The Experts below are selected from a list of 29184 Experts worldwide ranked by ideXlab platform
Robert L. Barrack - One of the best experts on this subject based on the ideXlab platform.
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dislocation after total hip arthroplasty Implant Design and orientation
Journal of The American Academy of Orthopaedic Surgeons, 2003Co-Authors: Robert L. BarrackAbstract:Implant Design and positioning are important factors in maintaining stability and minimizing dislocation after total hip arthroplasty. Although the advent of modular femoral stems and acetabular Implants increased the number of head, neck, and liner Designs, the features of recent Designs can cause intra-articular prosthetic impingement within the arc of motion required for normal daily activities and thus lead to limited motion, increased wear, osteolysis, and subluxation or dislocation. Minimizing impingement involves avoiding skirted heads, matching a 22-mm head with an appropriate acetabular Implant, maximizing the head-to-neck ratio, and, when possible, using a chamfered acetabular liner and a trapezoidal, rather than circular, neck cross-section. Computer modeling studies indicate the optimal cup position is 45° to 55° abduction. Angles <55° require anteversion of 10° to 20° of both the stem and cup to minimize the risk of impingement and dislocation. J Am Acad Orthop Surg 2003;11:89-99
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Dislocation after total hip arthroplasty: Implant Design and orientation.
The Journal of the American Academy of Orthopaedic Surgeons, 2003Co-Authors: Robert L. BarrackAbstract:Implant Design and positioning are important factors in maintaining stability and minimizing dislocation after total hip arthroplasty. Although the advent of modular femoral stems and acetabular Implants increased the number of head, neck, and liner Designs, the features of recent Designs can cause intra-articular prosthetic impingement within the arc of motion required for normal daily activities and thus lead to limited motion, increased wear, osteolysis, and subluxation or dislocation. Minimizing impingement involves avoiding skirted heads, matching a 22-mm head with an appropriate acetabular Implant, maximizing the head-to-neck ratio, and, when possible, using a chamfered acetabular liner and a trapezoidal, rather than circular, neck cross-section. Computer modeling studies indicate the optimal cup position is 45° to 55° abduction. Angles
S. David Stulberg - One of the best experts on this subject based on the ideXlab platform.
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Does Implant Design Influence the Accuracy of Patient Specific Instrumentation in Total Knee Arthroplasty
The Journal of arthroplasty, 2015Co-Authors: Nitin Goyal, Anay Patel, Mark Yaffe, Michael Y. Luo, S. David StulbergAbstract:PSI software adjusts preoperative planning to accommodate differences in Implant Design. Such adjustments may influence the accuracy of intraoperative jig placement, bone resection, or component placement. Our purpose was to determine whether Implant Design influences PSI accuracy. 96 and 123 PSI TKA were performed by a single surgeon using two different Implant systems and identical PSI software. Femoral coronal alignment outliers were greater for Implant 1 (23.9% Implant 1 vs. 13.4% Implant 2; P=0.050). Tibial coronal alignment outliers were greater for Implant 2 (10.9% Implant 1 vs. 22.7% Implant 2; P=0.025). There was no difference in overall mechanical axes. Differences in Implant Design can influence bone resection and component alignment. PSI software rationale must align with surgeons' intraoperative goals.
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Does Implant Design Influence the Accuracy of Patient Specific Instrumentation in TKA
Journal of Bone and Joint Surgery-british Volume, 2013Co-Authors: Nitin Goyal, Anay Patel, Mark Yaffe, Micheal Luo, S. David StulbergAbstract:Introduction: Patient specific instrumentation (PSI) generates customized guides from a magnetic resonance imaging based preoperative plan for use in total knee arthroplasty (TKA). PSI software must be able to accommodate differences in Implant Design. The purpose of the present study was to determine whether any differences in the accuracy of limb alignment, component alignment, component sizing, or bony resection could be identified in patients undergoing PSI TKA with identical PSI software and one of two different Implant systems. Methods: In this case-control study, two different Implant systems from the same manufacturer were evaluated in 37 consecutive PSI TKA (Group 1) and 123 consecutive PSI TKA (Group 2) performed by a single surgeon. A third group (Group 3) consisted of 12 consecutive TKA performed with manual instrumentation and the same Implant system as Group 1. Identical software was used to generate a preoperative plan from which planned limb alignment, component alignment, component sizes, and bony resection were determined. Intraoperatively, actual component sizes, bony resection, and recut frequency were determined. Long-standing and lateral radiographs were obtained preoperatively and 4-weeks postoperatively to evaluate limb and component alignment. Results: Groups were similar with regard to age, gender, BMI, and preoperative alignment. No differences in the accuracy of limb alignment, component alignment, component sizing, or PSI-planned versus actual resection were found between Groups 1 and 2. The rate of recuts required was lower in Group 1 than Group 2 for the proximal tibia (3% vs. 35%; p Discussion: No discernible differences in the accuracy of limb alignment, component alignment, and component sizing were found between Groups 1 and 2. Group 1 required fewer recuts than Group 2 for the proximal tibia. There may be characteristics of Implant Design, e.g. the slope of the tibial plateau, that may influence the ability of PSI to accurately determine cut thickness. No differences in limb alignment, component alignment, or bony resection were identified between Groups 1 and 3. Group 1 showed less variability in resection depth than Group 3 in the posterior femur and proximal tibia. This study suggests that PSI can be equally accurate for different Implant systems. For a given Implant system, PSI shows less variation in resection depth when compared to manual instrumentation.
M Mansat - One of the best experts on this subject based on the ideXlab platform.
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INFLUENCE OF GLENOID Implant Design ON SCAPULAR BONE BEHAVIOUR: ANALYSIS BY FINITE ELEMENT MODELLISATION
2018Co-Authors: Pierre Mansat, D Lacroix, P Swider, M MansatAbstract:Purpose: Finite element analysis can be used to assess the behaviour of loaded structures. We used this method to evaluate the influence of glenoid Implant Design on the behaviour of an osteoarthritic scapula.Material and methods: A 76-year-old female patient scheduled for a shoulder prosthesis underwent preoperative computed tomography of the osteoarthritic shoulder. Two polyethylene Implants were evaluated: one with a triangular stem and the same prosthesis with three studs. 3D reconstruction of the glenoid cavity with the Implants was then obtained and processed with the finite elements method. Three loadings were applied to the model: centred loading to reproduce the case of an ideally stable prosthesis with a normal tendinomuscular environment and excentred loading to simulate a deficient rotator cuff or prosthesis instability.Results: With centred loading, stress remained low, to the order of 7 MPa, at the stem-glenoid cavity interface. Excentered loading produced peak stress on the borders of the g...
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INFLUENCE OF GLENOID Implant Design ON SCAPULAR BONE BEHAVIOUR: ANALYSIS BY FINITE ELEMENT MODELLISATION
Journal of Bone and Joint Surgery-british Volume, 2005Co-Authors: Pierre Mansat, D Lacroix, P Swider, M MansatAbstract:Purpose: Finite element analysis can be used to assess the behaviour of loaded structures. We used this method to evaluate the influence of glenoid Implant Design on the behaviour of an osteoarthritic scapula. Material and methods: A 76-year-old female patient scheduled for a shoulder prosthesis underwent preoperative computed tomography of the osteoarthritic shoulder. Two polyethylene Implants were evaluated: one with a triangular stem and the same prosthesis with three studs. 3D reconstruction of the glenoid cavity with the Implants was then obtained and processed with the finite elements method. Three loadings were applied to the model: centred loading to reproduce the case of an ideally stable prosthesis with a normal tendinomuscular environment and excentred loading to simulate a deficient rotator cuff or prosthesis instability. Results: With centred loading, stress remained low, to the order of 7 MPa, at the stem-glenoid cavity interface. Excentered loading produced peak stress on the borders of the glenoid Implants, directly under the loading zone and at the tip of the stem, at the bone-cement interface, reaching 20 MPa. The Implant tended to bend in the anteroposterior direction producing strong shear forces on the posterior part of the glenoid cavity. These forces caused micromovement at the cement-bone interface. There was no significant difference between the stem and stud Implants. Discussion: Eccentric loading of the glenoid Implant appears to have a negative effect on long-term survival, the stress reaching levels greater than the values of cement fatigue fracture. Peak stress was situated on the posterior border of the cement layer due to the small space available between the Implant the cortical bone in the posterior part of the osteoarthritic scapula. In this situation, the tip of the stem or the studs tend to come into contact with the posterior cortical of the scapula. When inserting a total shoulder prosthesis, it appears to be more important to keep in mind the geometry and the mechanical properties of the scapula than the Implant Design.
Eric Rompen - One of the best experts on this subject based on the ideXlab platform.
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Comparison of variable-thread tapered Implant Designs to a standard tapered Implant Design after immediate loading. A 3-year multicentre randomised controlled trial.
European journal of oral implantology, 2012Co-Authors: Christoph Arnhart, Andrej M. Kielbassa, Rafael Martínez De Fuentes, Moshe Goldstein, Jochen Jackowski, Martin Lorenzoni, Carlo Maiorana, Regina Mericske-stern, Alessandro Pozzi, Eric RompenAbstract:This randomised, controlled multicentre trial aimed at comparing two versions of a variable-thread dental Implant Design to a standard tapered dental Implant Design in cases of immediate functional loading for 36 months after loading.
Nitin Goyal - One of the best experts on this subject based on the ideXlab platform.
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Does Implant Design Influence the Accuracy of Patient Specific Instrumentation in Total Knee Arthroplasty
The Journal of arthroplasty, 2015Co-Authors: Nitin Goyal, Anay Patel, Mark Yaffe, Michael Y. Luo, S. David StulbergAbstract:PSI software adjusts preoperative planning to accommodate differences in Implant Design. Such adjustments may influence the accuracy of intraoperative jig placement, bone resection, or component placement. Our purpose was to determine whether Implant Design influences PSI accuracy. 96 and 123 PSI TKA were performed by a single surgeon using two different Implant systems and identical PSI software. Femoral coronal alignment outliers were greater for Implant 1 (23.9% Implant 1 vs. 13.4% Implant 2; P=0.050). Tibial coronal alignment outliers were greater for Implant 2 (10.9% Implant 1 vs. 22.7% Implant 2; P=0.025). There was no difference in overall mechanical axes. Differences in Implant Design can influence bone resection and component alignment. PSI software rationale must align with surgeons' intraoperative goals.
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Does Implant Design Influence the Accuracy of Patient Specific Instrumentation in TKA
Journal of Bone and Joint Surgery-british Volume, 2013Co-Authors: Nitin Goyal, Anay Patel, Mark Yaffe, Micheal Luo, S. David StulbergAbstract:Introduction: Patient specific instrumentation (PSI) generates customized guides from a magnetic resonance imaging based preoperative plan for use in total knee arthroplasty (TKA). PSI software must be able to accommodate differences in Implant Design. The purpose of the present study was to determine whether any differences in the accuracy of limb alignment, component alignment, component sizing, or bony resection could be identified in patients undergoing PSI TKA with identical PSI software and one of two different Implant systems. Methods: In this case-control study, two different Implant systems from the same manufacturer were evaluated in 37 consecutive PSI TKA (Group 1) and 123 consecutive PSI TKA (Group 2) performed by a single surgeon. A third group (Group 3) consisted of 12 consecutive TKA performed with manual instrumentation and the same Implant system as Group 1. Identical software was used to generate a preoperative plan from which planned limb alignment, component alignment, component sizes, and bony resection were determined. Intraoperatively, actual component sizes, bony resection, and recut frequency were determined. Long-standing and lateral radiographs were obtained preoperatively and 4-weeks postoperatively to evaluate limb and component alignment. Results: Groups were similar with regard to age, gender, BMI, and preoperative alignment. No differences in the accuracy of limb alignment, component alignment, component sizing, or PSI-planned versus actual resection were found between Groups 1 and 2. The rate of recuts required was lower in Group 1 than Group 2 for the proximal tibia (3% vs. 35%; p Discussion: No discernible differences in the accuracy of limb alignment, component alignment, and component sizing were found between Groups 1 and 2. Group 1 required fewer recuts than Group 2 for the proximal tibia. There may be characteristics of Implant Design, e.g. the slope of the tibial plateau, that may influence the ability of PSI to accurately determine cut thickness. No differences in limb alignment, component alignment, or bony resection were identified between Groups 1 and 3. Group 1 showed less variability in resection depth than Group 3 in the posterior femur and proximal tibia. This study suggests that PSI can be equally accurate for different Implant systems. For a given Implant system, PSI shows less variation in resection depth when compared to manual instrumentation.
