Method for testing bending strength and stiffness of bone plates for use in orthopaedic surgery

1983 ◽  
Keyword(s):  
Orthopaedic Surgery ◽  
Bending Strength ◽  
Bone Plates ◽  
Strength And Stiffness

Mechanical testing of 3.5 mm locking and non-locking bone plates

2008 ◽  
Vol 21 (04) ◽  
pp. 318-322 ◽  
Author(s):  
M. DeTora ◽  
K. Kraus
Keyword(s):  
Mechanical Testing ◽  
Locking Plate ◽  
Bending Strength ◽  
Dynamic Compression ◽  
Test Method ◽  
Bone Plates ◽  
Orthopaedic Implant ◽  
Orthopaedic Implants ◽  
Strength And Stiffness

SummaryLocking plate technologies are being developed in order to provide the surgeon with advantages over previous bone plate systems (both locking and non-locking). Locking plate systems possess inherent biological advantages in fracture fixation by preserving the periosteal blood supply, serving as internal fixators. It is important to consider the strength of each orthopaedic implant as an important selection criterion while utilizing the reported advantages of locking plate systems to prevent catastrophic fracture failure. Mechanical testing of orthopaedic implants is a common method used to provide a surgeon with insight on mechanical capabilities, as well as to form a standardized method of plate comparison. The purpose of this study was to demonstrate and to quantify observed differences in the bending strength between the LCP (Limited Contact Plate), LC-DCP, 3.5 mm Broad LC-DCP (Limited Contact Dynamic Compression Plate), and SOP (String of Pearls) orthopaedic bone plates. The study design followed the ASTM standard test method for static bending properties of metallic bone plates, which is designed to measure mechanical properties of bone plates subjected to bending, the most common loading encountered in vivo. Single cycle four point bending was performed on each orthopaedic implant. The area moment of inertia, bending stiffness, bending strength, and bending structural stiffness were calculated for each implant. The results of this study demonstrated significant differences (p<0.001) in bending strength and stiffness between the four orthopaedic implants (3.5 Broad LC-DCP>SOP>LCP=LC-DCP). The 3.5 mm LCP should be expected to provide in vivo strength and stiffness similar to a comparable LC-DCP. The SOP should provide strength and stiffness that is greater than a comparable LC-DCP but less than a 3.5 mm Broad LC-DCP.

scholarly journals Effectiveness and Subjectivity of Visual Inspection as a Method to Assess Bending Stiffness and Strength of Chestnut Elements

2013 ◽  
Vol 778 ◽  
pp. 175-182 ◽  
Author(s):  
Hélder S. Sousa ◽  
Jorge M. Branco ◽  
Paulo B. Lourenço
Keyword(s):  
Visual Inspection ◽  
Bending Strength ◽  
Castanea Sativa ◽  
Bayesian Probability ◽  
Maximum Diameter ◽  
Visual Grading ◽  
Bending Tests ◽  
Coefficients Of Variation ◽  
Strength And Stiffness

Besides the difficulty of assessing an existing timber structure on site, the efficiency and accuracy of visual inspection is often compromised by its subjective nature inherited by the level of expertise of the inspector. This often leads to conservative predictions of the mechanical properties, even with the use of specific visual grading norms. The main objectives of this work are to assess the effectiveness of visual inspection as a method to define different classes of strength and stiffness and to provide a statistical analysis on its subjectivity. For that aim, visual inspection using Italian standard UNI 11119:2004 and bending tests of 20 old chestnut beams (Castanea sativa Mill.) at different scale element, were carried out. Comparisons and effectiveness of visual inspection is analyzed within and between different scales of the timber members, and also regarding different level of expertise of inspectors. The results evidence similar percentages of segments classified with higher and lower visual inspections classes and proved to be a good qualitative indicator of bending strength between sawn beams. An overall 42% accuracy of the most experienced inspectors was found with better differentiation between visual classes, whereas lower level inspectors scored approximately less 5%. Lower level inspectors also evidenced higher concentration of values around a higher mean for each class denoting a more conservative approach. Regardless of the inspector level, knot size was considered the main limiting visual parameter with higher influence in small scales of the timber elements. When studying the characterization of a single knot, coefficients of variation of 15.7% and 21.8% were found for measuring the minimum and maximum diameter. Bayesian probability networks were considered as to individually assess the accuracy in stiffness prediction of different level of inspectors, and by combination of their information, evidencing that parallel combination for prior information may allow the increase in visual inspection accuracy.

In vitro biomechanical evaluation and comparison of a new prototype locking plate and a limited-contact self compression plate for equine fracture repair

2012 ◽  
Vol 25 (04) ◽  
pp. 273-280
Author(s):  
D. D. Quinteros ◽  
G. A. Abuja ◽  
M. Tarkanian ◽  
L. S. Maranda ◽  
K. Bubeck ◽  
...  
Keyword(s):  
Locking Plate ◽  
Bending Strength ◽  
Fatigue Testing ◽  
Cyclic Fatigue ◽  
Fracture Repair ◽  
Single Cycle ◽  
Four Point Bending ◽  
Metacarpal Bones ◽  
Compression Plate ◽  
Strength And Stiffness

SummaryObjective: To determine if the mechanical properties (strength and stiffness) of a new prototype 4.5 mm broad locking plate (NP-LP) are comparable with those of a traditional 4.5 mm broad limited-contact self compression plate (LC-SCP), and to compare the bending and torsional properties of the NP-LP and LCSCP when used in osteotomized equine third metacarpal bones (MC3).Methods: The plates alone were tested in four-point bending single cycle to failure. The MC3-plate constructs were created with middiaphyseal osteotomies with a 1 cm gap. Constructs were tested in four-point bending single cycle to failure, four-point bending cyclic fatigue, and torsion single cycle to failure.Results: There were not any significant differences in bending strength and stiffness found between the two implants. The MC3-NP-LP construct was significantly stiffer than the MC3-LC-SCP in bending. No other biomechanical differences were found in bending, yield load in torsion, or mean composite rigidity. Mean cycles to failure for bending fatigue testing were similar for both constructs.Clinical significance: The NP-LP was comparable to the LC-SCP in intrinsic, as well as structural properties. The NP-LP construct was more rigid than the LC-SCP construct under four-point bending, and both constructs behaved similarly under four-point bending cyclic fatigue testing and torsion single cycle to failure. The new NP-LP implant fixation is biomechanically comparable to the LC-SCP in a simulated MC3 fracture.

Bending strength and stiffness of wide dimension southern pine No. 2 lumber

2014 ◽  
Vol 72 (6) ◽  
pp. 759-768 ◽  
Author(s):  
Joseph Dahlen ◽  
P. David Jones ◽  
R. Daniel Seale ◽  
Rubin Shmulsky
Keyword(s):  
Bending Strength ◽  
Southern Pine ◽  
Strength And Stiffness

Prediction of bending strength and stiffness strength of particleboard based on structural parameters by Buckingham’s p-theorem

2010 ◽  
Vol 7 (1-2) ◽  
pp. 65-70 ◽  
Author(s):  
Mohammad Arabi ◽  
Mehdi Faezipour ◽  
Mohammad Layeghi ◽  
Akbar Enayati ◽  
Reza Zahed
Keyword(s):  
Bending Strength ◽  
Structural Parameters ◽  
Strength And Stiffness

scholarly journals Bending Strength and Stiffness of a Particulate Composite Material Manufactured with Epoxy Matrix and Corymbia Citriodora Sawdust

2013 ◽  
Vol 3 (4) ◽  
pp. 108-113
Author(s):  
Pascoal Hélder Rafael Santos ◽  
Filho Sergio Luiz Moni Ribeiro ◽  
Sousa Geraldo Roberto de ◽  
Lahr Francisco Antonio Rocco ◽  
Christoforo André Luís
Keyword(s):  
Composite Material ◽  
Epoxy Matrix ◽  
Bending Strength ◽  
Particulate Composite ◽  
Strength And Stiffness ◽  
Corymbia Citriodora ◽  
Particulate Composite Material

BENDING STRENGTH AND STIFFNESS OF NO. 2 GRADE SOUTHERN PINE LUMBER

2018 ◽  
Vol 50 (2) ◽  
pp. 205-219 ◽  
Author(s):  
T.S.F.A. França ◽  
F.J.N. França ◽  
R.D. Seale ◽  
R. Shmulsky
Keyword(s):  
Bending Strength ◽  
Southern Pine ◽  
Strength And Stiffness ◽  
Pine Lumber ◽  
Southern Pine Lumber

scholarly journals Mixed Visual and Machine Grading to Select Eucalyptus grandis Poles into High-Strength Classes

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1804
Author(s):  
Michele Brunetti ◽  
Giovanni Aminti ◽  
C. Brand Wessels ◽  
Michela Nocetti
Keyword(s):  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Bending Strength ◽  
Eucalyptus Grandis ◽  
High Strength ◽  
Multivariate Regression Analysis ◽  
Acoustic Velocity ◽  
Dynamic Modulus Of Elasticity ◽  
Graded Material ◽  
Strength And Stiffness

Before round timber can be profitably used in construction, it needs structural characterization. The visual grading of Eucalyptus grandis poles was integrated with additional parameters developed by multivariate regression analysis. Acoustic velocity and dynamic modulus of elasticity were combined with density and pole diameter in the estimation of bending strength and stiffness. The best models achieved were used to group the visually graded material into qualitative structural classes. Overall, dynamic modulus of elasticity was the best single predictor; and adding density and diameter to the model improved the estimation of strength but not of stiffness. The developed parameters separated the material into two classes with very distinct mechanical properties. The models including velocity as a parameter did not perform as well. The strength grading of Eucalyptus grandis poles can be effectively improved by combining visual parameters and nondestructive measurements. The determination of the dynamic modulus of elasticity as a grading parameter should be preferred over that of acoustic velocity.

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