13 results on '"Gislason, M. K."'
Search Results
2. Towards an App to Estimate Patient-Specific Perioperative Femur Fracture Risk
- Author
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Esposito, L., primary, Minutolo, V., additional, Gargiulo, P., additional, Jonsson, H., additional, Gislason, M. K., additional, and Fraldi, M., additional
- Published
- 2020
- Full Text
- View/download PDF
3. Validity and reliability of an iPad with a three-dimensional camera for posture imaging
- Author
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Agustsson, A., Gislason, M. K., Ingvarsson, P., Rodby-Bousquet, Elisabet, Sveinsson, Th, Agustsson, A., Gislason, M. K., Ingvarsson, P., Rodby-Bousquet, Elisabet, and Sveinsson, Th
- Abstract
Background: It is important to quantify a static posture to evaluate the need for and effectiveness of interventions such as physical management, physiotherapy, spinal orthosis or surgical treatment on the alignment of body segments. Motion analysis systems can be used for this purpose, but they are expensive, require a high degree of technical experience and are not easily accessible. A simpler method is needed to quantify static posture. Research objective: Assess validity and inter and intra rater reliability using an iPad with a 3-D camera to evaluate posture and postural deformity. Method: A 3-D model of a lying posture, created using an iPad with a 3-D camera, was compared to a Qualisys motion analysis system of the same lying posture, the latter used as the gold standard. Markers on the trunk and the leg were captured by both systems, and results from distance and angle measurements were compared. Results: All intra-class correlation coefficient values were above 0.98, the highest systematic error was 4.3 mm for length measurements and 0.2 degrees for angle measurements. Significance: A 3-D model of a person, with markers on anatomical landmarks, created with an iPad with a 3-D camera, is a valid and reliable method of quantifying static posture. Conclusion: An iPad with a 3-D camera is a relatively inexpensive, valid and reliable method to quantify static posture in a clinical environment.
- Published
- 2019
- Full Text
- View/download PDF
4. Biomechanical analysis of the Universal 2 implant in total wrist arthroplasty: a finite element study
- Author
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Gislason, M. K., primary, Foster, E., additional, Bransby-Zachary, M., additional, and Nash, D. H., additional
- Published
- 2017
- Full Text
- View/download PDF
5. A three-dimensional finite element model of maximal grip loading in the human wrist
- Author
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Gislason, M K, primary, Nash, D H, additional, Nicol, A, additional, Kanellopoulos, A, additional, Bransby-Zachary, M, additional, Hems, T, additional, Condon, B, additional, and Stansfield, B, additional
- Published
- 2009
- Full Text
- View/download PDF
6. A CT-based method to compute femur remodelling after total hip arthroplasty
- Author
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Halldór Jónsson, Paolo Gargiulo, Luca Cristofolini, Luigi Iuppariello, Luca Esposito, Paolo Bifulco, Antonio Sarno, Magnus K. Gislason, Iuppariello L., Esposito L., Gargiulo P., Gislason M.K., Jonsson H., Sarno A., Cristofolini L., Bifulco P., Iuppariello, L., Esposito, L., Gargiulo, P., Gislason, M. K., Jonsson, H., Sarno, A., Cristofolini, L., and Bifulco, P.
- Subjects
Orthodontics ,business.industry ,prosthesis rigid realignment ,Biomedical Engineering ,Computational Mechanics ,02 engineering and technology ,030218 nuclear medicine & medical imaging ,Computer Science Applications ,Bone remodeling ,femur bone remodelling ,03 medical and health sciences ,0302 clinical medicine ,0202 electrical engineering, electronic engineering, information engineering ,CT image processing ,Medicine ,020201 artificial intelligence & image processing ,Radiology, Nuclear Medicine and imaging ,Femur ,Total hip arthroplasty ,business - Abstract
Bone remodelling after total hip arthroplasty has been largely observed and investigated. Most studies rely on projective images and only few obtain 3D information with limited spatial resolution. This study proposes a method to provide quantitative, 3D high-resolution data about femur bone density variations, by means of CT volume processing. This would offer a tool for further research and clinical studies. Five patients subjected to primary, cementless total hip arthroplasty were considered. Calibrated CT volumes were acquired before, just after surgery and 1 yr later. Bone remodelling hinders accurate alignment of femur volumes acquired after a year; instead, prosthesis stem remains unchanged. Thus, after metal artefact reduction, prosthesis was segmented, and stem-based accurate alignment was obtained. A test to exclude prosthesis migration was performed by considering specific femur anatomical landmarks. Bone density error due to artefact reduction and realignment was estimated. Quantitative differences in bone mineral density were computed for each voxel, providing a resolution of about 1 mm. Preliminary results showed that the femur underwent consistent remodelling after a year. Widespread bone density losses appeared in those areas where strain-adaptive remodelling is normally expected, particularly about the calcar. Conversely, distal areas with clear stem-bone contact showed considerable density gains.
- Published
- 2021
7. Towards an App to Estimate Patient-Specific Perioperative Femur Fracture Risk
- Author
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Luca Esposito, Vincenzo Minutolo, Paolo Gargiulo, Halldór Jónsson, Massimiliano Fraldi, Magnus K. Gislason, Esposito, L., Minutolo, V., Gargiulo, P., Jonsson, H., Gislason, M. K., and Fraldi, M.
- Subjects
medicine.medical_specialty ,total hip arthroplasty ,bone elastic-plastic behavior ,media_common.quotation_subject ,0206 medical engineering ,02 engineering and technology ,lcsh:Technology ,lcsh:Chemistry ,03 medical and health sciences ,0302 clinical medicine ,medicine ,General Materials Science ,Quality (business) ,Instrumentation ,lcsh:QH301-705.5 ,media_common ,Fluid Flow and Transfer Processes ,High rate ,030222 orthopedics ,Femur fracture ,business.industry ,lcsh:T ,Process Chemistry and Technology ,General Engineering ,Perioperative ,Patient specific ,intra-operative femur fracture risk ,020601 biomedical engineering ,lcsh:QC1-999 ,Computer Science Applications ,lcsh:Biology (General) ,lcsh:QD1-999 ,lcsh:TA1-2040 ,Life expectancy ,Physical therapy ,Implant ,business ,lcsh:Engineering (General). Civil engineering (General) ,lcsh:Physics ,Total hip arthroplasty - Abstract
Total Hip Arthroplasty has been one of the most successful surgical procedure in terms of patient outcomes and satisfaction. However, due to increase in life expectancy and the related incidence of age-dependent bone diseases, a growing number of cases of intra-operative fractures lead to revision surgery with high rates of morbidity and mortality. Surgeons choose the type of the implant, either cemented or cementless prosthesis, on the basis of the age, the quality of the bone and the general medical conditions of the patients. Generally, no quantitative measures are available to assess the intra-operative fracture risk. Consequently, the decision-making process is mainly based on surgical operators&rsquo, expertise and qualitative information obtained from imaging. Motivated by this scenario, we here propose a mechanical-supported strategy to assist surgeons in their decisions, by giving intelligible maps of the risk fracture which take into account the interplay between the actual mechanical strength distribution inside the bone tissue and its response to the forces exerted by the implant. In the presented study, we produce charts and patient-specific synthetic &ldquo, traffic-light&rdquo, indicators of fracture risk, by making use of ad hoc analytical solutions to predict the stress levels in the bone by means of Computed Tomography-based mechanical and geometrical parameters of the patient. We felt that if implemented in a friendly software or proposed as an app, the strategy could constitute a practical tool to help the medical decision-making process, in particular with respect to the choice of adopting cemented or cementless implant.
- Published
- 2020
8. Three dimensional bone mineral density changes in the femur over 1 year in primary total hip arthroplasty patients
- Author
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Halldór Jónsson, Luca Esposito, Paolo Bifulco, Paolo Gargiulo, Massimiliano Fraldi, Magnus K. Gislason, Francesca Lupidio, Luca Cristofolini, Gislason, M. K., Lupidio, F., Jonsson, H., Cristofolini, L., Esposito, L., Bifulco, P., Fraldi, M., Gargiulo, P., Gislason M.K., Lupidio F., Jonsson H., Cristofolini L., Esposito L., Bifulco P., Fraldi M., and Gargiulo P.
- Subjects
Male ,Bone density ,Arthroplasty, Replacement, Hip ,Biophysics ,Post-operative assessment ,03 medical and health sciences ,0302 clinical medicine ,Bone Density ,Hounsfield scale ,Bone mineral density ,Medicine ,Humans ,Orthopedics and Sports Medicine ,Femur ,Total joint replacement ,Aged ,Bone mineral ,business.industry ,030229 sport sciences ,Middle Aged ,Lesser Trochanter ,Total hip arthroplasty ,Female ,Implant ,Hip Prosthesis ,business ,Nuclear medicine ,Tomography, X-Ray Computed ,030217 neurology & neurosurgery - Abstract
Background The aim of the study was to compare the bone mineral density changes between unmatched patients undergoing total hip arthroplasty receiving uncemented and cemented type of implants. Previous studies have used DEXA or a two dimensional analysis to estimate the bone quality following total joint replacement, whereas this study presents the changes in three dimensions. Methods Fifty subjects both male and females receiving both cemented and uncemented type of implant were recruited. Two CT scans were taken of each subject, the first at 24 h post surgery and the second one 1 year after surgery. The scans were calibrated using a phantom converting the Hounsfield units to bone mineral density values in g/cm3. The two scans were registered together using anatomical landmarks and resliced to compare the two femurs in the identical frame of reference. The bone density gain and loss was calculated by comparing density values between the two sets of scans. Findings The results showed that most of the bone loss was located around the Lesser Trochanter and some bone density gain at the distal tip of the implant. The three dimensional density changes occur differently between individuals and the study showed no correlation of bone loss with age. Interpretation The bone loss occurred mostly at the proximal femur, which is in agreement with previously presented studies. By carrying out three dimensional analysis on the bone gain and loss on the femur, it is possible to identify the patients that are showing high degree of bone loss.
- Published
- 2020
9. Improving prosthetic selection and predicting BMD from biometric measurements in patients receiving total hip arthroplasty
- Author
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Paolo Gargiulo, Carlo Ricciardi, Marco Recenti, Halldór Jónsson, Magnus K. Gislason, Luca Esposito, Vincenzo Minutolo, Giuseppe Cesarelli, Paolo Bifulco, Giovanni Improta, Deborah Jacob, Ricciardi, C., Halldór, J., J, R., Jacob, D., Improta, G., Recenti, M., Gíslason, M. K., Cesarelli, G., Esposito, L., Minutolo, V., Bifulco, P., Gargiulo, P., Halldor, J., and Gislason, M. K.
- Subjects
medicine.medical_specialty ,electromyography ,total hip arthroplasty ,Biometrics ,medicine.medical_treatment ,0206 medical engineering ,Clinical Biochemistry ,Dentistry ,02 engineering and technology ,Electromyography ,database analyses ,clinical decision making ,Prosthesis ,Article ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Femur ,Bone mineral ,lcsh:R5-920 ,medicine.diagnostic_test ,business.industry ,030229 sport sciences ,020601 biomedical engineering ,machine learning ,Gait analysis ,Orthopedic surgery ,database analyse ,business ,lcsh:Medicine (General) ,Total hip arthroplasty - Abstract
There are two surgical approaches to performing total hip arthroplasty (THA): a cemented or uncemented type of prosthesis. The choice is usually based on the experience of the orthopaedic surgeon and on parameters such as the age and gender of the patient. Using machine learning (ML) techniques on quantitative biomechanical and bone quality data extracted from computed tomography, electromyography and gait analysis, the aim of this paper was, firstly, to help clinicians use patient-specific biomarkers from diagnostic exams in the prosthetic decision-making process. The second aim was to evaluate patient long-term outcomes by predicting the bone mineral density (BMD) of the proximal and distal parts of the femur using advanced image processing analysis techniques and ML. The ML analyses were performed on diagnostic patient data extracted from a national database of 51 THA patients using the Knime analytics platform. The classification analysis achieved 93% accuracy in choosing the type of prosthesis, the regression analysis on the BMD data showed a coefficient of determination of about 0.6. The start and stop of the electromyographic signals were identified as the best predictors. This study shows a patient-specific approach could be helpful in the decision-making process and provide clinicians with information regarding the follow up of patients.
- Published
- 2020
10. CT-Based Bone and Muscle Assessment in Normal and Pathological Conditions
- Author
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Halldór Jónsson, Massimiliano Fraldi, Jonathan Pitocchi, Magnus K. Gislason, Mario Cesarelli, Paolo Gargiulo, Ugo Carraro, Paolo Bifulco, Kyle J. Edmunds, Luca Esposito, P Gargiulo, MK Gislason, KJ Edmunds, J Pitocchi, U Carraro, L Esposito, M Fraldi, P Bifulco, M Cesarelli, H Jónsson, Gargiulo, P., Gislason, M. K., Edmunds, K. J., Pitocchi, J., Carraro, U., Esposito, L., Fraldi, M., Bifulco, P., Cesarelli, M., Jónsson, H., Gargiulo, Paolo, Gislason, Magnus K., Edmunds, Kyle J., Pitocchi, Jonathan, Carraro, Ugo, Esposito, Luca, Fraldi, Massimiliano, Bifulco, Paolo, Cesarelli, Mario, and Jónsson, Halldór
- Subjects
Muscle morphology ,medicine.anatomical_structure ,medicine.diagnostic_test ,In vivo ,business.industry ,Medical imaging ,medicine ,Distribution (pharmacology) ,Computed tomography ,business ,Bone tissue ,Pathological ,Biomedical engineering - Abstract
This article outlines the methods and applications of threshold-based techniques to assess in vivo muscle and bone tissue distribution in normal and pathological conditions using computed tomography imaging. The approaches described here use medical imaging processing techniques and computational methods to study bone mechanical proprieties, analyze and quantify muscle morphology, visualize changes with 3-D models, develop subject-specific numerical profiles, and assess muscle and bone changes during clinical treatments.
- Published
- 2019
11. Patient-specific mobility assessment to monitor recovery after total hip arthroplasty
- Author
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Paolo Gargiulo, Þrostur Hermannsson, Magnus K. Gislason, Mario Cesarelli, Massimiliano Fraldi, Paolo Bifulco, Luca Esposito, Chase D. Latour, Kyle J. Edmunds, Luca Cristofolini, Halldór Jónsson, Gargiulo, P., Edmunds, K. J., Gislason, M. K., Latour, C., Hermannsson, Th., Esposito, L., Bifulco, P., Cesarelli, M., Fraldi, M., Cristofolini, L., Jonsson, H., Gíslason, M. K., Hermannsson, Þ., Jónsson, H., Gargiulo P., Edmunds K.J., Gislason M.K., Latour C., Hermannsson Th., Esposito L., Bifulco P., Cesarelli M., Fraldi M., Cristofolini L., and Jonsson H.
- Subjects
medicine.medical_specialty ,Arthroplasty, Replacement, Hip ,Movement ,Periprosthetic ,clinical outcome prediction ,hip prosthese ,03 medical and health sciences ,0302 clinical medicine ,Bone Density ,Bone biomechanics ,Humans ,Medicine ,Postoperative Period ,Gait ,business.industry ,Muscles ,Mechanical Engineering ,mathematical modeling ,Orthopedic Surgical Procedure ,030229 sport sciences ,General Medicine ,Recovery of Function ,Patient specific ,finite element analysi ,Surgery ,Biomechanical Phenomena ,Bone biomechanic ,Muscle ,business ,Tomography, X-Ray Computed ,030217 neurology & neurosurgery ,Total hip arthroplasty ,Human - Abstract
Total hip arthroplasty is a ubiquitously successful orthopedic surgical procedure, whose prevalence is rising worldwide. While many investigations focus on characterizing periprosthetic pathophysiology, the objective of our research is to develop and describe multi-metric assemblies as a first step toward creating a patient-specific mobility index that rehabilitators and orthopedic surgeons can utilize for prescribing their respective procedures. In total, 48 total hip arthroplasty patients (both cemented and uncemented) undergoing unilateral, primary surgery went through computed tomographic scans and gait analysis measurements both before and 1 year following their surgery. Altogether, the reported quantitative metrics include 11 spatial and temporal gait parameters, muscle density, and electromyography signals from the rectus femoris, vastus lateralis, and vastus medialis, and bone mineral density values from bioimage analysis around the implant stem. We found that measured parameters from a subgroup were sensitive to changes observed during patient recovery, implicating the predictive sensitivity of these patient conditions. Most post-operative gait parameters changed significantly, while electromyography data indicated few significant differences. Moreover, results from bioimage analyses indicate a general reduction of periprosthetic bone mineral density after 1 year, in association with increasing density of the quadriceps muscles. Furthermore, this work identifies which quantitative metrics undergo the greatest variation after total hip arthroplasty and demonstrates the clinical feasibility of a multimodal approach to mobility assessment that may ultimately support decision-making for post-surgical rehabilitation protocols.
- Published
- 2018
12. Validity and reliability of an iPad with a three-dimensional camera for posture imaging.
- Author
-
Agustsson A, Gislason MK, Ingvarsson P, Rodby-Bousquet E, and Sveinsson T
- Subjects
- Adult, Back physiology, Computers, Handheld, Female, Humans, Imaging, Three-Dimensional instrumentation, Male, Middle Aged, Reproducibility of Results, Torso physiology, Imaging, Three-Dimensional methods, Posture physiology
- Abstract
Background: It is important to quantify a static posture to evaluate the need for and effectiveness of interventions such as physical management, physiotherapy, spinal orthosis or surgical treatment on the alignment of body segments. Motion analysis systems can be used for this purpose, but they are expensive, require a high degree of technical experience and are not easily accessible. A simpler method is needed to quantify static posture., Research Objective: Assess validity and inter and intra rater reliability using an iPad with a 3-D camera to evaluate posture and postural deformity., Method: A 3-D model of a lying posture, created using an iPad with a 3-D camera, was compared to a Qualisys motion analysis system of the same lying posture, the latter used as the gold standard. Markers on the trunk and the leg were captured by both systems, and results from distance and angle measurements were compared., Results: All intra-class correlation coefficient values were above 0.98, the highest systematic error was 4.3 mm for length measurements and 0.2° for angle measurements., Significance: A 3-D model of a person, with markers on anatomical landmarks, created with an iPad with a 3-D camera, is a valid and reliable method of quantifying static posture., Conclusion: An iPad with a 3-D camera is a relatively inexpensive, valid and reliable method to quantify static posture in a clinical environment., (Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
13. Mechanical testing and modelling of the Universal 2 implant.
- Author
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Gislason MK, Foster E, Main D, Fusiek G, Niewczas P, Bransby-Zachary M, and Nash DH
- Subjects
- Materials Testing instrumentation, Stress, Mechanical, Finite Element Analysis, Materials Testing methods, Mechanical Phenomena, Prostheses and Implants
- Abstract
Understanding the load mechanics of orthopaedic implants is important to be able to predict their behaviour in-vivo. Much research, both mechanical and clinical, has been carried out on hip and knee implants, but less has been written about the mechanics of wrist implants. In this paper, the load mechanics of the Universal 2 wrist implant have been measured using two types of measuring techniques, strain gauges and Fibre Bragg Grating measurements to measure strains. The results were compared to a finite element model of the implant. The results showed that the computational results were in good agreement with the experimental results. Better understanding of the load mechanics of wrist implants, using models and experimental results can catalyse the development of future generation implants., (Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
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