Assessing the Local Mechanical Environment in Medial Opening Wedge High Tibial Osteotomy Using Finite Element Analysis

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Yves Pauchard ◽  
Todor G. Ivanov ◽  
David D. McErlain ◽  
Jaques S. Milner ◽  
J. Robert Giffin ◽  
...  
Keyword(s):  
Finite Element ◽  
High Tibial Osteotomy ◽  
Volume Fraction ◽  
Compressive Strain ◽  
Tibial Osteotomy ◽  
Fe Modeling ◽  
Knee Alignment ◽  
Mechanical Environment ◽  
Significant Difference ◽  
Subject Specific

High-tibial osteotomy (HTO) is a surgical technique aimed at shifting load away from one tibiofemoral compartment, in order the reduce pain and progression of osteoarthritis (OA). Various implants have been designed to stabilize the osteotomy and previous studies have been focused on determining primary stability (a global measure) that these designs provide. It has been shown that the local mechanical environment, characterized by bone strains and segment micromotion, is important in understanding healing and these data are not currently available. Finite element (FE) modeling was utilized to assess the local mechanical environment provided by three different fixation plate designs: short plate with spacer, long plate with spacer and long plate without spacer. Image-based FE models of the knee were constructed from healthy individuals (N = 5) with normal knee alignment. An HTO gap was virtually added without changing the knee alignment and HTO implants were inserted. Subsequently, the local mechanical environment, defined by bone compressive strain and wedge micromotion, was assessed. Furthermore, implant stresses were calculated. Values were computed under vertical compression in zero-degree knee extension with loads set at 1 and 2 times the subject-specific body weight (1 BW, 2 BW). All studied HTO implant designs provide an environment for successful healing at 1 BW and 2 BW loading. Implant von Mises stresses (99th percentile) were below 60 MPa in all experiments, below the material yield strength and significantly lower in long spacer plates. Volume fraction of high compressive strain ( > 3000 microstrain) was below 5% in all experiments and no significant difference between implants was detected. Maximum vertical micromotion between bone segments was below 200 μm in all experiments and significantly larger in the implant without a tooth. Differences between plate designs generally became apparent only at 2 BW loading. Results suggest that with compressive loading of 2 BW, long spacer plates experience the lowest implant stresses, and spacer plates (long or short) result in smaller wedge micromotion, potentially beneficial for healing. Values are sensitive to subject bone geometry, highlighting the need for subject-specific modeling. This study demonstrates the benefits of using image-based FE modeling and bone theory to fine-tune HTO implant design.

Development of a Finite Element Model of the Inferior Glenohumeral Ligament of the Glenohumeral Joint

2003 ◽  
Author(s):  
William J. Newman ◽  
Richard E. Debski ◽  
Susan M. Moore ◽  
Jeffrey A. Weiss
Keyword(s):  
Finite Element ◽  
Glenohumeral Joint ◽  
External Rotation ◽  
Element Model ◽  
Fe Modeling ◽  
Glenohumeral Ligament ◽  
Subject Specific ◽  
Inferior Glenohumeral Ligament ◽  
Glenohumeral Capsule ◽  
Shoulder Stability

The shoulder is one of the most complex and often injured joints in the human body. The inferior glenohumeral ligament (IGHL), composed of the anterior band (AB), posterior band (PB) and the axillary pouch, has been shown to be an important contributor to anterior shoulder stability (Turkel, 1981). Injuries to the IGHL of the glenohumeral capsule are especially difficult to diagnose and treat effectively. The objective of this research was to develop a methodology for subject-specific finite element (FE) modeling of the ligamentous structures of the glenohumeral joint, specifically the IGHL, and to determine how changes in material properties affect predicted strains in the IGHL at 60° of external rotation. Using the techniques developed in this research, an improved understanding of the contribution of the IGHL to shoulder stability can be acquired.

scholarly journals Arthroscopy-Assisted Computer Navigation in High Tibial Osteotomy for Varus Knee Deformity

2009 ◽  
Vol 17 (1) ◽  
pp. 51-55 ◽  
Author(s):  
WN Lo ◽  
KW Cheung ◽  
SH Yung ◽  
KH Chiu
Keyword(s):  
High Tibial Osteotomy ◽  
Computer Navigation ◽  
Mean Deviation ◽  
Tibial Osteotomy ◽  
Open Wedge ◽  
Varus Knee ◽  
Knee Alignment ◽  
Knee Deformity ◽  
The Mean ◽  
Open Wedge Hto

Purpose. To assess the accuracy of knee alignment after high tibial osteotomy (HTO) for varus knee deformity using arthroscopy-assisted computer navigation. Methods. Six men and 4 women aged 47 to 53 (mean, 49) years underwent medial open wedge HTO for varus knee deformity and medial unicompartmental osteoarthritis using arthroscopy-assisted computer navigation with fluoroscopy. Patients were followed up for a mean of 23 (range, 11–32) months. Intra- and post-operative leg alignments were compared. Results. The mean postoperative coronal plane alignment was 2.7 (range, 1–4) degree valgus; the mean deviation from intra-operative computer images was one (range, 0.1–1.9) degree; 5 knees had less valgus in the postoperative radiographs than the intra-operative computer images. Conclusion. Despite being more technically demanding, time consuming, and costly, arthroscopy-assisted computer navigation is safe, accurate, and reliable for HTO.

Electrothermomechanical Modeling and Analyses of Carbon Nanotube Polymer Composites

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
S. Xu ◽  
O. Rezvanian ◽  
M. A. Zikry
Keyword(s):  
Finite Element ◽  
Carbon Nanotube ◽  
Polymer Composites ◽  
Volume Fraction ◽  
Electron Tunneling ◽  
Three Dimensional ◽  
Fe Modeling ◽  
Aspect Ratios ◽  
Reinforced Polymer ◽  
Polymer Dispersions

A new finite element (FE) modeling method has been developed to investigate how the electrical-mechanical-thermal behavior of carbon nanotube (CNT)–reinforced polymer composites is affected by electron tunneling distances, volume fraction, and physically realistic tube aspect ratios. A representative CNT polymer composite conductive path was chosen from a percolation analysis to establish the three-dimensional (3D) computational finite-element (FE) approach. A specialized Maxwell FE formulation with a Fermi-based tunneling resistance was then used to obtain current density evolution for different CNT/polymer dispersions and tunneling distances. Analyses based on thermoelectrical and electrothermomechanical FE approaches were used to understand how CNT-epoxy composites behave under electrothermomechanical loading conditions.

scholarly journals Biomechanical evaluation of high tibial osteotomy plate with internal support block using finite element analysis

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247412
Author(s):  
Jesse Chieh-Szu Yang ◽  
Kuan-Yu Lin ◽  
Hsi-Hsien Lin ◽  
Oscar K. Lee
Keyword(s):  
Finite Element ◽  
High Tibial Osteotomy ◽  
Tibial Plateau ◽  
Bone Plate ◽  
Osteotomy Site ◽  
Tibial Osteotomy ◽  
Sit To Stand ◽  
Internal Support ◽  
Locking Screw ◽  
Tomofix Plate

Background/Objective High tibial osteotomy (HTO) is a common treatment for medial knee arthrosis. However, a high rate of complications associated with a plate and a significant loss of correction have been reported. Therefore, an internal support block (ISB) is designed to enhance the initial stability of the fixation device that is important for successful bone healing and maintenance of the correction angle of the osteotomy site. The purpose of this study was performed to examine if an internal support block combined with a plate reduces the stress on the plate and screw area. Methods Finite element models were reconstructed following three different implant combinations. Two loading conditions were applied to simulate standing and initial sit-to-stand postures. Data analysis was conducted to evaluate the axial displacement of the posteromedial tibial plateau, which represents the loss of the posteromedial tibial plateau in clinical observation. Moreover, the stresses on the bone plate and locking screws were evaluated. Results Compared to the TomoFix plate, the ISB reduced the axial displacement by 73% and 76% in standing and initial sit-to-stand loading conditions, respectively. The plate with an ISB reduced stress by 90% on the bone plate and by 73% on the locking screw during standing compared to the standalone TomoFix plate. During the initial sit-to-stand loading condition, the ISB reduced the stress by 93% and 77% on the bone plate and the locking screw, respectively. Conclusion The addition of the PEEK block showed a benefit for structural stability in the osteotomy site. However, further clinical trials are necessary to evaluate the clinical benefit of reduced implant stress and the internal support block on the healing of the medial bone tissue.

Short-term Outcomes after High Tibial Osteotomy Aimed at Neutral Alignment Combined with Arthroscopic Centralization of Medial Meniscus in Osteoarthritis Patients

2020 ◽  
Author(s):  
Hiroki Katagiri ◽  
Yusuke Nakagawa ◽  
Kazumasa Miyatake ◽  
Koji Otabe ◽  
Toshiyuki Ohara ◽  
...  
Keyword(s):  
Knee Osteoarthritis ◽  
High Tibial Osteotomy ◽  
Medial Meniscus ◽  
Control Group ◽  
Tibial Osteotomy ◽  
Short Term ◽  
Subjective Satisfaction ◽  
Significant Difference ◽  
Neutral Alignment

Abstract Purpose To improve long-term outcomes of open-wedge high tibial osteotomy (OWHTO), procedures combining OWHTO aimed at neutral alignment and arthroscopic centralization for meniscal extrusion have been introduced. The purpose of the present study was to compare short-term clinical and radiological outcomes of medial joint space width (JSW) after the OWHTO aimed at neutral alignment with and without arthroscopic centralization for an extruded medial meniscus. Methods A retrospective review of 50 primary OWHTO patients was conducted. Thirty-five patients included for analysis after exclusion criteria was applied. Twenty-one knee osteoarthritis patients, who underwent the OWHTO with arthroscopic meniscal centralization, were included in the centralization group. Fourteen patients, who underwent solely OWHTO, were included in the control group. Lysholm knee scale, International Knee Documentation Committee (IKDC) subjective score, Knee Osteoarthritis Outcome Score (KOOS), and patient subjective satisfaction scores were recorded at the final follow-up. Radiographic changes of JSW and joint line congruence angle (JLCA) were measured 2 years postoperatively. Patient demographic data were also reviewed. Results IKDC subjective scores, KOOS subgroup scores, patient subjective satisfaction scores, and Lysholm score did not show significant differences between the two groups at the final follow-up. Change of the JSW in the centralization group was significantly greater than that in the control group 2 years postoperatively (Control group: -0.1 mm, Centralization group: 0.8 mm P =0.03). Conclusion Change of JSW after OWHTO aimed at neutral alignment with arthroscopic centralization for extruded medial meniscus was greater than solely OWHTO, and there was no significant difference in the short-term clinical outcomes between the 2 procedures at the final follow-up.

Effects of plate contouring quality on the biomechanical performance of high tibial osteotomy fixation: A parametric finite element study

2022 ◽  
pp. 095441192110692
Author(s):  
Zahra Hayatbakhsh ◽  
Farzam Farahmand
Keyword(s):  
Finite Element ◽  
High Tibial Osteotomy ◽  
Plate Fixation ◽  
Element Model ◽  
Von Mises Stress ◽  
Osteotomy Site ◽  
Tibial Osteotomy ◽  
Intimate Contact ◽  
Initial Shape ◽  
Pull Out

Locking plates have threaded holes, in which threaded-head screws are affixed. Hence, they do not need to be in intimate contact with underlying bone to provide fixation. There are, however, reports that a large distance between the plate and the bone might cause clinical complications such as delayed union or nonunion, screw pull out, and screw and plate breakage. Considering the diversity in the capabilities and costs of different plate customization techniques, the purpose of this study was to investigate the effect of the plate contouring quality on the biomechanical performance of high tibial osteotomy (HTO) fixation. A finite element model of proximal tibia was developed in Abaqus, using the QCT data of a cadaver. The model was then subjected to open-wedge HTO (correction angle 12°) with TomoFix plate fixation. The sagittal curvature of the plate was changed parametrically to provide certain levels of geometrical fit, and the biomechanical performance parameters of fixation were assessed. Results indicated 5%, 9% and 38% increase in the stiffness of the construct, and the von Mises stress in the plate and locking screw just above the osteotomy site, respectively, when the level of fit of plate changed from 0% (initial non-contoured initial shape) to 100% (fully adapted shape). The same change decreased the pressure at the lateral hinge of the osteotomy by 61%, and the mean of the tensile stress on the screw shaft by 12%. It was concluded that the level of fit has conflicting effects on the biomechanical parameters of the HTO fixation system, that is, the structural stiffness, the pressure at the lateral hinge, the stresses in the plate and screws, and the pull out resistance of the screws. In particular, for HTO patients with high quality bone, the optimal level of fit should provide a tradeoff between these parameters.

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