scholarly journals Biomechanical Evaluation of a Mandibular Spanning Plate Technique Compared to Standard Plating Techniques to Treat Mandibular Symphyseal Fractures

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Matthew Richardson ◽  
Jonathan Hayes ◽  
J. Randall Jordan ◽  
Aaron Puckett ◽  
Matthew Fort
Keyword(s):  
Peak Load ◽  
Parallel Plates ◽  
Mandibular Angle ◽  
Reconstruction Plate ◽  
Tukey Test ◽  
Lag Screw ◽  
Plate Technique ◽  
Biomechanical Behavior ◽  
Significant Difference ◽  
Biomechanical Evaluation

Purpose. The purpose of this study is to compare the biomechanical behavior of the spanning reconstruction plate compared to standard plating techniques for mandibular symphyseal fractures.Materials and Methods. Twenty-five human mandible replicas were used. Five unaltered synthetic mandibles were used as controls. Four experimental groups of different reconstruction techniques with five in each group were tested. Each synthetic mandible was subjected to a splaying force applied to the mandibular angle by a mechanical testing unit until the construct failed. Peak load and stiffness were recorded. The peak load and stiffness were analyzed using ANOVA and the Tukey test at a confidence level of 95% (P<0.05).Results. The two parallel plates’ group showed statistically significant lower values for peak load and stiffness compared to all other groups. No statistically significant difference was found for peak load and stiffness between the control (C) group, lag screw (LS) group, and the spanning plate (SP1) group.Conclusions. The spanning reconstruction plate technique for fixation of mandibular symphyseal fractures showed similar mechanical behavior to the lag screw technique when subjected to splaying forces between the mandibular gonial angles and may be considered as an alternative technique when increased reconstructive strength is needed.

Improvement Of Curvilinear Diagrams Of Concrete Deformation

2019 ◽  
pp. 99-104
Keyword(s):  
Reinforced Concrete ◽  
Peak Load ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
Significant Difference ◽  
Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

scholarly journals Biomechanical Evaluation of Tarsometatarsal Fusion Comparing Crossing Lag Screws and Lag Screw With Locking Plate

2021 ◽  
pp. 107110072110335
Author(s):  
Sarah Ettinger ◽  
Lisa-Christin Hemmersbach ◽  
Michael Schwarze ◽  
Christina Stukenborg-Colsman ◽  
Daiwei Yao ◽  
...  
Keyword(s):  
Locking Plate ◽  
Screw Fixation ◽  
Operative Procedure ◽  
Fixation Technique ◽  
Lag Screw ◽  
Group 15 ◽  
Fresh Frozen ◽  
Biomechanical Evaluation ◽  
The Stability ◽  
End Stage

Background: Tarsometatarsal (TMT) arthrodesis is a common operative procedure for end-stage arthritis of the TMT joints. To date, there is no consensus on the best fixation technique for TMT arthrodesis and which joints should be included. Methods: Thirty fresh-frozen feet were divided into one group (15 feet) in which TMT joints I-III were fused with a lag screw and locking plate and a second group (15 feet) in which TMT joints I-III were fused with 2 crossing lag screws. The arthrodesis was performed stepwise with evaluation of mobility between the metatarsal and cuneiform bones after every application or removal of a lag screw or locking plate. Results: Isolated lag-screw arthrodesis of the TMT I-III joints led to significantly increased stability in every joint ( P < .05). Additional application of a locking plate caused further stability in every TMT joint ( P < .05). An additional crossed lag screw did not significantly increase rigidity of the TMT II and III joints ( P > .05). An IM screw did not influence the stability of the fused TMT joints. For TMT III arthrodesis, lag-screw and locking plate constructs were superior to crossed lag-screw fixation ( P < .05). TMT I fusion does not support stability after TMT II and III arthrodesis. Conclusion: Each fixation technique provided sufficient stabilization of the TMT joints. Use of a lag screw plus locking plate might be superior to crossed screw fixation. An additional TMT I and/or III arthrodesis did not increase stability of an isolated TMT II arthrodesis. Clinical Relevance: We report the first biomechanical evaluation of TMT I-III arthrodesis. Our results may help surgeons to choose among osteosynthesis techniques and which joints to include in performing arthrodesis of TMT I-III joints.

scholarly journals Metacarpal shaft fixation: a biomechanical comparison of dorsal plating, lag screws, and headless compression screws

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Felix G. E. Dyrna ◽  
Daniel M. Avery ◽  
Ryu Yoshida ◽  
David Lam ◽  
Simon Oeckenpöhler ◽  
...  
Keyword(s):  
Peak Load ◽  
Rigid Fixation ◽  
Advantages And Disadvantages ◽  
Shaft Fractures ◽  
Metacarpal Shaft ◽  
Significant Difference ◽  
Load To Failure ◽  
Headless Compression Screws ◽  
Diaphyseal Fractures ◽  
Dorsal Plating

Abstract Background Metacarpal shaft fractures are common and can be treated nonoperatively. Shortening, angulation, and rotational deformity are indications for surgical treatment. Various forms of treatment with advantages and disadvantages have been documented. The purpose of the study was to determine the stability of fracture fixation with intramedullary headless compression screws in two types of metacarpal shaft fractures and compare them to other common forms of rigid fixation: dorsal plating and lag screw fixation. It was hypothesized that headless compression screws would demonstrate a biomechanical stronger construct. Methods Five matched paired hands (age 60.9 ± 4.6 years), utilizing non-thumb metacarpals, were used for comparative fixation in two fracture types created by an osteotomy. In transverse diaphyseal fractures, fixation by headless compression screws (n = 7) and plating (n = 8) were compared. In long oblique diaphyseal fractures, headless compression screws (n = 8) were compared with plating (n = 8) and lag screws (n = 7). Testing was performed using an MTS frame producing an apex dorsal, three point bending force. Peak load to failure and stiffness were calculated from the load-displacement curve generated. Results For transverse fractures, headless compression screws had a significantly higher stiffness and peak load to failure, means 249.4 N/mm and 584.8 N, than plates, means 129.02 N/mm and 303.9 N (both p < 0.001). For long oblique fractures, stiffness and peak load to failure for headless compression screws were means 209 N/mm and 758.4 N, for plates 258.7 N/mm and 518.5 N, and for lag screws 172.18 N/mm and 234.11 N. There was significance in peak load to failure for headless compression screws vs plates (p = 0.023), headless compression screws vs lag screws (p < 0.001), and plates vs lag screws (p = 0.009). There was no significant difference in stiffness between groups. Conclusion Intramedullary fixation of diaphyseal metacarpal fractures with a headless compression screw provides excellent biomechanical stability. Coupled with lower risks for adverse effects, headless compression screws may be a preferable option for those requiring rapid return to sport or work. Level of evidence Basic Science Study, Biomechanics.

scholarly journals Total Organic Carbon Assessment in Soils Cultivated with Agave tequilana Weber in Jalisco, Mexico

2020 ◽  
Vol 13 (1) ◽  
pp. 208
Author(s):  
Celia De La Mora-Orozco ◽  
José G. Flores-Garnica ◽  
Lucia M. Vega-Ramírez ◽  
Irma J. González-Acuña ◽  
Juan Nápoles-Armenta ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Management Practices ◽  
Water Saturation ◽  
Management Strategies ◽  
Information Criterion ◽  
Agave Tequilana ◽  
Tukey Test ◽  
Significant Difference ◽  
Agriculture Management

The Agave tequilana Weber is an important commercial crop in the State of Jalisco, Mexico. However, the agave cultivation generates significant soil loss. For that reason, knowledge about the implementation of the agriculture management practices, such as manure application and the combination of inorganic fertilizers and manure, are relevant. The objective of this research was to determine the effect of agricultural management practices on the total organic carbon (TOC) in the soil in three study locations: Arandas, Tepatitlán, and Acatic in the Altos Sur region of Jalisco. A random sampling was carried out in each study location, 12 samples were obtained for each location at 0–30 cm deep, and a total of 36 samples were analyzed. The evaluated parameters were the potential hydrogen (pH), electrical conductivity (EC), bulk density (BD), soil-water saturation (SWS), total nitrogen (TN), and total organic carbon (TOC). Basic statistics and correlations between parameters were generated. In addition, to estimate TOC from a multivariate analysis, models were developed based on the lowest Akaike information criterion (AIC) and of the classification and regression trees (CART). ANOVA and Tukey test were determined. Results demonstrated a significant difference in the TOC percentages between the study locations. The Tukey test showed that there is no difference in TOC content between the Tepatitlán and Arandas sites, but there is a difference between these two sites and the Acatic. The latter resulted with the lowest values of TOC. Long-term studies are recommended to develop crop management strategies.

Biomechanical Evaluation of Plate Versus Lag Screw Only Fixation of Distal Fibula Fractures

2015 ◽  
Vol 54 (5) ◽  
pp. 896-899 ◽  
Author(s):  
Amirhossein Misaghi ◽  
Josh Doan ◽  
Tracey Bastrom ◽  
Andrew T. Pennock
Keyword(s):  
Plate Versus ◽  
Distal Fibula ◽  
Lag Screw ◽  
Biomechanical Evaluation

Study on the Divergent Characteristics of Soil Fungi and Actinomycetes at Dry Lake Wetland on Typical Steppe

2011 ◽  
Vol 356-360 ◽  
pp. 2678-2681 ◽  
Author(s):  
Ji Zhao ◽  
Yu Qin Shao ◽  
Zi Long Zhao ◽  
Zheng Min Li ◽  
Xiao Tong Wu ◽  
...  
Keyword(s):  
Soil Fungi ◽  
Wetland Soil ◽  
Typical Steppe ◽  
Plate Technique ◽  
Dominant Soil ◽  
Significant Difference ◽  
Dry Lake ◽  
Lake Center

In this study, the composition and distribution of dominant soil filamentous microbes , such as fungi and actinomycetes, at dry lake wetland soil on typical steppe were measured through Spread-Plate-Technique; the divergent characteristics of two microbial floras at lake wetland and typical steppe were analyzed; and several indicators of soil filamentous microbes, for example, diversity, richness, evenness, and dominance, were calculated. For fungi, there is significant difference between lake center (LC), typical steppe (TS) & lake bed (LB), lake side (LS) for diversity and richness; and there is significant difference between LC and TS& LB and LS for dominance. For actinomycetes, there is significant difference between LC & LS, and LB& TS for diversity; and there is significant difference between LC&TS for richness; and there is significant difference between LC&LS for evenness. At LC, the most dominant floras is Mucor, accounting for 100%. At LB, Mucor accounts for 26.25% and Penicillium accounts for 45%. At LS, the dominant floras are Mucor, accounting for 48%, and Penicillium, accounting for 34.48%. At TS, Penicillium has become the dominant flora to account for 92.23%. For actinomycetes, the most dominant floras at LC is Griseofuscus, accounting for 55.71%. At LS, the dominant floras are Griseofuscus accounting for18.75%, and balding group, accounting for 20%. At TS, the dominant flora are Griseofuscus, accounting for16.08%, and Flav us, accounting for 14.69%.The results have demonstrated a better understanding toward the development and succession mechanisms of wetland to provide the basis for protection and rational utilizations of dry lake wetland.

Integrated dual lag screws versus single lag screw cephalomedullary nail constructs: a meta-analysis and systematic review

2021 ◽  
pp. 112070002098506
Author(s):  
James R Onggo ◽  
Mithun Nambiar ◽  
Jason D Onggo ◽  
Anuruban Ambikaipalan ◽  
Parminder J Singh ◽  
...  
Keyword(s):  
Functional Outcomes ◽  
Meta Analysis ◽  
Femoral Fractures ◽  
Harris Hip Score ◽  
Complication Rates ◽  
Non Union ◽  
Lag Screw ◽  
Significant Difference ◽  
Lower Complication ◽  
Cephalomedullary Nails

Background/Aim: This study aims to determine the safety and efficacy of integrated dual lag screw (IDL) cephalomedullary nails (CMN) when compared with single lag screw (SL) constructs, in the internal fixation of intertrochanteric femoral fractures. Methods: The Smith & Nephew InterTan IDL was compared with SL CMN group consisting of the Stryker Gamma-3 (G3) and Synthes Proximal Femoral Nail Antirotation (PFNA) CMN. A multi-database search was performed according to PRISMA guidelines. Data from studies assessing the clinical and radiological outcomes, complications and perioperative parameters of InterTan versus G3 or PFNA CMN in patients with intertrochanteric femoral fractures were extracted and analysed. Results: 15 studies were included in this meta-analysis, consisting of 2643 patients. InterTan was associated with lower complication rates in terms of all-cause revisions (OR 0.34; 95% CI, 0.22–0.51; p < 0.001), cut-outs (OR 0.30; 95% CI, 0.17–0.51; p < 0.001), medial or lateral screw migration (OR 0.19; 95% CI, 0.06–0.65; p = 0.008) as well as persistent hip and thigh pain (OR 0.65; 95% CI, 0.47–0.90; p = 0.008). In terms of perioperative parameters, InterTan is associated with longer operative times (MD 5.57 minutes; 95% CI, 0.37–10.78 minutes, p = 0.04) and fluoroscopy times (MD 38.89 seconds, 95% CI, 15.88–61.91 seconds; p < 0.001). There was no statistically significant difference in terms of clinical Harris Hip Score and radiological outcomes, non-union, haematoma, femoral fractures, varus collapse, length of stay and mean intraoperative blood loss between the 2 groups. Conclusions: Integrated dual lag screw cephalomedullary nails are associated with fewer revisions and complications. However, there is insufficient data to suggest that either nail construct is associated with better functional outcomes.

Difference in Critical Reynolds Number Between Hagen-Poiseuille and Plane Poiseuille Flows

2001 ◽  
Author(s):  
Hidesada Kanda
Keyword(s):  
Experimental Data ◽  
Reynolds Number ◽  
Poiseuille Flow ◽  
Average Velocity ◽  
Critical Reynolds Number ◽  
Inlet Section ◽  
Parallel Plates ◽  
Plane Poiseuille Flow ◽  
Contraction Ratio ◽  
Significant Difference

Abstract For plane Poiseuille flow, results of previous investigations were studied, focusing on experimental data on the critical Reynolds number, the entrance length, and the transition length. Consequently, concerning the natural transition, it was confirmed from the experimental data that (i) the transition occurs in the entrance region, (ii) the critical Reynolds number increases as the contraction ratio in the inlet section increases, and (iii) the minimum critical Reynolds number is obtained when the contraction ratio is the smallest or one, and there is no-shaped entrance or straight parallel plates. Its value exists in the neighborhood of 1300, based on the channel height and the average velocity. Although, for Hagen-Poiseuille flow, the minimum critical Reynolds number is approximately 2000, based on the pipe diameter and the average velocity, there seems to be no significant difference in the transition from laminar to turbulent flow between Hagen-Poiseuille flow and plane Poiseuille flow.

scholarly journals A Prospective Study of Strut versus Miniplate for Fractures of Mandibular Angle

2013 ◽  
Vol 6 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Amy S. Xue ◽  
John C. Koshy ◽  
Erik M. Wolfswinkel ◽  
William M. Weathers ◽  
Kristina P. Marsack ◽  
...  
Keyword(s):  
Mandibular Angle ◽  
Patient Demographics ◽  
Mandibular Angle Fracture ◽  
Plate Group ◽  
Angle Fracture ◽  
Significant Difference ◽  
Comminuted Fractures ◽  
Angle Fractures ◽  
A Prospective Study ◽  
To Receive

This prospective randomized clinical trial compared the treatment outcomes of strut plate and Champy miniplate in fixation of mandibular angle fractures. Patients with mandibular angle fracture were consented and enrolled into this study. Exclusion criteria include patients with severely comminuted fractures. The patients were randomly assigned to receive the strut plate or Champy miniplate for angle fracture fixation. Patient demographics, fracture characteristics, operative and postoperative outcomes were collected prospectively. Statistical analysis was performed to evaluate the significance of the outcome. A total of 18 patients were included in this study and randomly assigned to receive either the strut plate or Champy miniplate. Out of which five patients were excluded postoperatively due to complex fracture resulting in postoperative maxillomandibular fixation. The final enrollment was 13 patients, N = 6 (strut) and N = 7 (Champy). There was no statistically significant difference in the pretreatment variables. Nine of these patients had other associated facial fractures, including parasymphyseal and subcondylar fractures. Most of the (11) patients had sufficient follow-up after surgery. Both groups exhibited successful clinical unions of the mandibular angle fractures. The complications associated with the mandibular angle were 20% in the strut plate group and 16.7% in the Champy group. One patient in the strut plate group had a parasymphyseal infection, requiring hardware removal. The strut plate demonstrated comparable surgical outcome as the Champy miniplate. It is a safe and effective alternative for management of mandibular angle fracture.

scholarly journals PENGARUH FASE BULAN TERHADAP WAKTU TEBAR PANCING DAN LAJU TANGKAP MADIDIHANG (Thunnus albacares Bonnaterre, 1788) PADA ARMADA RAWAI TUNA

2017 ◽  
Vol 22 (4) ◽  
pp. 207
Author(s):  
Irwan Jatmiko ◽  
Bram Setyadji ◽  
Arief Wujdi
Keyword(s):  
Full Moon ◽  
Yellowfin Tuna ◽  
Catch Rate ◽  
Lunar Phase ◽  
Anova Analysis ◽  
Tukey Test ◽  
Significant Difference ◽  
New Moon ◽  
One Way Anova ◽  
Tuna Longline

Madidihang/yellowfin tuna merupakan salah satu jenis ikan tuna ekonomis penting bagi industri perikanan di Indonesia dengan kontribusi hasil tangkapan yang terbanyak. Penelitian ini bertujuan untuk mengetahui pengaruh fase bulan terhadap waktu mulai tebar pancing dan laju tangkap madidihang pada armada rawai tuna. Pengumpulan data dilakukan oleh pemantau ilmiah pada armada rawai tuna yang sebagian besar berbasis di Pelabuhan Benoa, Bali mulai Agustus 2005 hingga Juni 2014. Daerah penangkapan ikan dari armada rawai tuna yang diambil datanya berada di lokasi (lintang dan bujur) 9°-16° LS hingga 109°-120° BT. Analisis anova satu arah dan tes Tukey dilakukan untuk mengetahui pengaruh fase bulan terhadap waktu mulai tebar pancing dan laju tangkap madidihang. Total sebanyak 60 trip dan 1.467 hari operasi penangkapan armada rawai tuna dilakukan dalam penelitian ini. Analisis statistik anova satu arah menunjukkan bahwa terdapat pengaruh yang nyata pada fase bulan terhadap waktu mulai tebar pancing (p<0,05). Selanjutnya, tes Tukey menunjukkan bahwa waktu mulai tebar pancing pada saat bulan purnama dimulai pada pukul 9:00 pagi hari. Waktu ini lebih lambat sekitar 2 jam dari pada waktu mulai tebar pancing pada ketiga fase bulan lainnya (perbani awal, perbani akhir dan bulan baru) yang dilakukan sekitar pukul 7:00 pagi hari. Analisis statistik anova satu arah juga menunjukkan terdapat perbedaan yang nyata antar fase bulan terhadap laju tangkap madidihang (p<0,05). Selanjutnya, tes Tukey menunjukkan bahwa laju tangkap pada saat bulan baru dan perbani awal sebesar 0,13 ekor/100 mata pancing atau lebih besar dibandingkan nilai laju tangkap pada saat purnama dan perbani akhir yang hanya sebesar 0,09 ekor/100 mata pancing. Yellowfin tuna is one of the most economically important species for fisheries industry in Indonesia. The objectives of this study are to investigate the effect of lunar phase to the set time start and catch rate of yellowfin tuna on tuna longline vessels. Data collected by scientific observer on tuna longline vessels mainly based in Benoa Port, Bali from August 2005 to June 2014. Fishing ground of sampled longline tuna located from 9°-16° S to 109°-120° E. One-way anova analysis and Tukey test conducted to examine the effect of lunar phase to the set time start and catch rate of yellowfin tuna. A total of 60 trips and 1,467 fishing days of longline tuna fishing vessels operation have been sampled for in this study. One-way anova analysis showed that there was a significant difference of lunar phase to the set time start (p<0.05). Furthermore, Tukey test showed that the starting time for setting during the full moon begins at 9:00 am. Its time was around 2 hours slower than the start of setting of the other three moon phase (first quarter, last quarter and new moon) which start around 7:00 am. One-way anova analysis also showed that there was a significant difference of lunar phase to catch rate of yellowfin tuna (p<0.05). Furthermore, Tukey test confirmed that hook rate on new moon and first quarter was 0.13/100 hooks or 0.4 bigger than hook rate on full moon and last quarter with only 0.09/100 hooks.

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