The Experts below are selected from a list of 8700 Experts worldwide ranked by ideXlab platform
Stephen K Aoki - One of the best experts on this subject based on the ideXlab platform.
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femoral neck fracture fixation with a medial Buttress plate that led to impingement with hip flexion a case report
Journal of Bone and Joint Surgery American Volume, 2019Co-Authors: Lucas S Marchand, Michael R Karns, Thomas F Higgins, Stephen K AokiAbstract:CASE A 47-year-old man with an isolated femoral neck fracture was treated with open reduction and internal fixation with a medial femoral neck Buttress plate and a dynamic hip screw. Union was achieved without osteonecrosis of the femoral head. However, hip arthroscopy that was performed for persistent hip pain following the fracture union revealed an intra-articular impingement of the Buttress plate and a substantial anterior acetabular chondral injury. CONCLUSIONS To our knowledge, this is the first reported complication associated with the application of a medial Buttress plate for a femoral neck fracture. This case report may help surgeons who employ this technique to avoid a similar complication.
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femoral neck fracture fixation with a medial Buttress plate that led to impingement with hip flexion a case report
Journal of Bone and Joint Surgery American Volume, 2019Co-Authors: Lucas S Marchand, Michael R Karns, Thomas F Higgins, Stephen K AokiAbstract:CASE A 47-year-old man with an isolated femoral neck fracture was treated with open reduction and internal fixation with a medial femoral neck Buttress plate and a dynamic hip screw. Union was achieved without osteonecrosis of the femoral head. However, hip arthroscopy that was performed for persistent hip pain following the fracture union revealed an intra-articular impingement of the Buttress plate and a substantial anterior acetabular chondral injury. CONCLUSIONS To our knowledge, this is the first reported complication associated with the application of a medial Buttress plate for a femoral neck fracture. This case report may help surgeons who employ this technique to avoid a similar complication.
Piogo Hsieh - One of the best experts on this subject based on the ideXlab platform.
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investigation of the integrated retaining system to limit deformations induced by deep excavation
Acta Geotechnica, 2018Co-Authors: Aswin Lim, Piogo HsiehAbstract:A series of three-dimensional finite element analyses of deep excavations with the integrated system between Buttress walls and diaphragm walls was conducted to investigate the effect of the Buttress wall intervals, treatments, locations, height, and thickness on limiting deformations induced by deep excavation. The integrated retaining system was formed by maintaining Buttress walls when soil was excavated. The wall deflection control mechanism of the integrated retaining system mainly came from the combined stiffness between the Buttress wall and the diaphragm wall. In addition, the ground settlement control mechanism came from the combined stiffness between the Buttress wall and the diaphragm wall, and the frictional resistance between the Buttress wall and the surrounding soil. For achieving 50% reduction in the wall deflection and the ground surface settlement, the length and intervals of Buttress walls that were applied to the integrated retaining system were at least 4 and 8 m, respectively. When the deflection at the diaphragm wall head was well restrained, for example, by the floor slab, the position of the Buttress wall head could be located at a depth the diaphragm wall starts to bulge out. In such a case, the performance between the full height and limited height of Buttress walls was quite close. Furthermore, a new well-documented excavation project was analyzed to verify the performance of the integrated retaining system. Results showed that the integrated retaining system worked excellently if the joints between Buttress walls and diaphragm walls were constructed properly.
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efficiency of excavations with Buttress walls in reducing the deflection of the diaphragm wall
Acta Geotechnica, 2016Co-Authors: Piogo Hsieh, Weiha HsiehAbstract:Installation of Buttress walls against diaphragm walls has been used as an alternative measure for the protection of adjacent buildings during excavation, but their mechanism in reducing movements has not yet been fully understood. This study performs three-dimensional finite element analyses of two excavation case histories, one in clay with T-shape Buttress walls and another in dominant sand with rectangular Buttress walls, to establish analysis model. Then, a series of parametric study were performed by varying soil types, types and length of Buttress walls based on the above-mentioned excavations. Results show that the mechanism of Buttress walls in reducing wall deflections mainly came from the frictional resistance between the side surface of Buttress wall and adjacent soil rather than from the combined bending stiffness from diaphragm and Buttress walls. The Buttress wall with a length <2.0 m had a poor effect in reducing the wall deflection because the soil adjacent to the Buttress wall had almost the same amount of movement as the Buttress wall, causing the frictional resistance little mobilized. Since the frictional resistance of Buttress walls in a deep excavation has fully been mobilized prior to the final excavation depth, the efficiency of Buttress walls in reducing the wall deflection in a deep excavation was much less than that in a shallow excavation. Rectangular shape of Buttress walls was of a better effect than T-shape in the shallow excavation because frictional resistance between Buttress walls and adjacent soil played a major role in reducing the wall deflection rather than bearing resistance of the flange. When the excavation went deeper, the difference in reducing the wall deflection between the R-shape and T-shape became small.
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evaluation of Buttress wall shapes to limit movements induced by deep excavation
Computers and Geotechnics, 2016Co-Authors: Aswin Lim, Piogo HsiehAbstract:Abstract Three-dimension finite element analyses of deep excavations with Buttress walls were performed to evaluate the effect of Buttress wall shapes on limiting movements induced by deep excavation. Results showed that a combination of the rectangular and the capital L-letter shapes (RL-shape) yielded the greatest performance in reducing wall deflections and ground surface settlements. The main deformation-control mechanism mainly came from the horizontal and vertical frictional resistances of Buttress walls against adjacent soils which were pushed by wall deflections and the soil heave at the excavation bottom, respectively. Besides, the RL-shape Buttress walls were successfully verified through a well-documented case history.
Lucas S Marchand - One of the best experts on this subject based on the ideXlab platform.
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femoral neck fracture fixation with a medial Buttress plate that led to impingement with hip flexion a case report
Journal of Bone and Joint Surgery American Volume, 2019Co-Authors: Lucas S Marchand, Michael R Karns, Thomas F Higgins, Stephen K AokiAbstract:CASE A 47-year-old man with an isolated femoral neck fracture was treated with open reduction and internal fixation with a medial femoral neck Buttress plate and a dynamic hip screw. Union was achieved without osteonecrosis of the femoral head. However, hip arthroscopy that was performed for persistent hip pain following the fracture union revealed an intra-articular impingement of the Buttress plate and a substantial anterior acetabular chondral injury. CONCLUSIONS To our knowledge, this is the first reported complication associated with the application of a medial Buttress plate for a femoral neck fracture. This case report may help surgeons who employ this technique to avoid a similar complication.
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femoral neck fracture fixation with a medial Buttress plate that led to impingement with hip flexion a case report
Journal of Bone and Joint Surgery American Volume, 2019Co-Authors: Lucas S Marchand, Michael R Karns, Thomas F Higgins, Stephen K AokiAbstract:CASE A 47-year-old man with an isolated femoral neck fracture was treated with open reduction and internal fixation with a medial femoral neck Buttress plate and a dynamic hip screw. Union was achieved without osteonecrosis of the femoral head. However, hip arthroscopy that was performed for persistent hip pain following the fracture union revealed an intra-articular impingement of the Buttress plate and a substantial anterior acetabular chondral injury. CONCLUSIONS To our knowledge, this is the first reported complication associated with the application of a medial Buttress plate for a femoral neck fracture. This case report may help surgeons who employ this technique to avoid a similar complication.
Peifu Tang - One of the best experts on this subject based on the ideXlab platform.
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medial anatomical Buttress plate in treating displaced femoral neck fracture a finite element analysis
Injury-international Journal of The Care of The Injured, 2019Co-Authors: Jia Li, Licheng Zhang, Hua Chen, Peifu TangAbstract:Abstract Background Displaced femoral neck fractures in young adults are most likely to result from high energy trauma that causes a vertically-oriented shearing injury through the femoral neck. The optimal strategy for treatment of displaced femoral neck fractures remains an unsolved challenge in orthopedic surgery. Methods our group has previously designed a medial anatomical Buttress plate (MABP) based on the analysis of the computed tomography (CT) data of anatomical structures derived from a large sample population. In this study, finite element analyses (FEA) were carried out to compare the outcomes of the combination of our MABP with cannulated screws to those of the combination of tubular plate with cannulated screws, and to those of using cannulated screws alone. Results MABP resulted in a more stable fixation as compared to the other two approaches, with respect to the femur and the stress distributions, stress peaks, and Z axis displacements. Conclusions The FEA encouraged us that addition of a medial Buttress plate not only achieved superior medial Buttress stability but also achieves superior performance because it perfectly fits with the existing anatomic structure of medial femoral neck. The results from our study may provide references for clinical decision making in dealing with such patients.
Aswin Lim - One of the best experts on this subject based on the ideXlab platform.
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investigation of the integrated retaining system to limit deformations induced by deep excavation
Acta Geotechnica, 2018Co-Authors: Aswin Lim, Piogo HsiehAbstract:A series of three-dimensional finite element analyses of deep excavations with the integrated system between Buttress walls and diaphragm walls was conducted to investigate the effect of the Buttress wall intervals, treatments, locations, height, and thickness on limiting deformations induced by deep excavation. The integrated retaining system was formed by maintaining Buttress walls when soil was excavated. The wall deflection control mechanism of the integrated retaining system mainly came from the combined stiffness between the Buttress wall and the diaphragm wall. In addition, the ground settlement control mechanism came from the combined stiffness between the Buttress wall and the diaphragm wall, and the frictional resistance between the Buttress wall and the surrounding soil. For achieving 50% reduction in the wall deflection and the ground surface settlement, the length and intervals of Buttress walls that were applied to the integrated retaining system were at least 4 and 8 m, respectively. When the deflection at the diaphragm wall head was well restrained, for example, by the floor slab, the position of the Buttress wall head could be located at a depth the diaphragm wall starts to bulge out. In such a case, the performance between the full height and limited height of Buttress walls was quite close. Furthermore, a new well-documented excavation project was analyzed to verify the performance of the integrated retaining system. Results showed that the integrated retaining system worked excellently if the joints between Buttress walls and diaphragm walls were constructed properly.
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evaluation of Buttress wall shapes to limit movements induced by deep excavation
Computers and Geotechnics, 2016Co-Authors: Aswin Lim, Piogo HsiehAbstract:Abstract Three-dimension finite element analyses of deep excavations with Buttress walls were performed to evaluate the effect of Buttress wall shapes on limiting movements induced by deep excavation. Results showed that a combination of the rectangular and the capital L-letter shapes (RL-shape) yielded the greatest performance in reducing wall deflections and ground surface settlements. The main deformation-control mechanism mainly came from the horizontal and vertical frictional resistances of Buttress walls against adjacent soils which were pushed by wall deflections and the soil heave at the excavation bottom, respectively. Besides, the RL-shape Buttress walls were successfully verified through a well-documented case history.
