An Efficient and Accurate Prediction of the Stability of Percutaneous Fixation of Acetabular Fractures With Finite Element Simulation

2011 ◽  
Vol 133 (9) ◽  
Author(s):  
V. B. Shim ◽  
J. Böshme ◽  
P. Vaitl ◽  
C. Josten ◽  
I. A. Anderson
Keyword(s):  
Finite Element ◽  
Posterior Wall ◽  
Acetabular Fractures ◽  
Fe Model ◽  
Open Approach ◽  
Percutaneous Fixation ◽  
Biomechanical Stability ◽  
Posterior Wall Fracture ◽  
Interfragmentary Movement ◽  
The Stability

Posterior wall fracture is one of the most common fracture types of the acetabulum and a conventional approach is to perform open reduction and internal fixation with a plate and screws. Percutaneous screw fixations, on the other hand, have recently gained attention due to their benefits such as less exposure and minimization of blood loss. However their biomechanical stability, especially in terms interfragmentary movement, has not been investigated thoroughly. The aims of this study are twofold: (1) to measure the interfragmentary movements in the conventional open approach with plate fixations and the percutaneous screw fixations in the acetabular fractures and compare them; and (2) to develop and validate a fast and efficient way of predicting the interfragmentary movement in percutaneous fixation of posterior wall fractures of the acetabulum using a 3D finite element (FE) model of the pelvis. Our results indicate that in single fragment fractures of the posterior wall of the acetabulum, plate fixations give superior stability to screw fixations. However screw fixations also give reasonable stability as the average gap between fragment and the bone remained less than 1 mm when the maximum load was applied. Our finite element model predicted the stability of screw fixation with good accuracy. Moreover, when the screw positions were optimized, the stability predicted by our FE model was comparable to the stability obtained by plate fixations. Our study has shown that FE modeling can be useful in examining biomechanical stability of osteosynthesis and can potentially be used in surgical planning of osteosynthesis.

scholarly journals Are Suprapectineal Quadrilateral Surface Buttressing Plates Performances Superior to Traditional Fixation? A Finite Element Analysis

2021 ◽  
Vol 11 (2) ◽  
pp. 858
Author(s):  
Mara Terzini ◽  
Andrea Di Pietro ◽  
Alessandro Aprato ◽  
Stefano Artiaco ◽  
Alessandro Massè ◽  
...  
Keyword(s):  
Finite Element ◽  
Movement Analysis ◽  
High Energy ◽  
Clinical Analysis ◽  
Acetabular Fractures ◽  
Element Analysis ◽  
Bone Stress ◽  
Interfragmentary Movement ◽  
Element Approach ◽  
Transverse Fractures

Acetabular fractures have a high impact on patient’s quality of life, and because acetabular fractures are high energy injuries, they often co-occur with other pathologies such as damage to cartilage that could increase related morbidity; thus, it appears of primary importance developing reliable treatments for this disease. This work aims at the evaluation of the biomechanical performances of non-conservative treatments of acetabular fractures through a finite element approach. Two pelvic plates models (the standard suprapectineal plate—SPP, and a suprapectineal quadrilateral surface buttressing plate—SQBP) were analyzed when implanted on transverse or T-shaped fractures. The plates geometries were adapted to the specific hemipelvis, mimicking the bending action that the surgeon performs on the plate intraoperatively. Implemented models were tested in a single leg stance condition. The obtained results show that using the SQBP plate in transverse and T-shaped acetabular fractures generates lower bone stress if compared to the SPP plate. Interfragmentary movement analysis shows that the SQBP plate guarantees greater stability in transverse fractures. In conclusion, the SQBP plate seems worthy of further clinical analysis, having resulted as a promising option in the treatment of transverse and T-shaped acetabular fractures, able to reduce bone stress values and to get performances comparable, and in some cases superior, to traditional fixation.

Application of projection-based model reduction to finite-element plate models for two-dimensional traveling waves

2016 ◽  
Vol 28 (14) ◽  
pp. 1886-1904 ◽  
Author(s):  
Vijaya VN Sriram Malladi ◽  
Mohammad I Albakri ◽  
Serkan Gugercin ◽  
Pablo A Tarazaga
Keyword(s):  
Finite Element ◽  
Model Reduction ◽  
Traveling Waves ◽  
Large Scale ◽  
Fe Model ◽  
Plate Model ◽  
Reduction Techniques ◽  
State Frequency ◽  
Scale Down ◽  
The Stability

A finite element (FE) model simulates an unconstrained aluminum thin plate to which four macro-fiber composites are bonded. This plate model is experimentally validated for single and multiple inputs. While a single input excitation results in the frequency response functions and operational deflection shapes, two input excitations under prescribed conditions result in tailored traveling waves. The emphasis of this article is the application of projection-based model reduction techniques to scale-down the large-scale FE plate model. Four model reduction techniques are applied and their performances are studied. This article also discusses the stability issues associated with the rigid-body modes. Furthermore, the reduced-order models are utilized to simulate the steady-state frequency and time response of the plate. The results are in agreement with the experimental and the full-scale FE model results.

Finite element analysis of the stability of transverse acetabular fractures in standing and sitting positions by different fixation options

Injury ◽  
2015 ◽  
Vol 46 ◽  
pp. S29-S35 ◽  
Author(s):  
Ahmet Ozgur Yildirim ◽  
Kadir Bahadir Alemdaroglu ◽  
Halil Yalcin Yuksel ◽  
Özdamar Fuad Öken ◽  
Ahmet Ucaner
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Acetabular Fractures ◽  
Element Analysis ◽  
The Stability

scholarly journals Modified Kocher-Langenbeck Approach for the Treatment of Posterior Wall or Column Acetabular Fractures: The One-Incision Two-Window Method

2020 ◽  
Author(s):  
Tien-Yu Yang ◽  
Po-Yao Chuang ◽  
Tsan-Wen Huang ◽  
Kuo-Chin Huang
Keyword(s):  
Posterior Wall ◽  
Acetabular Fractures ◽  
Fracture Group ◽  
Satisfaction Rate ◽  
Posterior Wall Fracture ◽  
The Mean ◽  
Group 2 ◽  
The One ◽  
Group 1

Abstract Background: The Kocher-Langenbeck (K-L) approach is the standard method for the treatment of posterior wall or column acetabular fractures. This approach allows direct access to the posterior structures of the acetabulum, but is limited cranially and caudally by the neurovascular bundle. The present study was conducted to assess the quality of reduction and the incidence of complications in patients who underwent the modified “one-incision two-window” K-L approach.Methods : This is a Retrospective case series with recruited thirteen consecutive patients from 2015 to 2017 who sustained an acute, displaced posterior wall or column acetabular fracture. All patients were treated with modified “one-incision two-window” K-L approach.Results: The mean operation time, mean intraoperative blood loss, and mean incision wound length were estimated to be 103.8 min (60-120 min), 373.1 mL (100-700 mL), and 9.7 cm (8.0-13.0 cm), respectively. The radiographic quality of reduction was graded as anatomical reduction (maximum residual displacement [MRD] ≤ 2 mm) in all cases, according to Matta’s criteria. Concerning the incidence of complications, there were no iatrogenic neurovascular injury, no surgical site infections, and no osteonecrosis of the femoral head or heterotopic ossification in this cohort. One patient with transverse posterior wall fracture (group 1) experienced deep vein thrombosis in the lesion leg. Another two patients with solitary posterior wall fracture (group 2) developed posttraumatic osteoarthritis, with one diagnosed as Tonnis grade I lesion and the other as Tonnis grade III lesion. With respect to the clinical treatment outcome, the mean visual analogue scale (VAS), mean modified Harris Hip Score (mHHS) and subjective satisfaction rate were 1.7 (1.0-2.0), 90.6 (81-100), and 84.6% (80%-90%), respectively. Although there was no significant difference in the satisfaction rate (82.9% vs. 87.0%, P = 0.941) at 12 months after surgery, group 1 patients had more increased VAS score (2.0 vs. 1.2, P = 0.016) and more decreased mHHS (87.7 vs. 94.6, P = 0.014) than group 2 patients. Conclusions: Our pilot study confirmed that the “one-incision two-window” K-L approach is a simple, safe, reliable, and effective way to manage acute, displaced posterior wall or column acetabular fractures.Level of evidence: Therapeutic study, level IV.

Numerical investigation on the stability of human upper cervical spine (C1–C3)

2021 ◽  
pp. 1-13
Author(s):  
Waseem Ur Rahman ◽  
Wei Jiang ◽  
Guohua Wang ◽  
Zhijun Li
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Axial Rotation ◽  
Upper Cervical Spine ◽  
Fe Model ◽  
Facet Joints ◽  
Flexion Extension ◽  
Upper Cervical ◽  
The Stability

BACKGROUND: The finite element method (FEM) is an efficient and powerful tool for studying human spine biomechanics. OBJECTIVE: In this study, a detailed asymmetric three-dimensional (3D) finite element (FE) model of the upper cervical spine was developed from the computed tomography (CT) scan data to analyze the effect of ligaments and facet joints on the stability of the upper cervical spine. METHODS: A 3D FE model was validated against data obtained from previously published works, which were performed in vitro and FE analysis of vertebrae under three types of loads, i.e. flexion/extension, axial rotation, and lateral bending. RESULTS: The results show that the range of motion of segment C1–C2 is more flexible than that of segment C2–C3. Moreover, the results from the FE model were used to compute stresses on the ligaments and facet joints of the upper cervical spine during physiological moments. CONCLUSION: The anterior longitudinal ligaments (ALL) and interspinous ligaments (ISL) are found to be the most active ligaments, and the maximum stress distribution is appear on the vertebra C3 superior facet surface under both extension and flexion moments.

Study on the Temperature Field of Cemented Carbide Substrate in Miniature EACVD System

2008 ◽  
Vol 375-376 ◽  
pp. 525-529
Author(s):  
Hong Xiang Wang ◽  
Dun Wen Zuo ◽  
Wen Zhuang Lu ◽  
Feng Xu ◽  
Dang Zeng ◽  
...  
Keyword(s):  
Growth Rate ◽  
Finite Element ◽  
Temperature Field ◽  
Substrate Temperature ◽  
Diamond Films ◽  
Element Model ◽  
Cemented Carbide ◽  
Fe Model ◽  
3D Finite Element ◽  
The Stability

The uniform distribution and the stability of the substrate temperature are the most important factors that deeply affect the quality and the growth rate of diamond films. In this paper, cemented carbide cutters were chosen for substrates, the 3D finite element (FE) model of filaments and substrates was developed in ANSYS 8.0, the calculated results show that the substrate temperature is influenced by the filament temperature, filaments diameter, the quantity of the filaments and the distance between the filaments and the substrates. The 3D finite element model of filaments and substrates also provides a basis for selecting the parameters to obtain uniform diamond films in miniature EACVD system.

A finite element based simulation framework for robotic grasp analysis

2020 ◽  
pp. 095440622095159
Author(s):  
SJ Dharbaneshwer ◽  
Asokan Thondiyath ◽  
Sankara J Subramanian ◽  
I-Ming Chen
Keyword(s):  
Finite Element ◽  
Contact Area ◽  
Hertzian Contact ◽  
Fe Model ◽  
Equilibrium Equations ◽  
Dynamic Conditions ◽  
Static Mechanical ◽  
Physical Attributes ◽  
The Stability ◽  
Hertzian Contact Theory

The commonly used grasp simulators such as GraspIt! and OpenRAVE use wrench space formulations and grasp quality metrics such as ϵ and v to identify stable grasps in dynamic conditions. However, wrench space formulations are derived based on static mechanical equilibrium equations, and the physical attributes of the object such as stiffness and mass are also not considered for grasp analysis. Above all, these grasp analysis frameworks cannot be experimentally validated, thereby resulting in grasps that are not reliable. In this paper, an experimentally validatable Finite Element (FE) based grasp analysis framework is proposed for evaluation of robotic grasps in dynamic conditions. By applying standard solutions of Hertzian contact theory to a few robotic grasps, Finite Element Method (FEM) is validated. A real-world grasp situation is then simulated using FEM, and the FE model is validated based on the contact area measured in real-time using a pressure sensor. By applying dynamic perturbations to the validated FE model, the stability of the grasp is evaluated, and the most stable grasp is identified using the contact area based metric, π. It is observed that FE simulations agree with the analytical solutions and experimental results, with a relative error of not more than 7%.

scholarly journals A study on fracture lines of the quadrilateral plate based on fracture mapping

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Yun Yang ◽  
Chang Zou ◽  
Yue Fang
Keyword(s):  
Posterior Wall ◽  
Anterior Column ◽  
Acetabular Fractures ◽  
Orthopedic Surgeons ◽  
Posterior Wall Fracture ◽  
Quadrilateral Plate ◽  
Fixation Devices ◽  
Different Types ◽  
Ct Data ◽  
Fracture Mapping

Abstract Background Quadrilateral plate fractures are a challenging group of acetabular fractures to manage. However, there is little literature that describes the fracture lines of the quadrilateral plate. The aim of this study was to explore the fracture lines of the quadrilateral plate and relevant clinical significance. Methods CT data from a series of acetabular fractures were retrospectively analyzed. According to the X-ray, CT, and operative records of the patients, Judet-Letournel classification was carried out for acetabular fractures involving quadrilateral plate. Then, the fracture maps of different types of acetabular fractures in the quadrilateral plate were drawn. To facilitate the characterization of fracture maps, we defined six basic fracture lines. Results The fracture lines of the three types of acetabular fractures (double-column fracture, T-type fracture, and anterior column with posterior hemitransverse fracture) mainly included upper transverse lines and upper oblique lines. Although the fracture lines of posterior wall fracture and anterior column fracture were mainly upper transverse lines, the fracture lines of the former were in a low position. The fracture lines of transverse fracture and transverse with posterior wall fracture were similar, both of which were mainly upper oblique lines. The fracture lines of posterior column fractures mainly included posterior vertical lines. Conclusions The fracture lines of different types of acetabular fractures have certain regularity respectively. Observation of the fracture lines of the quadrilateral plate based on fracture mapping can help orthopedic surgeons to enhance the understanding of the Judet-Letournel classification, which may have some significant guidance on the choice of operation approach and the design of internal fixation devices.

scholarly journals Modified Kocher-Langenbeck approach for the treatment of posterior wall or column acetabular fractures: The one-incision two-window method

2020 ◽  
Author(s):  
Tien-Yu Yang ◽  
Kuo-Chin Huang
Keyword(s):  
Posterior Wall ◽  
Acetabular Fractures ◽  
Fracture Group ◽  
Satisfaction Rate ◽  
Posterior Wall Fracture ◽  
The Mean ◽  
Group 2 ◽  
The One ◽  
Group 1

Abstract Abstract The Kocher-Langenbeck (K-L) approach is the standard method for the treatment of posterior wall or column acetabular fractures. This approach allows direct access to the posterior structures of the acetabulum, but is limited cranially and caudally by the neurovascular bundle. The present study was conducted to assess the quality of reduction and the incidence of complications in patients who underwent the modified “one-incision two-window” K-L approach. Methods : This is a Retrospective case series with recruited thirteen consecutive patients from 2015 to 2017 who sustained an acute, displaced posterior wall or column acetabular fracture. All patients were treated with modified “one-incision two-window” K-L approach. Results: The mean operation time, mean intraoperative blood loss, and mean incision wound length were estimated to be 103.8 min (60-120 min), 373.1 mL (100-700 mL), and 9.7 cm (8.0-13.0 cm), respectively. The radiographic quality of reduction was graded as anatomical reduction (maximum residual displacement [MRD] ≤ 2 mm) in all cases, according to Matta’s criteria. Concerning the incidence of complications, there were no iatrogenic neurovascular injury, no surgical site infections, and no osteonecrosis of the femoral head or heterotopic ossification in this cohort. One patient with transverse posterior wall fracture (group 1) experienced deep vein thrombosis in the lesion leg. Another two patients with solitary posterior wall fracture (group 2) developed posttraumatic osteoarthritis, with one diagnosed as Tonnis grade I lesion and the other as Tonnis grade III lesion. With respect to the clinical treatment outcome, the mean visual analogue scale (VAS), mean modified Harris Hip Score (mHHS) and subjective satisfaction rate were 1.7 (1.0-2.0), 90.6 (81-100), and 84.6% (80%-90%), respectively. Although there was no significant difference in the satisfaction rate (82.9% vs. 87.0%, P = 0.941) at 12 months after surgery, group 1 patients had more increased VAS score (2.0 vs. 1.2, P = 0.016) and more decreased mHHS (87.7 vs. 94.6, P = 0.014) than group 2 patients. Conclusions: Our pilot study confirmed that the “one-incision two-window” K-L approach is a simple, safe, reliable, and effective way to manage acute, displaced posterior wall or column acetabular fractures.

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