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Jean-michel Laffosse - One of the best experts on this subject based on the ideXlab platform.
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Radiological validation of a fluoroscopic guided technique for femoral Implant Positioning during hip resurfacing
International Orthopaedics, 2013Co-Authors: Philippe Chiron, Régis Pailhé, Nicolas Reina, David Ancelin, Akash Sharma, Laurent Maubisson, Jean-michel LaffosseAbstract:Purpose The Positioning of the femoral cup in hip resurfacing is essential for the survival of the Implant. We described a technique in 2005 to position the femoral cup guided by fluoroscopy independent of the approach performed. The main objectives were to study the Positioning of the femoral components of the Implant and the accuracy of the technique. Methods Between 2003 and 2011 we conducted a prospective study of 160 consecutive hip resurfacings all operated with this fluoroscopic-guided technique. Three independent observers performed a radiographic analysis at the pre-operative planning stage and on postoperative radiographs using OsiriX software. The statistical analysis was based on comparison of two groups by Student’s t test. Results The entire Implant was positioned in valgus, with an average of 7.816° valgus ( p
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162 – REVISION TOTAL KNEE ARTHROPLASTY FOR MALROTATIONAL Implant Positioning
2011Co-Authors: Sanket Diwanji, Jean-michel Laffosse, Martin Lavigne, Pascal-andré VendittoliAbstract:Purpose: Even with modern ancillary and good surgical experience, rotational Implant Positioning is sometimes sub-optimal, leading to poor results. Except for obvious cases with patellar instability, the symptoms are often vague and non-contributive to the diagnosis of failure. This is why Implant malPositioning and particularly malrotational postioning remain an underestimated cause of failure after primary total knee arthroplasty (TKA). We report our experience with TKA revision for rotational malPositioning. Method: We retrospectively assessed the results of TKA revisions in 22 knees for malrotational Positioning. In all cases, malrotational Implant Positioning was confirmed by CT-scan according to Berger’s protocol. Results: Mean age was 66 years (47–74) at the time of the primary TKA. After the index procedure, all patients presented early anterior knee pain with patellar instability (tilt and subluxation in ten cases, and permanent patellar dislocation in two cases). Malrotational Positioning predominated on the tibial component with mean 23° internal rotation. Mean cumulative malrotation (tibial plus femur) was 22° internal rotation. All but four patients underwent femoral and tibial component revision. In two cases, only the tibial component was revised, and in two other cases, isolated transposition of the anterior tibial tuberosity was carried out. One was a failure, and finally underwent a successful full revision. At a mean follow-up of 30 months (12–60), we noted significant functional outcome improvement. One patient, who underwent a patellectomy previously at the index TKA procedure, had persistant anterior knee pain. No patient presented patellar instability. Conclusion: The diagnosis of Implant malrotational Positioning is sometimes difficult. The most common errors are tibial component Positioning. In case of suspicion of malrotational Positioning, protocolized CT-scan allows quick and simple diagnosis. If the malrotation is confirmed, TKA revision should be performed upon patient disability and severity of the symptoms. It is important not to delay the surgery, particularly in cases of patellofemoral dislocation because of the risks of developing soft tissue contractures resulting in a more difficult revision procedure.
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Anterolateral mini-invasive versus posterior mini-invasive approach for primary total hip replacement. Comparison of exposure and Implant Positioning
Archives of Orthopaedic and Trauma Surgery, 2008Co-Authors: Jean-michel Laffosse, Franck Accadbled, François Molinier, Philippe Chiron, Bensafi Hocine, J. PugetAbstract:Introduction We conducted a prospective study to compare the exposure and Implant Positioning in primary total hip replacement through the anterolateral minimally invasive (ALMI) approach versus the posterior minimally invasive (PMI) approach. Materials and methods We applied these techniques to 2 consecutive groups (33 and 43 patients, respectively) comparable preoperatively. All the patients received the same cementless stem and acetabular component. Results There were neither significant difference in femoral or acetabular component Positioning nor in limb-length discrepancy. Acetabular exposure was easy through the ALMI approach. Femoral exposure was more difficult as fractures of the trochanter and femoral perforation in our study show. Conclusion For us, exposure and Implant Positioning through the ALMI approach and the PMI approach are comparable and reliable. However, we recommend caution during the initial learning curve in osteoporotic patients due to the higher rate of peroperative complications for the ALMI approach.
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Anterolateral mini-invasive versus posterior mini-invasive approach for primary total hip replacement. Comparison of exposure and Implant Positioning
Archives of Orthopaedic and Trauma Surgery, 2007Co-Authors: Jean-michel Laffosse, Franck Accadbled, François Molinier, Philippe Chiron, Bensafi Hocine, J. PugetAbstract:INTRODUCTION: We conducted a prospective study to compare the exposure and Implant Positioning in primary total hip replacement through the anterolateral minimally invasive (ALMI) approach versus the posterior minimally invasive (PMI) approach. MATERIALS AND METHODS: We applied these techniques to 2 consecutive groups (33 and 43 patients, respectively) comparable preoperatively. All the patients received the same cementless stem and acetabular component. RESULTS: There were neither significant difference in femoral or acetabular component Positioning nor in limb-length discrepancy. Acetabular exposure was easy through the ALMI approach. Femoral exposure was more difficult as fractures of the trochanter and femoral perforation in our study show. CONCLUSION: For us, exposure and Implant Positioning through the ALMI approach and the PMI approach are comparable and reliable. However, we recommend caution during the initial learning curve in osteoporotic patients due to the higher rate of peroperative complications for the ALMI approach.
Martin Browne - One of the best experts on this subject based on the ideXlab platform.
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A839. A NOVEL COMPUTATIONAL TOOL FOR THE ANALYSIS OF Implant Positioning EFFECTS IN CEMENTLESS TOTAL HIP REPLACEMENTS
2011Co-Authors: M.t. Bah, Prasanth B. Nair, Martin BrowneAbstract:Implant Positioning is a critical factor in assuring the primary stability of cementless Total Hip Replacements (THRs). Although it is under the direct control of surgeons, finding the optimal Implant position and achieving a perfect fit remain a challenge even with the advent of computer navigation. Placement of the femoral stem in an excessive ante/retroversion or varus/valgus orientation can be detrimental to the performance of THR. To determine the effect of such malalignment, finite element (FE) computer modelling is often used. However, this can be time consuming since FE meshes must be repeatedly generated and solved each time for a range of defined Implant positions. In the present study, a mesh morphing technique is developed for the automatic generation of FE models of the Implanted femur; in this way, many Implant orientations can be investigated in a single analysis. An average femur geometry generated from a CT scan population of 13 male and 8 female patients aged between 43 and 84 years was considered. The femur was virtually Implanted with the Furlong HAC titanium alloy stem (JRI Ltd, Sheffield, UK) and placed in the medullary canal in a baseline neutral nominal position. The head of the femur was then removed and both femur and Implant volumes were joined together to form a single piece that was exported into ANSYS11 ICEM CFD (ANSYS Inc., 2008) for meshing. To adequately replicate Implant ante/retroversion, varus/valgus or anterior/posterior orientations, the rigid body displacement of the Implant was controlled by three rotations with respect to a local coordinate system. One hundred different Implant positions were analysed and the quality of the morphed meshes analysed for consistency. To check the morphed meshes, corresponding models were generated individually by re-Positioning the Implant in the femur. Selected models were solved to predict the strain distribution in the bone and the boneImplant relative micromovements under joint and muscle loading. A good agreement was found for bone strains and Implant micromotions between the morphed models and their individually run counterparts. In the postprocessing stage further metrics were analysed to corroborate the findings of the morphed and individually run models. These included: average and maximum strains in bone interface area and its entire volume, percentage of bone interface area and its volume strained up to and beyond 0.7%; Implant average and maximum micromotions and finally percentages of Implant area undergoing reported critical micromotions of 50 μm, 100 μm and 150 μm for bone in growth. Excellent correlation was observed in all cases. In conclusion, the proposed technique allowed an automatic generation of FE meshes of the Implanted femur as the Implant position varies; the required computational resources were considerably reduced and the biomechanical response was evaluated. This model forms a good basis for the development of a tool for multiple statistical analyses of the effects of Implant orientation in pre-clinical studies.
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efficient computational method for assessing the effects of Implant Positioning in cementless total hip replacements
Journal of Biomechanics, 2011Co-Authors: M.t. Bah, Prasanth B. Nair, Mark Taylor, Martin BrowneAbstract:The present work describes a statistical investigation into the effects of Implant Positioning on the initial stability of a cementless total hip replacement (THR). Mesh morphing was combined with design of computer experiments to automatically construct Finite Element (FE) meshes for a range of pre-defined femur-Implant configurations and to predict Implant micromotions under joint contact and muscle loading. Computed micromotions, in turn, are postprocessed using a Bayesian approach to: (a) compute the main effects of Implant orientation angles, (b) predict the sensitivities of the considered Implant performance metrics with respect to Implant ante-retroversion, varus-valgus and antero-posterior orientation angles and (c) identify Implant positions that maximise and minimise each metric. It is found that the percentage of Implant area with micromotion greater than 50 μm, average and maximum micromotions are all more sensitive to antero-posterior orientation than ante-retroversion and varus-valgus orientation. Sensitivities, combined with the main effect results, suggest that bone is less likely to grow if the Implant is increasingly moved from the neutral position towards the anterior part of the femur, where the highest micromotions occur. The computed Implant best position leads to a percentage of Implant area with micromotion greater than 50 μm of 1.14 when using this metric compared to 14.6 and 5.95 in the worst and neutrally positioned Implant cases. In contrast, when the Implant average/maximum micromotion is used to assess the THR performance, the Implant best position corresponds to average/maximum micromotion of 9 μm/59 μm, compared to 20 μm/114 μm and 13 μm/71 μm in the worst and neutral positions, respectively. The proposed computational framework can be extended further to study the effects of uncertainty and variability in anatomy, bone mechanical properties, loading or bone-Implant interface contact conditions.
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Effects of Implant Positioning in cementless total hip replacements
Computer Methods in Biomechanics and Biomedical Engineering, 2011Co-Authors: M.t. Bah, Martin Browne, Philippe Young, R. Bryan, V. Bui XuanAbstract:Cementless Total Hip Replacements (THRs) are required to approximate as closely as possible the natural joint function for the full postoperative life span. Unfortunately, Implant Positioning is not always perfect due to the curved shape of the thigh bone and the stem is often straight [1]. Surgeons need to decide on three orientation angles that directly influence the success of a cementless THR: the antero/retro version of the femur neck orientation, Implant varus/valgus placement and anterior/posterior orientation. Ideally, to account for Positioning variability, all possible Implant orientations should be analysed and simulated. Unfortunately, this would be an intractable task if it was attempted experimentally, and computational simulations are often applied to reduce this burden. However, even in computational pre-clinical assessments of Implant primary stability, this is a huge task, as it involves generating a new mesh for each new position and solving the corresponding Finite Element (FE) problem [2]. In the current work, this problem is addressed using a mesh morphing-based framework that can efficiently assess the effects of Implant Positioning.
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Rapid analysis of Implant Positioning effects in cementless total hip replacements
2010Co-Authors: M.t. Bah, Prasanth B. Nair, Martin BrowneAbstract:Implant Positioning plays an important role in the success of cementless THRs in the early postoperative stage. Variability in Positioning might be inevitable even with better pre-operative planning softwares or computer navigation. Combining multiple CAD operations and Finite Element (FE) simulations can help to capture variability effects. In the present study, FE meshes of the Implanted femur were automatically generated for a range of pre-defined femur-Implant configurations. Predicted micromovements at the femur-Implant interface were then used to construct surrogate models to (a) compute the sensitivities of three biomechanical metrics to Implant orientations and (b) identify the best and worst Implant positions
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Mesh morphing for finite element analysis of Implant Positioning in cementless total hip replacements
Medical engineering & physics, 2009Co-Authors: M.t. Bah, Prasanth B. Nair, Martin BrowneAbstract:Finite element (FE) analysis of the effect of Implant Positioning on the performance of cementless total hip replacements (THRs) requires the generation of multiple meshes to account for Positioning variability. This process can be labour intensive and time consuming as CAD operations are needed each time a specific orientation is to be analysed. In the present work, a mesh morphing technique is developed to automate the model generation process. The volume mesh of a baseline femur with the Implant in a nominal position is deformed as the prosthesis location is varied. A virtual deformation field, obtained by solving a linear elasticity problem with appropriate boundary conditions, is applied. The effectiveness of the technique is evaluated using two metrics: the percentages of morphed elements exceeding an aspect ratio of 20 and an angle of 165° between the adjacent edges of each tetrahedron. Results show that for 100 different Implant positions, the first and second metrics never exceed 3% and 3.5%, respectively. To further validate the proposed technique, FE contact analyses are conducted using three selected morphed models to predict the strain distribution in the bone and the Implant micromotion under joint and muscle loading. The entire bone strain distribution is well captured and both percentages of bone volume with strain exceeding 0.7% and bone average strains are accurately computed. The results generated from the morphed mesh models correlate well with those for models generated from scratch, increasing confidence in the methodology. This morphing technique forms an accurate and efficient basis for FE based Implant orientation and stability analysis of cementless hip replacements.
Philippe Chiron - One of the best experts on this subject based on the ideXlab platform.
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Radiological validation of a fluoroscopic guided technique for femoral Implant Positioning during hip resurfacing
International Orthopaedics, 2013Co-Authors: Philippe Chiron, Régis Pailhé, Nicolas Reina, David Ancelin, Akash Sharma, Laurent Maubisson, Jean-michel LaffosseAbstract:Purpose The Positioning of the femoral cup in hip resurfacing is essential for the survival of the Implant. We described a technique in 2005 to position the femoral cup guided by fluoroscopy independent of the approach performed. The main objectives were to study the Positioning of the femoral components of the Implant and the accuracy of the technique. Methods Between 2003 and 2011 we conducted a prospective study of 160 consecutive hip resurfacings all operated with this fluoroscopic-guided technique. Three independent observers performed a radiographic analysis at the pre-operative planning stage and on postoperative radiographs using OsiriX software. The statistical analysis was based on comparison of two groups by Student’s t test. Results The entire Implant was positioned in valgus, with an average of 7.816° valgus ( p
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Anterolateral mini-invasive versus posterior mini-invasive approach for primary total hip replacement. Comparison of exposure and Implant Positioning
Archives of Orthopaedic and Trauma Surgery, 2008Co-Authors: Jean-michel Laffosse, Franck Accadbled, François Molinier, Philippe Chiron, Bensafi Hocine, J. PugetAbstract:Introduction We conducted a prospective study to compare the exposure and Implant Positioning in primary total hip replacement through the anterolateral minimally invasive (ALMI) approach versus the posterior minimally invasive (PMI) approach. Materials and methods We applied these techniques to 2 consecutive groups (33 and 43 patients, respectively) comparable preoperatively. All the patients received the same cementless stem and acetabular component. Results There were neither significant difference in femoral or acetabular component Positioning nor in limb-length discrepancy. Acetabular exposure was easy through the ALMI approach. Femoral exposure was more difficult as fractures of the trochanter and femoral perforation in our study show. Conclusion For us, exposure and Implant Positioning through the ALMI approach and the PMI approach are comparable and reliable. However, we recommend caution during the initial learning curve in osteoporotic patients due to the higher rate of peroperative complications for the ALMI approach.
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Anterolateral mini-invasive versus posterior mini-invasive approach for primary total hip replacement. Comparison of exposure and Implant Positioning
Archives of Orthopaedic and Trauma Surgery, 2007Co-Authors: Jean-michel Laffosse, Franck Accadbled, François Molinier, Philippe Chiron, Bensafi Hocine, J. PugetAbstract:INTRODUCTION: We conducted a prospective study to compare the exposure and Implant Positioning in primary total hip replacement through the anterolateral minimally invasive (ALMI) approach versus the posterior minimally invasive (PMI) approach. MATERIALS AND METHODS: We applied these techniques to 2 consecutive groups (33 and 43 patients, respectively) comparable preoperatively. All the patients received the same cementless stem and acetabular component. RESULTS: There were neither significant difference in femoral or acetabular component Positioning nor in limb-length discrepancy. Acetabular exposure was easy through the ALMI approach. Femoral exposure was more difficult as fractures of the trochanter and femoral perforation in our study show. CONCLUSION: For us, exposure and Implant Positioning through the ALMI approach and the PMI approach are comparable and reliable. However, we recommend caution during the initial learning curve in osteoporotic patients due to the higher rate of peroperative complications for the ALMI approach.
M.t. Bah - One of the best experts on this subject based on the ideXlab platform.
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A839. A NOVEL COMPUTATIONAL TOOL FOR THE ANALYSIS OF Implant Positioning EFFECTS IN CEMENTLESS TOTAL HIP REPLACEMENTS
2011Co-Authors: M.t. Bah, Prasanth B. Nair, Martin BrowneAbstract:Implant Positioning is a critical factor in assuring the primary stability of cementless Total Hip Replacements (THRs). Although it is under the direct control of surgeons, finding the optimal Implant position and achieving a perfect fit remain a challenge even with the advent of computer navigation. Placement of the femoral stem in an excessive ante/retroversion or varus/valgus orientation can be detrimental to the performance of THR. To determine the effect of such malalignment, finite element (FE) computer modelling is often used. However, this can be time consuming since FE meshes must be repeatedly generated and solved each time for a range of defined Implant positions. In the present study, a mesh morphing technique is developed for the automatic generation of FE models of the Implanted femur; in this way, many Implant orientations can be investigated in a single analysis. An average femur geometry generated from a CT scan population of 13 male and 8 female patients aged between 43 and 84 years was considered. The femur was virtually Implanted with the Furlong HAC titanium alloy stem (JRI Ltd, Sheffield, UK) and placed in the medullary canal in a baseline neutral nominal position. The head of the femur was then removed and both femur and Implant volumes were joined together to form a single piece that was exported into ANSYS11 ICEM CFD (ANSYS Inc., 2008) for meshing. To adequately replicate Implant ante/retroversion, varus/valgus or anterior/posterior orientations, the rigid body displacement of the Implant was controlled by three rotations with respect to a local coordinate system. One hundred different Implant positions were analysed and the quality of the morphed meshes analysed for consistency. To check the morphed meshes, corresponding models were generated individually by re-Positioning the Implant in the femur. Selected models were solved to predict the strain distribution in the bone and the boneImplant relative micromovements under joint and muscle loading. A good agreement was found for bone strains and Implant micromotions between the morphed models and their individually run counterparts. In the postprocessing stage further metrics were analysed to corroborate the findings of the morphed and individually run models. These included: average and maximum strains in bone interface area and its entire volume, percentage of bone interface area and its volume strained up to and beyond 0.7%; Implant average and maximum micromotions and finally percentages of Implant area undergoing reported critical micromotions of 50 μm, 100 μm and 150 μm for bone in growth. Excellent correlation was observed in all cases. In conclusion, the proposed technique allowed an automatic generation of FE meshes of the Implanted femur as the Implant position varies; the required computational resources were considerably reduced and the biomechanical response was evaluated. This model forms a good basis for the development of a tool for multiple statistical analyses of the effects of Implant orientation in pre-clinical studies.
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efficient computational method for assessing the effects of Implant Positioning in cementless total hip replacements
Journal of Biomechanics, 2011Co-Authors: M.t. Bah, Prasanth B. Nair, Mark Taylor, Martin BrowneAbstract:The present work describes a statistical investigation into the effects of Implant Positioning on the initial stability of a cementless total hip replacement (THR). Mesh morphing was combined with design of computer experiments to automatically construct Finite Element (FE) meshes for a range of pre-defined femur-Implant configurations and to predict Implant micromotions under joint contact and muscle loading. Computed micromotions, in turn, are postprocessed using a Bayesian approach to: (a) compute the main effects of Implant orientation angles, (b) predict the sensitivities of the considered Implant performance metrics with respect to Implant ante-retroversion, varus-valgus and antero-posterior orientation angles and (c) identify Implant positions that maximise and minimise each metric. It is found that the percentage of Implant area with micromotion greater than 50 μm, average and maximum micromotions are all more sensitive to antero-posterior orientation than ante-retroversion and varus-valgus orientation. Sensitivities, combined with the main effect results, suggest that bone is less likely to grow if the Implant is increasingly moved from the neutral position towards the anterior part of the femur, where the highest micromotions occur. The computed Implant best position leads to a percentage of Implant area with micromotion greater than 50 μm of 1.14 when using this metric compared to 14.6 and 5.95 in the worst and neutrally positioned Implant cases. In contrast, when the Implant average/maximum micromotion is used to assess the THR performance, the Implant best position corresponds to average/maximum micromotion of 9 μm/59 μm, compared to 20 μm/114 μm and 13 μm/71 μm in the worst and neutral positions, respectively. The proposed computational framework can be extended further to study the effects of uncertainty and variability in anatomy, bone mechanical properties, loading or bone-Implant interface contact conditions.
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Effects of Implant Positioning in cementless total hip replacements
Computer Methods in Biomechanics and Biomedical Engineering, 2011Co-Authors: M.t. Bah, Martin Browne, Philippe Young, R. Bryan, V. Bui XuanAbstract:Cementless Total Hip Replacements (THRs) are required to approximate as closely as possible the natural joint function for the full postoperative life span. Unfortunately, Implant Positioning is not always perfect due to the curved shape of the thigh bone and the stem is often straight [1]. Surgeons need to decide on three orientation angles that directly influence the success of a cementless THR: the antero/retro version of the femur neck orientation, Implant varus/valgus placement and anterior/posterior orientation. Ideally, to account for Positioning variability, all possible Implant orientations should be analysed and simulated. Unfortunately, this would be an intractable task if it was attempted experimentally, and computational simulations are often applied to reduce this burden. However, even in computational pre-clinical assessments of Implant primary stability, this is a huge task, as it involves generating a new mesh for each new position and solving the corresponding Finite Element (FE) problem [2]. In the current work, this problem is addressed using a mesh morphing-based framework that can efficiently assess the effects of Implant Positioning.
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Rapid analysis of Implant Positioning effects in cementless total hip replacements
2010Co-Authors: M.t. Bah, Prasanth B. Nair, Martin BrowneAbstract:Implant Positioning plays an important role in the success of cementless THRs in the early postoperative stage. Variability in Positioning might be inevitable even with better pre-operative planning softwares or computer navigation. Combining multiple CAD operations and Finite Element (FE) simulations can help to capture variability effects. In the present study, FE meshes of the Implanted femur were automatically generated for a range of pre-defined femur-Implant configurations. Predicted micromovements at the femur-Implant interface were then used to construct surrogate models to (a) compute the sensitivities of three biomechanical metrics to Implant orientations and (b) identify the best and worst Implant positions
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Mesh morphing for finite element analysis of Implant Positioning in cementless total hip replacements
Medical engineering & physics, 2009Co-Authors: M.t. Bah, Prasanth B. Nair, Martin BrowneAbstract:Finite element (FE) analysis of the effect of Implant Positioning on the performance of cementless total hip replacements (THRs) requires the generation of multiple meshes to account for Positioning variability. This process can be labour intensive and time consuming as CAD operations are needed each time a specific orientation is to be analysed. In the present work, a mesh morphing technique is developed to automate the model generation process. The volume mesh of a baseline femur with the Implant in a nominal position is deformed as the prosthesis location is varied. A virtual deformation field, obtained by solving a linear elasticity problem with appropriate boundary conditions, is applied. The effectiveness of the technique is evaluated using two metrics: the percentages of morphed elements exceeding an aspect ratio of 20 and an angle of 165° between the adjacent edges of each tetrahedron. Results show that for 100 different Implant positions, the first and second metrics never exceed 3% and 3.5%, respectively. To further validate the proposed technique, FE contact analyses are conducted using three selected morphed models to predict the strain distribution in the bone and the Implant micromotion under joint and muscle loading. The entire bone strain distribution is well captured and both percentages of bone volume with strain exceeding 0.7% and bone average strains are accurately computed. The results generated from the morphed mesh models correlate well with those for models generated from scratch, increasing confidence in the methodology. This morphing technique forms an accurate and efficient basis for FE based Implant orientation and stability analysis of cementless hip replacements.
Jean-noël Argenson - One of the best experts on this subject based on the ideXlab platform.
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Better Implant Positioning and Clinical Outcomes With a Morphometric Unicompartmental Knee Arthroplasty. Results of a Retrospective, Matched-Controlled Study
Journal of Arthroplasty, 2019Co-Authors: Jean-charles Escudier, Christophe Jacquet, Xavier Flecher, Sebastien Parratte, Matthieu Ollivier, Jean-noël ArgensonAbstract:Background: During medial unicompartmental knee arthroplasty (UKA), tibial tray Implantation requires compromise between bone coverage and rotational position. It was hypothesized that morphometric tibial tray (MTT) would improve Implant Positioning and subsequently clinical outcomes as compared to symmetric tibial tray (STT). Methods: A total of 106 patients who underwent medial UKA in our department between January 2017 and March 2018 were included matched on gender and age (53 in each group). Inclusion criteria were symptomatic medial femorotibial osteoarthritis, functional anterior cruciate ligament, primary arthritis, or osteonecrosis. Rotation of the tibial Implant, tibial bone coverage, medial and posterior overhang were assessed with a postoperative computed tomography scan. The Knee Society Score (KSS), the Knee injury and Osteoarthritis Outcome Score Short Form (KOOS SF), and the quality of life score EuroQoL 5-Dimensions 3-Levels (EQ5D3L) were assessed at a minimum of 1-year follow-up. Results: Implants of the STT group exhibited more external rotation (6.3 ± 4.02 vs 4.6 ± 3.59 ; P ¼ .04), and medial and posterior overhang >3 mm (35% vs 0% and 22% vs 0%; P < .0001) but no difference for tibial bone coverage (97.3% ± 11.35% vs 94.7% ± 10.89%; P ¼ .23). Global KSS (188.6 ± 6.6 vs 175.2 ± 31.7; P < .01), KOOS SF (16.9 ± 6.1 vs 22.5 ± 11.8; P < .003), and EQ5D3L (1 ± 0.1 vs 0.9 ± 0.2; P < .001) were higher in MTT group. According to the multivariate analysis, MTT had a positive independent effect on the KSS, KOOS SF, and EQ5D3L. Conclusion: The use of an MTT in medial UKA allowed better Implant Positioning when decreasing the rate of overhang; superior short-term clinical outcomes were found as compared to STT.
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Better Implant Positioning and Clinical Outcomes With a Morphometric Unicompartmental Knee Arthroplasty. Results of a Retrospective, Matched-Controlled Study.
The Journal of arthroplasty, 2019Co-Authors: Jean-charles Escudier, Christophe Jacquet, Xavier Flecher, Sebastien Parratte, Matthieu Ollivier, Jean-noël ArgensonAbstract:Abstract Background During medial unicompartmental knee arthroplasty (UKA), tibial tray Implantation requires compromise between bone coverage and rotational position. It was hypothesized that morphometric tibial tray (MTT) would improve Implant Positioning and subsequently clinical outcomes as compared to symmetric tibial tray (STT). Methods A total of 106 patients who underwent medial UKA in our department between January 2017 and March 2018 were included matched on gender and age (53 in each group). Inclusion criteria were symptomatic medial femorotibial osteoarthritis, functional anterior cruciate ligament, primary arthritis, or osteonecrosis. Rotation of the tibial Implant, tibial bone coverage, medial and posterior overhang were assessed with a postoperative computed tomography scan. The Knee Society Score (KSS), the Knee injury and Osteoarthritis Outcome Score Short Form (KOOS SF), and the quality of life score EuroQoL 5-Dimensions 3-Levels (EQ5D3L) were assessed at a minimum of 1-year follow-up. Results Implants of the STT group exhibited more external rotation (6.3° ± 4.02° vs 4.6° ± 3.59°; P = .04), and medial and posterior overhang >3 mm (35% vs 0% and 22% vs 0%; P Conclusion The use of an MTT in medial UKA allowed better Implant Positioning when decreasing the rate of overhang; superior short-term clinical outcomes were found as compared to STT.
