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Sim S.,Biomomentum Inc. | Garon M.,Biomomentum Inc. | Quenneville E.,Biomomentum Inc. | Yaroshinsky A.,Vital Systems | And 2 more authors.
Journal of Orthopaedic Research | Year: 2016

Recent advances in the development of new drugs to halt or even reverse the progression of Osteoarthritis at an early-stage requires new tools to detect early degeneration of articular cartilage. We investigated the ability of an electromechanical probe and an automated indentation technique to characterize entire human articular surfaces for rapid non-destructive discrimination between early degenerated and healthy articular cartilage. Human cadaveric asymptomatic articular surfaces (four pairs of distal femurs and four pairs of tibial plateaus) were used. They were assessed ex vivo: macroscopically, electromechanically, (maps of the electromechanical quantitative parameter, QP, reflecting streaming potentials), mechanically (maps of the instantaneous modulus, IM), and through cartilage thickness. Osteochondral cores were also harvested from healthy and degenerated regions for histological assessment, biochemical analyses, and unconfined compression tests. The macroscopic visual assessment delimited three distinct regions on each articular surface: Region I was macroscopically degenerated, region II was macroscopically normal but adjacent to regions I and III was the remaining normal articular surface. Thus, each extracted core was assigned to one of the three regions. A mixed effect model revealed that only the QP (p<0.0001) and IM (p<0.0001) were able to statistically discriminate the three regions. Effect size was higher for QP and IM than other assessments, indicating greater sensitivity to distinguish early degeneration of cartilage. When considering the mapping feature of the QP and IM techniques, it also revealed bilateral symmetry in a moderately similar distribution pattern between bilateral joints. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.


Changoor A.,Ecole Polytechnique de Montréal | Tran-Khanh N.,Ecole Polytechnique de Montréal | Methot S.,Piramal Healthcare Canada | Garon M.,Biomomentum Inc. | And 3 more authors.
Osteoarthritis and Cartilage | Year: 2011

Objectives: Collagen organization, a feature that is critical for cartilage load bearing and durability, is not adequately assessed in cartilage repair tissue by present histological scoring systems. Our objectives were to develop a new polarized light microscopy (PLM) score for collagen organization and to test its reliability. Design: This PLM score uses an ordinal scale of 0-5 to rate the extent that collagen network organization resembles that of young adult hyaline articular cartilage (score of 5) vs a totally disorganized tissue (score of 0). Inter-reader reliability was assessed using Intraclass Correlation Coefficients (ICC) for Agreement, calculated from scores of three trained readers who independently evaluated blinded sections obtained from normal (n= 4), degraded (n= 2) and repair (n= 22) human cartilage biopsies. Results: The PLM score succeeded in distinguishing normal, degraded and repair cartilages, where the latter displayed greater complexity in collagen structure. Excellent inter-reader reproducibility was found with ICCs for Agreement of 0.90 [ICC(2,1)] (lower boundary of the 95% confidence interval is 0.83) and 0.96 [ICC(2,3)] (lower boundary of the 95% confidence interval is 0.94), indicating the reliability of a single reader's scores and the mean of all three readers' scores, respectively. Conclusion: This PLM method offers a novel means for systematically evaluating collagen organization in repair cartilage. We propose that it be used to supplement current gold standard histological scoring systems for a more complete assessment of repair tissue quality. © 2010 Osteoarthritis Research Society International.


Changoor A.,Ecole Polytechnique de Montréal | Coutu J.P.,Ecole Polytechnique de Montréal | Garon M.,Biomomentum Inc. | Quenneville E.,Biomomentum Inc. | And 2 more authors.
Journal of Biomechanical Engineering | Year: 2011

Models of post-traumatic osteoarthritis where early degenerative changes can be monitored are valuable for assessing potential therapeutic strategies. Current methods for evaluating cartilage mechanical properties may not capture the low-grade cartilage changes expected at these earlier time points following injury. In this study, an explant model of cartilage injury was used to determine whether streaming potential measurements by manual indentation could detect cartilage changes immediately following mechanical impact and to compare their sensitivity to biomechanical tests. Impacts were delivered ex vivo, at one of three stress levels, to specific positions on isolated adult equine trochlea. Cartilage properties were assessed by streaming potential measurements, made pre- and post-impact using a commercially available arthroscopic device, and by stress relaxation tests in unconfined compression geometry of isolated cartilage disks, providing the streaming potential integral (SPI), fibril modulus (Ef), matrix modulus (Em), and permeability (k). Histological sections were stained with Safranin-O and adjacent unstained sections examined in polarized light microscopy. Impacts were low, 17.3 ± 2.7 MPa (n = 15), medium, 27.8 ± 8.5 MPa (n = 13), or high, 48.7 ± 12.1 MPa (n = 16), and delivered using a custom-built spring-loaded device with a rise time of approximately 1 ms. SPI was significantly reduced after medium (p = 0.006) and high (p < 0.001) impacts. Ef, representing collagen network stiffness, was significantly reduced in high impact samples only (p < 0.001 lateral trochlea, p = 0.042 medial trochlea), where permeability also increased (p = 0.003 lateral trochlea, p = 0.007 medial trochlea). Significant (p < 0.05, n = 68) moderate to strong correlations between SPI and Ef (r = 0.857), Em (r = 0.493), log(k) (r= -0.484), and cartilage thickness (r= -0.804) were detected. Effect sizes were higher for SPI than Ef, Em, and k, indicating greater sensitivity of electromechanical measurements to impact injury compared to purely biomechanical parameters. Histological changes due to impact were limited to the presence of superficial zone damage which increased with impact stress. Non-destructive streaming potential measurements were more sensitive to impact-related articular cartilage changes than biomechanical assessment of isolated samples using stress relaxation tests in unconfined compression geometry. Correlations between electromechanical and biomechanical methods further support the relationship between non-destructive electromechanical measurements and intrinsic cartilage properties. © 2011 American Society of Mechanical Engineers.


Tang Y.,McGill University | Zhou Y.,McGill University | Hoff T.,McGill University | Garon M.,Biomomentum Inc. | Zhao Y.F.,McGill University
Materials Science and Technology (United Kingdom) | Year: 2016

This study mainly evaluates the elastic modulusof 316stainless steel atticestructuresfabricatedvia binder jetting process. In this present research, both solid and lattice samples are designed and fabricated by binder jetting process for two different types of mechanical tests. Besides experimental study, a numerical model based on energy approach has been proposed to predict the effective elastic modulus of fabricated lattice samples. By comparing the calculated results of the proposed numerical model with the experimental results, the established model is proved to be validated. This numerical model can be used to determine the parameters of lattice structures fabricated by binder jetting process for desired mechanical properties. At the end, both advantages and disadvantages of the lattice structures fabricated by binder jetting process are analysed. Based on this analysis, the potential application and future research work are pointed out. © 2016 Institute of Materials, Minerals and Mining.


Sim S.,Ecole Polytechnique de Montréal | Sim S.,Biomomentum Inc. | Chevrier A.,Ecole Polytechnique de Montréal | Garon M.,Biomomentum Inc. | And 4 more authors.
Osteoarthritis and Cartilage | Year: 2014

Objective: The hand-held Arthro-BST™ device is used to map electromechanical properties of articular cartilage. The purpose of the study was to evaluate correlation of electromechanical properties with histological, biochemical and biomechanical properties of cartilage. Method: Electromechanical properties (quantitative parameter (QP)) of eight human distal femurs were mapped manually exvivo using the Arthro-BST (1 measure/site, 5s/measure, 3209 sites). Osteochondral cores were then harvested from different areas on the femurs and assessed with the Mankin histological score. Prior to histoprocessing, cores were tested in unconfined compression. A subset of the cores was analyzed with polarized light microscopy (PLM) to assess collagen structure. Biochemical assays were done on additional cores to obtain water content and glycosaminoglycan (GAG) content. The QP corresponding to each core was calculated by averaging all QPs collected within 6mm of the core center. Results: The electromechanical QP correlated strongly with both the Mankin score and the PLM score (r=0.73, P<0.0001 and r=-0.70, P<0.0001 respectively) thus accurately reflecting tissue quality and collagen architecture. Electromechanical QP also correlated strongly with biomechanical properties including fibril modulus (r=-0.76, P<0.0001), matrix modulus (r=-0.69, P<0.0001), and log of permeability (r=0.72, P<0.0001). The QP correlated weakly with GAG per wet weight and with water content (r=-0.50, P<0.0003 and r=0.39, P<0.006 respectively). Conclusion: Non-destructive electromechanical QP measurements correlate strongly with histological scores and biomechanical parameters providing a rapid and reliable assessment of articular cartilage quality. © 2014 Osteoarthritis Research Society International.


Trademark
Biomomentum Inc. | Date: 2012-07-17

Mechanical testers to measure with precision the mechanical properties of biological, chemical, and pharmaceutical samples, namely, stiffness, viscosity, poroelasticity, strength, swelling, adhesion and plasticity.


PubMed | Biomomentum Inc. and Ecole Polytechnique de Montréal
Type: Journal Article | Journal: Journal of biomechanics | Year: 2016

Electroarthrography (EAG) is a new technique for measuring electrical potentials appearing on the knee surface during loading that reflects cartilage quality and joint contact force. Our objective was to investigate the evolution of EAG signals during successive loading cycles. The study was conducted on 20 standing subjects who shifted their body weight to achieve knee loading. Their EAG signals were recorded during 10 successive loading cycles, and during a subsequent sequence of 10 cycles recorded after a 15min exercise period. Multiple linear regression models estimated the electro-mechanical ratio (EMR) interpreting the ability of cartilage to generate a certain potential for a given ground reaction force by taking into account this force and the center of pressure displacements during unipedal stance. The results showed that the EMR values slowly decreased with successive cycles: during the initial sequence, the correlation coefficients between EMR values and sequence numbers were significant at 3 of the 4 electrode sites (p<0.05); for the post-exercise sequence, the EMR values still decreased and were significantly lower than during the initial sequence (p<0.001). The reduction of EMR values could arise from muscle activity and habituation of the stretch reflex, and also from the time dependent electromechanical properties of cartilage. In conclusion, refraining from physical activity before the EAG measurements is important to improve measurement repeatability because of the EMR decrease. The electromechanical model confirmed the role of EAG as a natural sensor of the changes in the knee contact force and also improved EAG measurement accuracy.


Zhu L.,Ecole Polytechnique de Montréal | Garon M.,Biomomentum Inc. | Quenneville E.,Biomomentum Inc. | Buschmann M.D.,Ecole Polytechnique de Montréal | Savard P.,Ecole Polytechnique de Montréal
Journal of Biomechanics | Year: 2016

Electroarthrography (EAG) is a new technique for measuring electrical potentials appearing on the knee surface during loading that reflects cartilage quality and joint contact force. Our objective was to investigate the evolution of EAG signals during successive loading cycles. The study was conducted on 20 standing subjects who shifted their body weight to achieve knee loading. Their EAG signals were recorded during 10 successive loading cycles, and during a subsequent sequence of 10 cycles recorded after a 15 min exercise period. Multiple linear regression models estimated the electro-mechanical ratio (EMR) interpreting the ability of cartilage to generate a certain potential for a given ground reaction force by taking into account this force and the center of pressure displacements during unipedal stance. The results showed that the EMR values slowly decreased with successive cycles: during the initial sequence, the correlation coefficients between EMR values and sequence numbers were significant at 3 of the 4 electrode sites (p<0.05); for the post-exercise sequence, the EMR values still decreased and were significantly lower than during the initial sequence (p<0.001). The reduction of EMR values could arise from muscle activity and habituation of the stretch reflex, and also from the time dependent electromechanical properties of cartilage. In conclusion, refraining from physical activity before the EAG measurements is important to improve measurement repeatability because of the EMR decrease. The electromechanical model confirmed the role of EAG as a natural sensor of the changes in the knee contact force and also improved EAG measurement accuracy. © 2016 Elsevier Ltd


PubMed | Vital Systems, Biomomentum Inc. and Ecole Polytechnique de Montréal
Type: Journal Article | Journal: Osteoarthritis and cartilage | Year: 2014

The hand-held Arthro-BST device is used to map electromechanical properties of articular cartilage. The purpose of the study was to evaluate correlation of electromechanical properties with histological, biochemical and biomechanical properties of cartilage.Electromechanical properties (quantitative parameter (QP)) of eight human distal femurs were mapped manually exvivo using the Arthro-BST (1 measure/site, 5s/measure, 3209 sites). Osteochondral cores were then harvested from different areas on the femurs and assessed with the Mankin histological score. Prior to histoprocessing, cores were tested in unconfined compression. A subset of the cores was analyzed with polarized light microscopy (PLM) to assess collagen structure. Biochemical assays were done on additional cores to obtain water content and glycosaminoglycan (GAG) content. The QP corresponding to each core was calculated by averaging all QPs collected within 6mm of the core center.The electromechanical QP correlated strongly with both the Mankin score and the PLM score (r=0.73, P<0.0001 and r=-0.70, P<0.0001 respectively) thus accurately reflecting tissue quality and collagen architecture. Electromechanical QP also correlated strongly with biomechanical properties including fibril modulus (r=-0.76, P<0.0001), matrix modulus (r=-0.69, P<0.0001), and log of permeability (r=0.72, P<0.0001). The QP correlated weakly with GAG per wet weight and with water content (r=-0.50, P<0.0003 and r=0.39, P<0.006 respectively).Non-destructive electromechanical QP measurements correlate strongly with histological scores and biomechanical parameters providing a rapid and reliable assessment of articular cartilage quality.


PubMed | Vital Systems, Biomomentum Inc., Ecole Polytechnique de Montréal and University of Montréal
Type: | Journal: Journal of orthopaedic research : official publication of the Orthopaedic Research Society | Year: 2016

Recent advances in the development of new drugs to halt or even reverse the progression of Osteoarthritis at an early-stage requires new tools to detect early degeneration of articular cartilage. We investigated the ability of an electromechanical probe and an automated indentation technique to characterize entire human articular surfaces for rapid non-destructive discrimination between early degenerated and healthy articular cartilage. Human cadaveric asymptomatic articular surfaces (4 pairs of distal femurs and 4 pairs of tibial plateaus) were used. They were assessed ex vivo: macroscopically, electromechanically (maps of the electromechanical quantitative parameter, QP, reflecting streaming potentials), mechanically (maps of the instantaneous modulus, IM) and through cartilage thickness. Osteochondral cores were also harvested from healthy and degenerated regions for histological assessment, biochemical analyses and unconfined compression tests. The macroscopic visual assessment delimited three distinct regions on each articular surface: region I was macroscopically degenerated, region II was macroscopically normal but adjacent to region I and region III was the remaining normal articular surface. Thus, each extracted core was assigned to one of the three regions. A mixed effect model revealed that only the QP (p<0.0001) and IM (p<0.0001) were able to statistically discriminate the three regions. Effect size was higher for QP and IM than other assessments, indicating greater sensitivity to distinguish early degeneration of cartilage. When considering the mapping feature of the QP and IM techniques, it also revealed bilateral symmetry in a moderately similar distribution pattern between bilateral joints. This article is protected by copyright. All rights reserved.

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