scholarly journals NUMERICAL ANALYSIS OF SHORT AND LONG INSTRUMENTATION IN THE TREATMENT OF THORACOLUMBAR FRACTURES CONSIDERING THE LIGAMENTOUS PORTION

2019 ◽  
Vol 18 (2) ◽  
pp. 144-150
Author(s):  
André Rafael Hubner ◽  
Danilo Mourão Ribeiro ◽  
Eduardo Dassoler ◽  
Daniel Gasparin ◽  
Charles Leonardo Israel ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Thoracolumbar Spine ◽  
Three Dimensional ◽  
Maximum Tensile Stress ◽  
Thoracolumbar Fractures ◽  
Level Of Evidence ◽  
Safety Coefficient ◽  
Computed Tomography Images ◽  
Three Dimensional Models ◽  
Anterior Posterior

ABSTRACT Objective: This study aims to numerically evaluate the surgical treatment of thoracolumbar fractures, comparing the strengths between the long and short fixations using the pedicle of the fractured vertebra, taking into account the supraspinous, intertransverse, and anterior longitudinal ligaments. Methods: A numerical analysis of the techniques of long and short fixation of a thoracolumbar spine fracture was performed using computed tomography images that were converted into three-dimensional models and analyzed through the ANSYS program. The two types of treatments were analyzed considering the tensions generated in the immediate postoperative period, when the fracture has not yet been consolidated. The anterior, posterior, supraspinal and intertransverse longitudinal ligaments were added, in addition to considering different vertebral geometries. Results: Taking into account that the maximum tensile stress of the material used in the metal implant, in the case of titanium, was 960 MPa, the highest tension found in the analysis of the short instrumentation was 346.83 MPa, reaching only 36.13% of the load the material supports, being, therefore, within a safety limit. The analysis performed in the spine with long instrumentation showed the highest tension value of 229.22 MPa. Conclusions: Considering the values found and the resistance of the synthesis material used, the short and long fixation can be considered in the treatment of thoracolumbar fractures with similarity and a good safety coefficient. Level of Evidence III; Case-Control.

scholarly journals Evaluation of the Effect of the Sulcus Angle and Lateral to Medial Facet Ratio of the Patellar Groove on Patella Tracking in Aging Subjects with Stable Knee Joint

2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
Jianghui Qin ◽  
Dongyang Chen ◽  
Zhihong Xu ◽  
Dongquan Shi ◽  
Jin Dai ◽  
...  
Keyword(s):  
Lower Limb ◽  
Lateral Displacement ◽  
Three Dimensional ◽  
Trochlear Groove ◽  
Patellar Tilt ◽  
Sulcus Angle ◽  
Lateral Tilt ◽  
Computed Tomography Images ◽  
Three Dimensional Models ◽  
Patella Tracking

Purpose.To determine whether the sulcus angle and the lateral to medial facet ratio correlate with patella lateral displacement and tilt in patients without patella instability.Methods.Computed tomography images of the lower limb of 64 patients without known arthropathy were collected. Three-dimensional models of the lower limb with a unified coordinate system were rebuilt by using Mimics software. The sulcus angle, lateral to medial facet ratio, lateral trochlear inclination of the patellar groove, tibial tuberosity-trochlear groove (TT-TG) distance, bisect offset index, and lateral tilt of the patella were measured. Pearson’s correlation test was used to determine the relationship between the aforementioned parameters.Results.Data from 51 patients were analyzed. The sulcus angle was negatively correlated with lateral tilt inclination (p<0.001,r=0.8406) and positively correlated with the bisect offset index (p=0.003,r=0.634) and patellar tilt (p=0.03,r=0.551); the lateral to medial facet ratio was positively correlated with TT-TG distance (p=0.003,r=0.643) and bisect offset index (p=0.026,r=0.559).Conclusion.The sulcus angle and lateral to medial facet ratio of the patellar groove can influence patella tracking in patients with stable knee joints.

A navigation system for shoulder arthroscopic surgery

2007 ◽  
Vol 221 (7) ◽  
pp. 801-812 ◽  
Author(s):  
K Tyryshkin ◽  
P Mousavi ◽  
M Beek ◽  
R E Ellis ◽  
D R Pichora ◽  
...  
Keyword(s):  
Navigation System ◽  
Shoulder Arthroscopy ◽  
Dimensional Space ◽  
Arthroscopic Surgery ◽  
Three Dimensional ◽  
Surgical Instruments ◽  
Surface Model ◽  
Ultrasound Images ◽  
Computed Tomography Images ◽  
Three Dimensional Models

The general framework and experimental validation of a novel navigation system designed for shoulder arthroscopy are presented. The system was designed to improve the surgeon's perception of the three-dimensional space within the human shoulder. Prior to surgery, a surface model of the shoulder was created from computed tomography images. Intraoperatively optically tracked arthroscopic instruments were calibrated. The surface model was then registered to the patient using tracked freehand ultrasound images taken from predefined landmark regions on the scapula. Three-dimensional models of the surgical instruments were displayed, in real time, relative to the surface model in a user interface. Laboratory experiments revealed only small registration and calibration errors, with minimal time needed to complete the intraoperative tasks.

Particle Based Numerical Analysis of Green Water on FPSO Deck

2013 ◽  
Author(s):  
Cezar Augusto Bellezi ◽  
Liang-Yee Cheng ◽  
Kazuo Nishimoto
Keyword(s):  
Experimental Data ◽  
Numerical Analysis ◽  
Sea Water ◽  
Three Dimensional ◽  
High Amplitude ◽  
Green Water ◽  
Scale Models ◽  
Three Dimensional Models ◽  
Reduced Scale ◽  
Good Agreement

The green water phenomenon is boarding of sea water onto the deck due to high amplitude waves, which can cause several damages to the equipment on deck. In the present paper the green water phenomenon on three-dimensional models is analyzed using the Moving Particles Semi-Implicit Method (MPS), a fully lagrangian method for incompressible flow. This work is focused on the validation of the method comparing the numerical results with experimental results for green water on reduced scale models. The pressure on sensors over the deck of the models shows good agreement with experimental data.

scholarly journals Morphological Classification of Trochlear Dysplasia Based On Three-Dimensional Models

2021 ◽  
Author(s):  
Jiangfeng Lu ◽  
Yanru Wang ◽  
Gang Ji ◽  
Fei Wang
Keyword(s):  
Trochlear Dysplasia ◽  
Three Dimensional ◽  
Patellofemoral Instability ◽  
Conventional Radiography ◽  
3D Models ◽  
Lateral View ◽  
Lateral Condyle ◽  
Level Of Evidence ◽  
Three Dimensional Models ◽  
Crossing Point

Abstract Background: Trochlear dysplasia (TD) is a common risk factor for the development of patellofemoral instability (PI). Dejour’s classification shows low agreement between conventional radiography and axial magnetic resonance imaging. The present study aimed to evaluate and categorize the true lateral view of three-dimensional (3D) femoral models in patients with TD. Methods: Computed tomography (CT) scans of 96 hip-knee-ankle joints (49 PI patients: 34 female, 15 male; mean age 19.1±6.7 years, range 12–41 years) during 2017–2019 were collected and analyzed. A senior orthopedic surgeon classified the true lateral views of femoral 3D models and raw CT images. The crossing-point site and lateral condyle/facet morphology (lateral condyle bump or supratrochlear spur) were the main criteria. Results: TD cases were classified into four types and their frequencies recorded: type 1 (7.3%) = crossing-point site in the proximal trochlear area and no lateral condyle bump or supratrochlear spur; type 2 (19.8%) = crossing-point site in the proximal trochlear area and presence of a lateral condyle bump or supratrochlear spur; type 3 (13.5%) = crossing-point site in the distal trochlear area and no lateral condyle bump or supratrochlear spur; type 4 (59.4%) = crossing-point site in the distal trochlear area and presence of lateral condyle bump or supratrochlear spur.Conclusion: The presentation of TD varies greatly among PI patients and can be categorized into four types. This new classification, based on true lateral views of 3D femoral models, may provide relatively reliable guidance when using trochleoplasty to treat TD. Level of Evidence: II, development of diagnostic or monitoring criteria in consecutive patients.

Cholesteatoma in three dimensions: a teaching tool and an aid to improved pre-operative consent

2009 ◽  
Vol 124 (2) ◽  
pp. 126-131 ◽  
Author(s):  
D P Morris ◽  
R G Van Wijhe
Keyword(s):  
Temporal Bone ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Teaching Tool ◽  
Surgical Experience ◽  
Teaching Programme ◽  
Computed Tomography Images ◽  
Three Dimensional Models ◽  
Temporal Bones ◽  
User Friendly

AbstractBackground:Otological surgeons face two recurring challenges. Firstly, we must foster an appreciation of the complex, three-dimensional anatomy of the temporal bone in order to enable our trainees to operate safely and independently. Secondly, we must explain to our patients the necessity for surgery which carries the potential for serious complication.Methods:Amira® software was applied to pre-operative computed tomography images of temporal bones with cholesteatoma, to create three-dimensional computer images. Normal structures and cholesteatoma were displayed in a user-friendly, interactive format, allowing both trainee and patient to visualise disease and important structures within the temporal bone.Results:Three cases, and their three-dimensional computer models are presented. Zoom, rotation and transparency functions complemented the three-dimensional effect.Conclusion:These three-dimensional models provided a useful adjunct to cadaveric temporal bone dissection and surgical experience for our residents' teaching programme. Also, patients with cholesteatoma reported a better understanding of their pre-operative condition when the models were used during the consenting process.

scholarly journals Application of three-dimensional printing for pre-operative planning in hip preservation surgery

2019 ◽  
Vol 6 (2) ◽  
pp. 164-169 ◽  
Author(s):  
Lauren Bockhorn ◽  
Stephanie S Gardner ◽  
David Dong ◽  
Christof Karmonik ◽  
Saba Elias ◽  
...  
Keyword(s):  
Treatment Plan ◽  
Three Dimensional ◽  
Case Series ◽  
Level Of Evidence ◽  
Three Dimensional Printing ◽  
Morphological Abnormalities ◽  
Operative Planning ◽  
Dimensional Models ◽  
Three Dimensional Models ◽  
Dimensional Printing

Abstract Three-dimensional printing is a valuable modality with broad clinical applications. Hip preservation surgery outcomes are dependent on correction of morphological abnormalities that may be optimally visualized with three-dimensional models. To assess the efficacy of three-dimensional models for patient and trainee education and to determine its benefits during pre-operative planning in hip preservation surgery. Sixteen patients with hip pathology were selected. Computed tomography was utilized to generate three-dimensional models. Customized Likert-style questionnaires were given to 10 hip preservation surgeons, 11 orthopedic surgery residents and 10 patients. All residents strongly agreed or agreed that the three-dimensional hip models helped them to understand patients’ pathology. All but one patient agreed that the models assisted in their understanding of the treatment plan. Surgeons concurred that although they do not routinely order three-dimensional models, their use would improve trainee and patient education, especially when treating atypical osseous pathomorphologies. Three-dimensional models are tools that can help surgeon, trainee and patient understanding and participation in treatment of complex hip disorders. Patients and trainees agree that the prototypes enhanced their educational experience, as the surgeon can directly demonstrate complex morphological abnormalities. Trainees can therefore gain a better understanding of hip pathologies and treatment. As patients better understand their hip disorder, they can more fully participate in shared treatment decision-making. Level of Evidence Level IV, Retrospective Case Series

scholarly journals Digit Bones (Acropodium) of Gazella (Gazella subgutturosa); Three-Dimensional Modelling and Morphometry

2021 ◽  
Vol 41 (04) ◽  
pp. 481-486
Author(s):  
Ismail Demircioglu
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Male Adult ◽  
Three Dimensional Modeling ◽  
Surface Areas ◽  
Computed Tomography Images ◽  
Significant Difference ◽  
Three Dimensional Models ◽  
The Right ◽  
Gazella Subgutturosa

The present study was conducted to identify morphometric values and to reveal differences between sexes through three-dimensional modeling of digit bones (ossa phalanges) of gazella by using computed tomography images. A total of 14 (7 female, 7 male) adult gazella (Gazella subgutturosa) cadavers were used in the study. The images were extracted by scanning acropodium bones of gazella at 64-detector Multi Detector Computed Tomography (MDCT) in cross section thickness of 0.625mm. Using MIMICS 20.1 program, three-dimensional models of these images were prepared and morphometric measurements were taken. In GLpe and Bd measurements of Phalanx proximalis, a statistically significant difference was established between females and males in terms of the left forelimb internal, the right forelimb internal, the right forelimb external, and the right hindlimb external bones (P<0.05). There was a statistically significant difference between females and males in terms of volume of phalanx proximalis and surface area of the right forelimb internal phalanx proximalis (P<0.001). In GLpe measurements, a statistically significant difference was determined between females and males in terms of the left forelimb internal, the right forelimb internal, the right hindlimb internal, the left forelimb external, the right forelimb external, and the right hindlimb external phalanx media (P<0.05). A statistically significant difference was determined between females and males in terms of the data related to volume and surface areas of the left hindlimb internal the right hindlimb internal, the left hindlimb external, and the right hindlimb external phalanx distalis (P<0.05).

scholarly journals Mode I Interlaminar Fracture of Glass/Epoxy Unidirectional Laminates. Part II: Numerical Analysis

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1604 ◽  
Author(s):  
A. Gliszczynski ◽  
S. Samborski ◽  
N. Wiacek ◽  
J. Rzeczkowski
Keyword(s):  
Numerical Analysis ◽  
Three Dimensional ◽  
Interface Element ◽  
Mode I ◽  
Zone Method ◽  
Geometrically Nonlinear Analysis ◽  
Interlaminar Fracture ◽  
Dimensional Models ◽  
Three Dimensional Models ◽  
Delamination Front

The paper deals with numerical analysis of double cantilever beam (DCB) predefined to Mode I Interlaminar Fracture Tests of GRFP unidirectional laminates. The numerical analyses were performed in the ANSYS® program based on the finite element. In geometrically nonlinear analysis, two algorithms, responsible for initiation and propagation of delamination front, were applied: Virtual Crack Closure Technique (VCCT) and Cohesive zone method (CZM). Due to the unidirectional arrangement of layers of the laminate, the problem of DCB test was solved with the use of one- and three-dimensional models with the implementation of linear interface element and contact element. The present study highlights the limitations of existing formulae used to reliably reflect the behavior of DCB. The use of three-dimensional models allowed confirming the curved shape of the delamination front observed in experimental studies. The application of the VCCT in the three-dimensional model led to an underestimation of the global response (force–opening displacement curve) recorded during numerical DCB test.

scholarly journals Treatment of Fractures of the Thoracolumbar Spine: Recommendations of the Spine Section of the German Society for Orthopaedics and Trauma (DGOU)

2018 ◽  
Vol 8 (2_suppl) ◽  
pp. 34S-45S ◽  
Author(s):  
Akhil P. Verheyden ◽  
Ulrich J. Spiegl ◽  
Helmut Ekkerlein ◽  
Erol Gercek ◽  
Stefan Hauck ◽  
...  
Keyword(s):  
Literature Review ◽  
Systematic Literature Review ◽  
General Condition ◽  
Clinical Presentation ◽  
Thoracolumbar Spine ◽  
German Society ◽  
Level Of Evidence ◽  
Levels Of Care ◽  
Thoracolumbar Spine Fractures ◽  
Anterior Posterior

Study Design: Abstract consensus paper with systematic literature review. Objective: The aim of this study was to establish recommendations for treatment of thoracolumbar spine fractures based on systematic review of current literature and consensus of several spine surgery experts. Methods: The project was initiated in September 2008 and published in Germany in 2011. It was redone in 2017 based on systematic literature review, including new AOSpine classification. Members of the expert group were recruited from all over Germany working in hospitals of all levels of care. In total, the consensus process included 9 meetings and 20 hours of video conferences. Results: As regards existing studies with highest level of evidence, a clear recommendation regarding treatment (operative vs conservative) or regarding type of surgery (posterior vs anterior vs combined anterior-posterior) cannot be given. Treatment has to be indicated individually based on clinical presentation, general condition of the patient, and radiological parameters. The following specific parameters have to be regarded and are proposed as morphological modifiers in addition to AOSpine classification: sagittal and coronal alignment of spine, degree of vertebral body destruction, stenosis of spinal canal, and intervertebral disc lesion. Meanwhile, the recommendations are used as standard algorithm in many German spine clinics and trauma centers. Conclusion: Clinical presentation and general condition of the patient are basic requirements for decision making. Additionally, treatment recommendations offer the physician a standardized, reproducible, and in Germany commonly accepted algorithm based on AOSpine classification and 4 morphological modifiers.

Plastic replicas as three-dimensional models of pulps

1975 ◽  
Vol 39 (8) ◽  
pp. 544-546
Author(s):  
HL Wakkerman ◽  
GS The ◽  
AJ Spanauf
Keyword(s):  
Three Dimensional ◽  
Dimensional Models ◽  
Three Dimensional Models
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