knee by lowering quadriceps muscle activity, a predictor of knee joint contact force. The effect of the Levitation brace on tri-compartment joint contact forces has yet to be fully investigated. The research objective of this study was to preliminarily investigate the effect of the Levitation brace in a healthy subject on 3-dimensional (3-D) joint kinematics and kinetics, and muscle activity, using biomechanical and musculoskeletal (MSK) computer modeling assessments during a step-back lunge movement. An experimental pilot study was performed to assess the effect of the Levitation brace on joint kinematics and kinetics using a novel combined motion analysis and High Speed Biplanar Radiography approach. A musculoskeletal modelling approach was developed to analyze the effect of the Levitation brace on tri-compartment contact forces, resultant joint moments, and simulated muscle activations. The experimental study results indicate that the Levitation brace did not impact knee joint angles between bracing conditions. The brace reduced knee abduction/adduction and internal/external rotation moments when compared to the unbraced condition. The brace’s impact on flexion/extension moments was unclear. The MSK modelling results predict that the Levitation brace reduced peak contact forces in each of the knee compartments when compared to the unbraced condition. The brace increased quadriceps muscle activation and peak knee extension moments compared to the unbraced condition, contrary to what was expected. Together, the experimental and musculoskeletal modelling results provide a 3-D evaluation of the effect of the Levitation brace on tri-compartment knee joint dynamics which can be used to provide further understanding of the brace design efficacy for OA treatment, and can be applied to improve brace product design and provide insights for future product developments.
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    Bracing of Pectus Carinatum: A Quantitative Analysis
    (2017) Bugajski, Tomasz; Ronsky, Janet; Murari, Kartikeya; Lopushinsky, Steven
    Pectus Carinatum (PC) presents as an overgrowth of costal cartilages resulting in a sternal protrusion. Treatment of PC is performed with a pectus carinatum orthosis (PCO) that compresses the protrusion. Injuries may arise when this PCO is over-tightened. For the first time, a force measurement system (FMS) was constructed that measured PCO forces. The purpose of this study was to determine if participants could accurately attain their clinically prescribed force (CF) over time, and if the protrusion stiffness (PS) influences the participant-applied forces (PF) and correction rate (CR). Results demonstrated that most PFs (75%) exceeded their associated CF (0.46-5.01 lbs). Further investigation is required to determine clinical significance. PS had a positive relationship with PF, but no relationship with CR. Future studies focusing on improved displacement measurements would enhance the ability to quantify PS. Developing a FMS to provide real-time feedback should also be considered to improve PCO efficacy.
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    Centroid of Volume: A Surface Topography Measure used to Detect Changes in Adolescent Idiopathic Scoliosis
    (2016-02-03) Melia, Alexandra; Ronsky, Janet; Joughin, Elaine; Habib, Ayman
    Adolescent Idiopathic Scoliosis (AIS) is a complex three-dimensional (3D) deformity that affects 2-3% of the population. Current methods of diagnosing and monitoring AIS are repeated two-dimensional X-rays every 6-12 months. Repeated radiographs have been shown to increase cancer risk and do not account for 3D changes in the spine. To overcome these drawbacks, the University of Calgary Scoliosis group has developed a non-radiographic imaging technique to analyze 3D deformities using Surface Topography (ST). The overarching objective is to validate a set of ST indices to reliably detect scoliosis. A new ST index, Centroid of Volume (COV), that is a 3D measure of torso balance, is investigated in this thesis. This work found that COV detected differences between healthy and AIS groups and was moderately correlated to the Cobb angle. This index shows promise to detect AIS, which could help advance ST as a clinical tool for monitoring or detecting scoliosis.
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    Characterizing the structure-function relationship of hand osteoarthritis using dynamic and high resolution CT imaging
    (2024-03-27) Kuczynski, Michael Tadeusz; Manske, Sarah; Ronsky, Janet; Edwards, W. Brent; Schneider, Prism
    Osteoarthritis (OA) is the most common form of arthritis and affects the trapeziometacarpal (TMC) joint. While the etiology of OA is still not fully understood, it is a multifactorial disease with biomechanical factors associated in its development. The thumb is estimated to account for over 40% of the hand’s entire function, largely due to the TMC joint. A better understanding of structural and functional changes in TMC OA may improve our understanding of this degenerative joint disease. A recent advancement in computed tomography (CT) now allows for imaging moving joints in vivo. This technique, termed dynamic CT, provides a unique opportunity to quantify joint biomechanics in vivo. In this thesis, novel methodologies are presented that improve processing of dynamic and high-resolution peripheral quantitative CT (HR-pQCT) scans. These methodologies allow for semi-automated quantification of joint space and bone mineral density (BMD) in HR-pQCT scans and biomechanical outcomes from dynamic CT. The methodologies developed in this dissertation drastically reduce processing time for dynamic CT scans compared to previous literature. A cross-sectional study is presented that utilizes HR-pQCT to measure joint space (JS) changes in hand OA, the first of its kind. Maximum JS was significantly greater in OA than controls in the second and third distal interphalangeal (DIP2, DIP3) joints (DIP2: 2.07 mm vs. 1.88 mm; DIP3: 2.01 mm vs. 1.86 mm), and decreased hand function and increased hand disability were associated with increased radiographic TMC OA. A study was conducted to characterize normal TMC joint biomechanics in vivo using the presented methodologies. BMD was computed in anatomical quadrants of the TMC joint, and it was found that the radial-volar quadrant of the first metacarpal (426 mg HA/cm3) and ulnar-volar quadrant of the trapezium (373 mg HA/cm3) were significantly greater than other quadrants. When compared with proximity maps from dynamic CT, areas with high contact corresponded to quadrants with higher BMD. The results from this dissertation provide methodologies to analyze bone and joint changes with HR-pQCT and dynamic CT to better understand hand osteoarthritis.
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    Effect of aging on tibiofemoral cartilage and meniscal stiffness
    (2017) Ritchie, Brodie; Ronsky, Janet; Shrive, Nigel; Edwards, Brent
    Knee osteoarthritis (OA) is a prevalent degenerative cartilage disease characterized by degradation and loss of articular cartilage. Current OA diagnosis methods are ineffective at detecting and monitoring early signs of degeneration in the joint. Changes in mechanical properties of the tissue such as stiffness, or ability to resist compressive load, could present a more sensitive measure for the detection of early OA. This study has developed a novel methodology for the in-vivo measurement of tibiofemoral cartilage and meniscal stiffness using dual fluoroscopy (DF) and magnetic resonance (MR) imaging. This study further aimed to advance understanding of changes in cartilage and meniscal stiffness with normal aging, as age is generally believed to be a leading risk factor for OA. Two groups of five normal males (20-30 and 50-60 years of age) were tested to determine median cartilage and meniscal stiffness over a 5-minute static loading trial. Cartilage and meniscal stiffness was found to significantly increase by 12.51 N/mm (p=0.009) with age. The 20-30 year old group median was 3.39 N/mm (interquartile range (IQR)=2.01-7.29 N/mm) while the 50-60 year old group median was 15.90 N/mm (IQR=11.35-21.17 N/mm). This study contributes toward advancement of early OA clinical diagnostics by demonstrating the presence of significant changes in cartilage and meniscal stiffness with normal aging.
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    Estimation of Ground Reaction Forces in Bucking Rodeo Bulls
    (2006) Savage, Luke; Butterwick, Dale J.; Loitz-Ramage, Barbara; Ronsky, Janet
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    Identifying the Impact of Injury Definition and Training Load on the Study of Jumper’s Knee
    (2016) MacDonald, Kerry; Meeuwisse, Willem; MacKenzie, Don; Emery, Carolyn; Palacios-Derflingher, Luz Maria; Ronsky, Janet
    With a growing body of research into volleyball injuries we are beginning to understand potential risk factors for the most prevalent injuries. Volleyball has been found to have more overuse than acute injuries, yet the majority of research to date has failed to utilize an injury definition sensitive enough to capture the true frequency and burden of overuse problems. Furthermore, the mechanism of overuse injuries is believed to be a chronic overloading of tissue, in combination with an incomplete healing process. With advancements in technology, it is now possible to accurately and efficiently measure these loads which, in turn, could have significant impact on injury prevention. Previously identified risk factors were assessed with the purpose of developing a sport-specific screening program. The impact of injury definition on the data collection for overuse injuries was also examined. This analysis evaluation confirmed the need to use specific overuse injury definitions, with an improved sensitivity for the capture of overuse injury frequency and burden compared to more conventional time-loss definitions. An assessment of known risk factors, including a measure of jumping load, was completed with the more sensitive overuse injury capture. Although no risk factor was found to significantly predict injury outcome, several methodological challenges were identified. This research demonstrates that traditional assessment techniques that have been used for time-loss injuries are not sufficient for overuse injury capture and analyses. The contribution of this dissertation to the literature is the demonstration that the methods presented can more accurately capture the injury burden and record the specific load metrics for that injury. However, further advancements in statistical analysis for prevalence measures of injury are required to assess dynamic risk factors, including measures of load, for overuse injuries.
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    Meniscus Structure and Function
    (2013-01-28) Andrews, Stephen; Ronsky, Janet
    The knee menisci are commonly injured, and do not heal well as a result of their minimal vascularity and severe loading environment. Further, removal of the menisci is detrimental to the long term health of the knee joint. This objective of this body of work was to implement an integrated approach to better understand the function of the menisci as it relates to their fine structure and composition. This approach included mechanical, structural and biochemical analyses, of the menisci using a bovine model. A thorough assessment of the relevant literature led to the conclusion that menisci do not act as a shock absorber in the knee, as was previously believed. To probe the relations between osmolarity and material properties, it was identified experimentally that meniscal samples swell significantly under iso-osmotic conditions. This swelling results in greatly altered mechanical properties in those samples. The osmolarity independent swelling indicates that the menisci are a pre-stressed structure. For the first time, a novel imaging modality, optical projection tomography (OPT) was successfully used to examine connective tissue structure. With OPT, the highly complex, three-dimensional collagen matrix organization within the meniscus was revealed. OPT was also capable of visualizing blood vessel organization in meniscal samples. The localization of the matrix molecules, aggrecan, type II collagen, elastin and proteoglycan 4 were evaluated using various histological and immunofluorescence techniques. The localization was examined as it related to the various architectural subunits of the menisci to further elucidate the composition and organization of those regions. These techniques led to the identification of a new region in the menisci; a proteoglycan-rich, peri-vascular region. It is hypothesized that this region plays a protective role for blood vessels in the menisci. It was further identified that elastin has a region specific distribution which suggests a mechanical role for this protein in the menisci. Collagen II and aggrecan were observed to co-localize in the menisci, indicating similarities with other connective tissues that undergo compressive loading. Finally, these findings were integrated into a novel structural model of meniscal function, which proposes mechanical roles for each of the architectural sub-regions of the menisci.
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    Physical Activity, Adiposity, and Functional Measures in Youth with Juvenile Idiopathic Arthritis Compared to Healthy Controls
    (2018-01-08) Nesbitt, Colleen; Emery, Carolyn; Ronsky, Janet; Kuntze, Gregor; Toomey, Clodagh; Benseler, Susanne
    Objective: To examine habitual physical activity, aerobic capacity, adiposity, and dynamic balance skills in children with JIA, inclusive of knee involvement, compared to age and sex matched healthy controls. Design: Cohort study with a matched-pair design Participants: Twenty-five youth with JIA, ages 10-20, (16 female, 9 male) were matched by age and sex to 25 healthy control participants. Methods: Physical activity data was collected using an ActiGraph accelerometer for 7 days. Aerobic capacity (relative VO2peak) was assessed by a maximal bike test. Adiposity (fat mass index) was evaluated by dual energy X-ray absorptiometry (DXA). Three dynamic balance tests examined balance performance. Results: No significant difference between groups was found in any of the outcomes after adjusting for multiple comparisons. Conclusions: Youth with JIA have similar physical activity, aerobic fitness, adiposity, and functional balance ability as their healthy peers. Differences found in physical activity between male groups could have clinical significance.
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    Qualifying the Variability of Surface Topography Indices for Detection of Clinical Progression of Scoliosis
    (2013-01-09) Dubetz, Tyler Paul Arthur; Ronsky, Janet
    Surface topography (ST) measurements of scoliotic deformities offer the potential to reduce radiation and to provide a more complete description of the deformity when compared to standard X-rays. These ST measurements must be evaluated within a clinical context to determine their feasibility for clinical and research applications. This study quantifies the variability in a set of developed ST indices and estimates a magnitude of clinically important difference based on current clinical standards. The variability is compared to the clinically important difference to determine if the system is adequate for clinical implementation (individual evaluation) or research implementation (group-to-group comparisons). Nine of ten ST indices were found acceptable for typical research implementation. One of ten ST indices (aspect ratio) was found acceptable for typical clinical implementation. Aspect ratio also shows a trend towards differentiating between progressed and non-progressed scoliosis. However, the estimation of what constitutes clinically important difference should be examined further.
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    The Effect of Stochastic Resonance Stimulation on Proprioception and Postural Control in Anterior Cruciate Ligament Reconstructed Patients
    (2017) Zandiyeh, Payam; Ronsky, Janet; Goldsmith, Peter; Von Tscharner, Vinzenz; Nettel-Aguirre, Alberto; Mohtadi, Nicholas; Ferguson-Pell, Martin
    The anterior cruciate ligament (ACL) is one of the most commonly injured ligaments in the knee that frequently results in reconstruction surgery. Some degree of chronic proprioception and postural balance deficiency has been reported following ACL reconstruction (ACLR) surgery, which may be associated with a higher risk of ACL re-injury in these patients. Stochastic resonance (SR) has been shown to improve proprioception in various clinical populations with comparable postural and proprioceptive deficiencies as the ACLR population. In this dissertation, the existence of such deficiencies has been investigated in female ACLR participants and healthy controls. The effect of SR on improving the postural balance and knee proprioception in ACLR and healthy populations has also been studied. The ACLR participants were tested at three months (n = 19) and six months post-surgery (n = 15), while healthy participants were tested once (n = 28). The SR vibration was applied locally to the knee region. Proprioception was evaluated using movement threshold and movement repeatability tests. The effects of the following factors on proprioception were studied: SR (ON vs. OFF), movement direction (flexion vs. extension), and limb condition (ACLR vs. contralateral; ACLR vs. healthy dominant control). Postural balance during single leg standing (duration of 30 sec) was assessed with new measures including entropic half-life (EnHL) and surrogate entropy (ΔE_surr). These measures were developed in conjunction with this dissertation. The effects of the following factors on postural balance were studied: SR (ON vs. OFF), limb side (ACLR vs. contralateral; ACLR vs. healthy dominant control), and vision (eyes open vs. eyes closed). SR vibration successfully improved proprioception in the ACLR and healthy controls. These study results suggest that SR could potentially aid in pre/post-surgery proprioception rehabilitation. This study showed that a postural balance deficiency was present when the ACLR limb was compared to healthy dominant control limbs. When the ACLR limb was compared to the contralateral, the deficiency was only present when the eyes were closed. These findings may suggest that the postural balance deficiency is subtle. Therefore, more stringent or demanding experimental protocols may be necessary to test postural balance in functional groups with deficiencies such as the ACLR group.b