Engineering Commons^™

Kinematic Analysis Of Gait And Deep Knee Flexion For Pre- And Post-Operative Total Knee Arthroplasty, Samantha Collins

Electronic Theses and Dissertations

Osteoarthritis (OA) is a form of arthritis that develops in the joint due to overuse and aging causing pain, discomfort, and disability. Total Knee Arthroplasty (TKA) is a surgical procedure performed when OA symptoms are severe with an estimated 600,000 patients in the United States currently receiving TKA. Studies have reported dissatisfaction of the knee for 14-39% of patients. This study collected knee kinematics before and after surgery using stereo radiography for precise measurement of gait and deep knee flexion activities. Results showed healthy knee kinematics were not restored and no significant changes could be seen from OA kinematics in …

Digital Twins Of The Living Knee: From Measurements To Model, Thor Erik Andreassen

Electronic Theses and Dissertations

Modern medicine has dramatically improved the lives of many. In orthopaedics, robotic surgery has given clinicians superior accuracy when performing interventions over conventional methods. Nevertheless, while these and many other methods are available to ensure treatments are performed successfully, far fewer methods exist to predict the proper treatment option for a given person. Clinicians are forced to categorize individuals, choosing the best treatment on “average.” However, many individuals differ significantly from the “average” person, for which many of these treatments are designed. Going forward, a method of testing, evaluating, and predicting different treatment options' short- and long-term effects on an …

Computational Methodology For Generating Patient-Specific Soft Tissue Representations, Ahilan Anantha Krishnan

Electronic Theses and Dissertations

This dissertation focused on modeling specimen-specific soft tissue structures in the context of joint replacement surgery. The research addressed four key aspects. The first study involved developing a workflow for creating finite element models of the hip capsule to replicate its torque-rotational response. Experimental data from ten cadaveric hips were used to calibrate the models, resulting in improved accuracy and relevance for surgical planning and implant design. The second study tackled the challenge of expediting the calibration of mechanical properties of the hip capsule to match patient-specific laxities. A statistical shape function model was proposed to generate patient-specific finite element …

Finite Element Modeling Of Patient-Specific Total Shoulder Arthroplasty, Ignacio Rivero Crespo

Electronic Theses and Dissertations

Total Shoulder Arthroplasty (TSA) is a surgical procedure designed to improve joint functionality by replacing the articulation between the humeral head and the glenoid fossa. Anatomic Total Shoulder Arthroplasty (aTSA) and Reverse Total Shoulder Arthroplasty (rTSA) are two types of replacement surgery to relieve pain and restore function of the shoulder. The overall goal of this study was to evaluate the effects of variation of certain patient and implant alignment parameters that may influence long-term outcomes of these surgical procedures, including kinematics, joint loads and contact mechanics. Computational models of six TSA subjects, three aTSA and three rTSA, were created …

Patient Movement Monitoring Based On Imu And Deep Learning, Mohsen Sharifi Renani

Electronic Theses and Dissertations

Osteoarthritis (OA) is the leading cause of disability among the aging population in the United States and is frequently treated by replacing deteriorated joints with metal and plastic components. Developing better quantitative measures of movement quality to track patients longitudinally in their own homes would enable personalized treatment plans and hasten the advancement of promising new interventions. Wearable sensors and machine learning used to quantify patient movement could revolutionize the diagnosis and treatment of movement disorders. The purpose of this dissertation was to overcome technical challenges associated with the use of wearable sensors, specifically Inertial Measurement Units (IMUs), as a …

Improving Quantification Of Mitral Regurgitation Through Computational Fluid Dynamics And Ex Vivo Testing, Alexandra Flowers

Electronic Theses and Dissertations

Mitral regurgitation (MR) is a prominent cardiac disease affecting more than two million people in the United States alone. In order for patients to receive proper therapy, regurgitant volume must first be quantified. As there are an array of methods to do so, the proximal isovelocity surface area (PISA) method continues to be the most accurate and clinically used method. However, there are some difficulties obtaining the necessary measurements need for this when performing transthoracic echocardiography. This study aims to evaluate and present techniques that may be used to more accurately quantify regurgitation through ex vivo testing and computational fluid …

Pulmonary Valve Replacement, Mina Shafiei

Electronic Theses and Dissertations

Currently, transcatheter pulmonary valve replacement (TPVR) is a well-established alternative for surgical pulmonary valve replacement (SPVR) to treat pulmonary valve disorders in patients with prior congenital heart surgery. Edwards Sapien 3 valve is a bioprosthesis originally designed for the aortic position but has been used off-label in native right ventricular outflow tract (RVOT). It is currently under clinical trial to get food and drug administration (FDA) approval.

This study is a comparison of the performance of Sapien 3 with surgical bioprosthetics. The in vitro tests result showed Sapien 3 experiences less degree of opening and effective orifice area in pulmonic …

Structural And Hemodynamic Analysis Of Transcatheter Aortic Valves, Dong Qiu

Electronic Theses and Dissertations

The transcatheter aortic valve replacement (TAVR) procedure has become a well-established procedure for high, intermediate-risk, and low-risk patients. However, there is limited clinical data on the TAV's long-term durability, unlike SAV devices. Computational simulations can be an alternative way to evaluate the TAV devices. This dissertation aims to conduct structural and hemodynamic analyses on the TAV devices under different conditions using computational simulation approaches.

Initially, the impact of the bicuspid aortic valve on the TAV devices was evaluated. The result indicated that the CoreValve-like supra-annular self-expandable device was likely to have increased stress and strain on the leaflet when it …

An Investigation Into The Plate Fixation For Periprosthetic Femoral Fractures, Xiang Chen

Electronic Theses and Dissertations

Periprosthetic femoral fractures are the third most reason for reoperation after the total hip arthroplasty with an incident rate of approximately 6%. The Vancouver type B periprosthetic femoral fractures account for over 70% of all cases, while the sub-type B1 fracture (when the total hip stem is stable) has remained a clinical challenge due to incidences of severe complications after the standard plate-screw fixation. To seek biomechanically sound fixations for the Vancouver type B1 fracture, this dissertation developed a combined modeling and testing framework to investigate the efficacy of fixation for a Vancouver type B1 fracture using different construct lengths …

Revision Total Hip Femoral Stem Micromotion And Statistical Shape Modeling Of The Knee, William Fugit

Electronic Theses and Dissertations

The first purpose of this thesis was to compare the amount of micromotion seen in the femoral stem in a revision total hip arthroplasty between simple loading conditions and loading conditions derived from activities of daily living, through the use of experimental and computational methods. The amount of micromotion at the bone-implant interface was larger for activities of daily living, with ranges of 200μm more than the largest simple loading conditions. The second purpose of this thesis was to compare measurements of accuracy in a statistical shape model between individual bone and joint-level models, specifically for the knee. Using computational …

An Accuracy And Precision Analysis Of The Velys™ Robotic Assisted Solution For Total Knee Arthroplasty, Gary Doan

Electronic Theses and Dissertations

Total knee arthroplasty (TKA) is a procedure where the arthritic surfaces of the knee is removed and replaced with a combination of metal and polymer implants that recreates the joint line to restore function and quality of life. Implant alignment is important in the success of a TKA. Modern day conventional instrumentation can be cumbersome in the operating room and can be inaccurate when resecting bone and aligning implants. Patients with large errors in resections and implant orientation are more prone to experience mechanical failures with their TKA. Mechanical failures in primary TKA require revision surgeries which can lead to …

Accurate Measurement Of Healthy Joint Kinematics To Inform Diagnosis And Treatment, Vasiliki Kefala

Electronic Theses and Dissertations

The description of human motion has a primary importance in different scientific areas such as medicine, sports, physical therapy. Kinematics specifically studies pure motion without reference to the causes of motion such as forces. Understanding the kinematics of human movement is of critical importance in medicine and biology. Motion measure­ment can be used in order to to evaluate functional performance of limbs under normal and abnormal conditions. Kinematic knowledge is also important for diagnosis and surgi­cal treatment of joint disease and the design of implants to rehabilitate function. Accurate joint kinematics is essential to protect articular functionality. An alteration may …

Dislocation Mechanics Of Total Hip Arthroplasty: A Combined Experimental And Computational Analysis, Michael Scinto

Electronic Theses and Dissertations

While total hip arthroplasty is considered a successful procedure, dislocation remains a serious complication as recurrent dislocations may require additional surgeries. Knowledge on dislocation events as they occur in vivo are limited, therefore researchers rely on experimental and computational methods. A custom MATLAB script and an experimental procedure utilizing a six-degree of freedom actuator were developed to further understand how various surgical considerations affect dislocation mechanics in total hip arthroplasty. Computationally, it was determined that impingement free range of motion is limited during internal rotation in flexion and during external rotation in extension. Experimentally, our results suggest that the posterior …

Transcatheter Mitral Valve Replacement: Structural And Hemodynamic Analysis, Saba Ravaghi

Electronic Theses and Dissertations

Transcatheter mitral valve replacement (TMVR) is being developed to become a substitute therapy for surgery in prohibitive or high surgical risk patients to treat severe mitral regurgitation. A limited number of TMVR systems are under clinical evaluation. However, transcatheter mitral valve (TMV) long-term durability and hemodynamic performance is not known. TMV durability and hemodynamics must match with that of surgical bioprostheses for potential commercialization of TMVR. Experimental and computational approaches were used to find the leaflets’ three-dimensional anisotropic mechanical properties in a transcatheter Edwards SAPIEN 3 valve and a surgical Carpentier-Edwards PERIMOUNT Magna mitral valve and finite element (FE) simulations …

In Vivo Data Capture Using Hssr For Calibration Of Computational Models, Thor Erik Andreassen

Electronic Theses and Dissertations

Computational modeling is a vital tool for understanding and evaluating healthy and unhealthy function of the musculoskeletal aspects of the human body. However, the accuracy of the musculoskeletal models depends significantly on the accuracy of the input data used to calibrate various behavioral parameters of the model. To date, most computational models have been built using generic in vitro data, mostly because of a lack of accurate and meaningful datasets from in vivo testing. The next major step in computational modeling is to create subject-specific computational models using calibration data taken from in vivo testing. The overall goal was to …

The Effects And Analysis Of Implant Type And Surgical Approach In Total Hip Arthroplasty Dislocation Resistance, Brittany Marshall

Electronic Theses and Dissertations

Total hip arthroplasty (THA) is one of the most successful orthopaedic surgeries performed, in which the hip joint is reconstructed to decrease pain and to improve the functionality to the joint. Although these surgeries are very successful, there still remain areas for improvement, such as failures due to instability and dislocation of the implanted joint. The purpose of this thesis is to investigate the effect of surgical entrance approach on dislocation, the effect of implant type, and the effect of capsule repair and closure. The need to quantify the resistance to dislocation is important in understanding the effect that each …

A Longitudinal Examination Of Biomechanical Balance And Quantitative Multidomain Assessments During Recovery Following Sport-Related Concussion, Moira Kate Pyrhoda

Electronic Theses and Dissertations

Sport-related concussion is an inherent risk to athlete health in contact and collision sports. Both short- and long-term risks are associated with the injury. Short-term, athletes may develop post-concussion syndrome (PCS), the persistence of cognitive, physical, and emotional symptoms for weeks or months after injury. Athletes who return to play (RTP) prematurely are at increased risk for lower extremity injury and repeated concussion injuries. Long-term, history of multiple concussions have been linked to neurodegenerative diseases. Due to these risks, concussion assessments must be sensitive to the injury and useful in the diagnosis, recovery, and RTP phases of the injury.

Sideline …

Development Of A Clinical Marker-Less Motion Capture System For Patient Monitoring, Abigail Eustace

Electronic Theses and Dissertations

The ability to understand human movement is beneficial for deciding surgical procedures, tracking disease progression over time and helping with patient rehabilitation. The current gold-standard for collecting human movement is the use of 3-dimensional marker-based systems. Several studies have presented the many limitations to the current gold-standard that reduces the number of people who are able to benefit from a gait analysis. Those limitations in the current gold-standard include the requirements of large laboratory space, costly equipment, long instrumentation and collection time, and the potential for motion artifact from markers being placed on the skin. The purpose of this study …

The Relative Contribution Of Fixation Features, Activity, And Tibiofemoral Conformity On Initial Stability Of Cementless Tibial Trays, James Sullivan Deacy

Electronic Theses and Dissertations

Initial stability of cementless total knee replacements (TKR) is critical to implant success as excessive motion between the bone and implant prevents bony ingrowth that is critical to the long-term survivability of cementless implants. Prior studies have shown that excessive micromotion causes fibrous tissue growth instead of beneficial bony growth. There are many factors that influence initial stability including the design of the tibial tray and the tibiofemoral articulations. Understanding the impacts of these design features on micromotion between the bone and implants is crucial to improving the performance of cementless TKR. Prior studies only tested for the effect of …

Computational Modeling Of Transcatheter Aortic Valves, Mostafa Abbasi

Electronic Theses and Dissertations

Transcatheter aortic valve replacement (TAVR) is an established therapy alternative to surgical valve replacement in high-risk and intermediate-risk patients with severe aortic stenosis. Currently, although TAVR is an alternative and less-invasive treatment for high-risk and intermediate-risk patients, surgical aortic valves replacement (SAVR) was still considered as the gold standard for low-risk patients. TAVR could potentially be applied to lower-risk younger patients if the indications can be safely expanded to the patients and transcatheter aortic valve (TAV) long-term durability can match with that of surgical bioprostheses. In contrast to surgical aortic valves (SAVs), there have been limited clinical data on the …

Predictive Modeling Of Hip Dislocation: Assessment Of Surgical And Patient Factors To Reduce The Occurrence Of Hip Instability And Adverse Clinical Outcomes, Daniel N. Huff

Electronic Theses and Dissertations

Instability and dislocation remain leading indications for revision of primary Total Hip Arthroplasty (THA). Many studies have addressed the links between implant design and propensity for dislocation, however a comprehensive review of the ability of modern THA constructs to protect against joint instability is needed.

Accordingly, the objective of this study is to provide objective data about THA risks to be considered in the treatment algorithm to protect against adverse joint loading conditions and joint instability. Adverse loading conditions were assessed in a population of activities of daily living using data from telemetric hip implant representation in an FE simulation …

Cementless Tibial Base Micromotion During Activities Of Daily Living, Hayden Wilson

Electronic Theses and Dissertations

Initial stability of cementless total knee replacement (TKR) components is directly related to long-term fixation and success, as excess motion hinders bony ingrowth. To assess implant stability, there is a need for more physiologically accurate loading conditions, incorporating forces and displacements in all 6 degrees-of-freedom found in the knee joint, as well as understanding the impact of femoral flexion on conformity of tibiofemoral articulation. Understanding how different activities of daily living generate tibial micromotion yields insight into surgical technique considerations, and rehabilitation strategies post-operatively. ASTM F3141-15, which specifies knee flexion, Internal-External moment, Medial-Lateral, Anterior-Posterior and Superior-Inferior forces during gait and …

Mechanical Effects Of Surgical Adhesives On Ascending Thoracic Aortic Aneurysm Replacement, Dong Qiu

Electronic Theses and Dissertations

Ascending thoracic aortic aneurysm (aTAA) is a potentially lethal disease which grows gradually over time and may lead to aortic dissection and rupture. Currently, aTAA surgical repair using Dacron graft is a well-established treatment. In addition, surgical adhesives are frequently used in the surgeries to seal the anastomotic site. This study aims to investigate mechanical effects of four commonly used surgical adhesives, namely BioGlue, CoSeal, Crosseal, and Tisseel, on the suture site using in-vitro digital image correlation (DIC) method and finite element (FE) simulations in an ovine model. In this study, first, mechanical properties of ovine ascending aorta were obtained …

Statistical Shape And Intensity Modeling Of The Shoulder, Irene Sintini

Electronic Theses and Dissertations

Anatomical variability in the shoulder is inherently present and can influence healthy and pathologic biomechanics and ultimately clinical decision-making. Characterizing variation in bony morphology and material properties in the population can support treatment and specifically the design, via shape and sizing, of shoulder implants. Total Shoulder Arthroplasty (TSA) is the treatment of choice for glenohumeral osteoarthritis as well as bone fracture. Complications and poor outcomes in TSA are generally influenced by the inability of the implant to replicate the natural joint biomechanics and by the bone quality around the fixation features. For this reason, knowledge of bony morphology and mechanical …

Specimen-Specific Natural, Pathological, And Implanted Knee Mechanics Using Finite Element Modeling, Azhar Akber Ali

Electronic Theses and Dissertations

There is an increasing incidence of knee pain and injury among the population, and increasing demand for higher knee function in total knee replacement designs. As a result, clinicians and implant manufacturers are interested in improving patient outcomes, and evaluation of knee mechanics is essential for better diagnosis and repair of knee pathologies. Common knee pathologies include osteoarthritis (degradation of the articulating surfaces), patellofemoral pain, and cruciate ligament injury and/or rupture. The complex behavior of knee motion presents unique challenges in the diagnosis of knee pathology and restoration of healthy knee function. Quantifying knee mechanics is essential for developing successful …

Anatomy, Implant Selection And Placement Influence Spine Mechanics Associated With Total Disc Replacement, Justin F.M. Hollenbeck

Electronic Theses and Dissertations

Through aging and injury, the intervertebral disc of the lumbar spine can undergo degeneration, leading to collapse of the vertebrae and low back pain, a symptom that affects half the adult population in any given year. In an effort to reduce low back pain, total disc replacement treatment removes the degenerated disc, restores natural height and lordosis of the segment, and preserves motion at the joint. Patient anatomy, implant selection, and implant placement play significant roles in a patient's outcomes after total disc replacement surgery. Thus, the objective of the work presented in this thesis was to develop a suite …

Computational Biomechanical Modeling Of The Human Knee During Kneeling, Tariq R. Abo-Alhol

Electronic Theses and Dissertations

Total knee replacement benefits patients who suffer from severe knee pain or joint stiffness and other joint related illnesses that limit everyday activities. There has been an increase in the number of procedures performed each year and a need to evaluate the performance of these implants during specialized activities such as kneeling. Most computational studies lack insight into inter-patient variability and the results do not apply to large population. This study developed: (1) three-dimensional explicit finite element (FE) models to investigate natural and implanted knee joint kinematics and bone strain and (2) a platform to enable population-based evaluation by combining …