scholarly journals Femoral Periprosthetic Fracture Treatment Using the Ortho-Bridge System: A Biomechanical Study

2021 ◽  
Author(s):  
wen wang ◽  
Yuntao Long ◽  
Yubin Qi ◽  
Guilai Zuo ◽  
Qingjie Zhang ◽  
...  
Keyword(s):  
Axial Compression ◽  
Torsion Angle ◽  
Periprosthetic Fracture ◽  
Failure Modes ◽  
Fracture Site ◽  
Biomechanical Study ◽  
Compression Failure ◽  
System P ◽  
Significant Difference ◽  
Bridge System

Abstract Background: We undertook a comparative biomechanical study of type B1 fractures around the femoral prosthesis following cemented hip arthroplasty using the Ortho-Bridge System (OBS) and a locking compression plate/locking attachment plate structure (LCP+LAP), and aimed to determine the effectiveness and advantages of the OBS when treating this fracture type. Methods: An OBS fixation model was designed based on OBS and LCP+LAP fixation characteristics. The LCP+LAP combination (Group A) and three different OBS combinations (Groups B, C, and D) were used to fix a B1 fracture model with a femoral periprosthetic fracture. Axial compression and torsion experiments were then performed using simple and comminuted fracture models. We conducted axial compression failure, model stiffness, and torsion angle tests, and tested the vertical load of final failure. Results: When simulating simple oblique fractures, no significant difference was found in terms of stiffness between the four groups in the axial compression experiment (P = 0.257). The torsion angle of the LCP+LAP system was significantly higher than that of the OBS (P < 0.05); however, there was no significant difference in the torsion angle between the OBS combinations (P > 0.05). Axial compression experimental data showed that stiffness in the three OBS combinations was higher than that in the LCP+LAP system (P = 0.000). Torsion angles of the three OBS combinations were smaller than those of the LCP+LAP system (P < 0.05). In the axial compression failure test, the fixed failure mode in the LCP+LAP system involved destruction of the contact cortex at the fracture site, while the failure modes in the three OBS combinations involved destruction of the contact cortex at the fracture site and the fracture around the screws above the osteotomy. Conclusion: Compared with the LCP+LAP, the OBS showed superior biomechanical results. Furthermore, the OBS has the advantage of multiple choices and high flexibility of combinations. Stress dispersion was helpful in avoiding internal fixation failure during early postoperative functional exercise.

scholarly journals Investigating the biomechanics function of the plate-type external fixator in the treatment of tibial fractures: a biomechanical study

2019 ◽  
Author(s):  
Di Shi ◽  
Kaiyuan Liu ◽  
Haomeng Zhang ◽  
Xinli Wang ◽  
Guochen Li ◽  
...  
Keyword(s):  
Axial Compression ◽  
External Fixator ◽  
Failure Modes ◽  
Biomechanical Properties ◽  
Biomechanical Study ◽  
Four Point Bending ◽  
Low Profile ◽  
Load Mode ◽  
The Stability ◽  
Plate Type

Abstract Background People have been pursuing to design an external fixator with the optimal biomechanics function and the lowest profile, since the fracture healing is dependent on the stability and durability of fixation and a low profile is more acceptable to patients. The plate-type external fixator, a novel prototype of an external tibial fixation device, is a low profile construct. However, the biomechanical properties remained unclear. The objective of the study was to investigate stiffness and strength of the plate-type external fixator and the unilateral external fixator. We hypothesized that the plate-type external fixator could provide higher stiffness, while retaining sufficient strength. Methods Fifty-four cadaver tibias underwent a standardized midshaft osteotomy to create a fracture gap model to simulate a comminuted diaphyseal fracture. All specimens were randomly divided into three groups of eighteen specimens each and stabilized with either the unilateral external fixator or the two configurations of the plate-type external fixator. Six specimens of each configuration were tested to determine fixation stiffness in axial compression, four-point bending, and torsion, respectively. Afterwards, dynamically loading until failure was performed in each load mode to determine construct strength and failure modes. Results The plate-type external fixator provided higher stiffness and strength compared with the traditional unilateral external fixator. The highest biomechanics was observed for the classical plate-type external fixator, with the extended plate-type external fixator close behind. Conclusions The plate-type external fixator is stiffer and stronger than the traditional unilateral external fixator under axial compression, four-point bending and torsion loading conditions.

scholarly journals Interference Screw Versus Suture Anchors for Femoral Fixation in Medial Patellofemoral Ligament Reconstruction: A Biomechanical Study

2021 ◽  
Vol 9 (3) ◽  
pp. 232596712198928
Author(s):  
Heath P. Gould ◽  
Nicholas R. Delaney ◽  
Brent G. Parks ◽  
Roshan T. Melvani ◽  
Richard Y. Hinton
Keyword(s):  
Medial Patellofemoral Ligament ◽  
Interference Screw ◽  
Biomechanical Study ◽  
Graft Fixation ◽  
Mpfl Reconstruction ◽  
Suture Anchors ◽  
Femoral Fixation ◽  
Significant Difference ◽  
Load To Failure ◽  
The Mean

Background: Femoral-sided graft fixation in medial patellofemoral ligament (MPFL) reconstruction is commonly performed using an interference screw (IS). However, the IS method is associated with several clinical disadvantages that may be ameliorated by the use of suture anchors (SAs) for femoral fixation. Purpose: To compare the load to failure and stiffness of SAs versus an IS for the femoral fixation of a semitendinosus autograft in MPFL reconstruction. Study Design: Controlled laboratory study. Methods: Based on a priori power analysis, a total of 6 matched pairs of cadaveric knees were included. Specimens in each pair were randomly assigned to receive either SA or IS fixation. After an appropriate reconstruction procedure, the looped end of the MPFL graft was pulled laterally at a rate of 6 mm/s until construct failure. The best-fit slope of the load-displacement curve was then used to calculate the stiffness (N/mm) in a post hoc fashion. A paired t test was used to compare the mean load to failure and the mean stiffness between groups. Results: No significant difference in load to failure was observed between the IS and the SA fixation groups (294.0 ± 61.1 vs 250.0 ± 55.9; P = .352), although the mean stiffness was significantly higher in IS specimens (34.5 ± 9.6 vs 14.7 ± 1.2; P = .004). All IS reconstructions failed by graft pullout from the femoral tunnel, whereas 5 of the 6 SA reconstructions failed by anchor pullout. Conclusion: In this biomechanical study using a cadaveric model of MPFL reconstruction, SA femoral fixation was not significantly different from IS fixation in terms of load to failure. The mean load-to-failure values for both reconstruction techniques were greater than the literature-reported values for the native MPFL. Clinical Relevance: These results suggest that SAs are a biomechanically viable alternative for femoral-sided graft fixation in MPFL reconstruction.

A COMPARATIVE BIOMECHANICAL STUDY OF THE LOOPED SQUARE SLIP KNOT AND THE SIMPLE SURGICAL KNOT

Hand Surgery ◽  
2006 ◽  
Vol 11 (01n02) ◽  
pp. 93-99 ◽  
Author(s):  
Surut Jianmongkol ◽  
Geoffrey Hooper ◽  
Weerachai Kowsuwon ◽  
Tala Thammaroj
Keyword(s):  
Ultimate Strength ◽  
Hand Surgery ◽  
Biomechanical Properties ◽  
Biomechanical Study ◽  
Skin Closure ◽  
Significant Difference ◽  
Mode Of Failure ◽  
Repetitive Loading ◽  
Slip Knot

The looped square slip knot was introduced as a technique for skin closure to avoid the use of sharp instruments in suture removal after hand surgery. We compared the biomechanical properties of this knot with the simple surgical square knot. The ultimate strength of the looped square slip knot was significantly (p = 0.015) higher than the simple surgical knot. There was no significant difference between the two knots in mode of failure. Knot slippage or suture breakage did not occur in any samples when testing security by repetitive loading. Therefore, the looped square slip knot is a safe and convenient alternative to the two-throw surgical knot for use in hand surgery.

The Effect of Thickness on the Fracture Strength and Failure Modes of Zirconia Crowns

2016 ◽  
Vol 697 ◽  
pp. 629-632
Author(s):  
Li Xian Zhang ◽  
Rui Li ◽  
Yu Niu ◽  
Yu Xiao Liu
Keyword(s):  
Fracture Strength ◽  
Failure Modes ◽  
Statistical Significance ◽  
Dental Practice ◽  
Significant Difference ◽  
Cad Cam ◽  
Zirconia Crowns ◽  
Different Thickness

To explore the effect of thickness on the fracture strength and failure modes of zirconia crowns, four crown models with different thickness (1.2 mm, 1.0 mm, 0.8 mm, 0.6 mm) with the same shape were designed by Dental Designer software in CAD/CAM system. They were manufactured to 40 zirconia crowns by CAM carving machine. The fracture strength and the failure modes of each crown was measured, while porcelain fused to metal (PFM) crowns as control. The average fracture strength of different zirconia crowns were recorded as below: 1308.38 ± 111.38 N (Group 0.6 mm), 1841.60 ± 68.21 N (Group 0.8 mm), 2429.88 ± 315.03 N (Group 1.0 mm), 3068.31 ± 233.88 N (Group 1.2 mm). There was no significant difference between Group 1.0 mm and Group 1.2 mm (P > 0.05), and statistical significance was obtained among every other two groups (P < 0.05). The failure modes of different thickness zirconium crowns are similar. There are more broken pieces from thicker crowns compared to thinner ones. It is concluded that the thickness can influence the fracture strength of zirconia crown. With the increase of the thickness, the fracture strength of the zirconium crowns also increases. We recommend zirconia crowns thicker than or at least 1.0 mm in dental practice.

In vitro biomechanical comparison of load to failure testing of a canine unconstrained medial compartment elbow arthroplasty system and normal canine thoracic limbs

2013 ◽  
Vol 26 (05) ◽  
pp. 356-365 ◽  
Author(s):  
K. L. Wendelburg ◽  
S. Tepic ◽  
S. M. Stover ◽  
T. Garcia-Nolen ◽  
P. B. Stearns ◽  
...  
Keyword(s):  
Axial Load ◽  
Failure Modes ◽  
Ex Vivo ◽  
Medial Compartment ◽  
Elbow Arthroplasty ◽  
Total Arthroplasty ◽  
Significant Difference ◽  
Load To Failure ◽  
And Control

SummaryElbow dysplasia, primarily affecting the medial compartment, is the most common cause of lameness in the thoracic limb. Elbow arthroplasty is an option for end stage or severely affected patients. The purpose of this study was to compare ex vivo axial load to failure of an implanted novel elbow arthroplasty system to control limbs. The partial arthroplasty is a medial compartmental, unconstrained system, intended to allow conversion to total arthroplasty. We hypothesized that there would not be any significant difference between implanted and controlled limbs when loaded to failure. Six pairs of medium mixed breed canine cadaveric thoracic limbs were prepared for comparison of failure loading of control and implanted limbs. Axial compression was performed using a mechanical testing system. Failure loads were normalized to bodyweight. The mean normalized failure load (N/kg) for the implanted limbs and control limbs were 2.47 (range: 1.62-3.38) and 2.68 (range: 2.25-3.25), respectively. An implanted to control ratio of 0.93 ± 0.19 was calculated. The difference between paired control and implanted limbs in normalized failure loading was not significant (p = 0.38). There were not any differences noted in the yield load (p = 0.30), stiffness (p = 0.62), or energy (0.58). Failure modes were recorded. We concluded that the differences between implanted and control limbs in supra-physiologic axial load to failure were not significant.

scholarly journals Effect of Surface Treatments on the Bond Strength to Turkom-Cera All-ceramic Material

2016 ◽  
Vol 17 (11) ◽  
pp. 920-925 ◽  
Author(s):  
Bandar MA Al-Makramani ◽  
Fuad A Al-Sanabani ◽  
Abdul AA Razak ◽  
Mohamed I Abu-Hassan ◽  
Ibrahim Z AL-Shami ◽  
...  
Keyword(s):  
Bond Strength ◽  
Ceramic Material ◽  
Failure Modes ◽  
Testing Machine ◽  
Surface Treatments ◽  
Resin Cement ◽  
Control Group ◽  
Significant Difference ◽  
All Ceramic ◽  
Effect Of Surface

ABSTRACT Aim The aim of this study was to evaluate the effect of surface treatments on shear bond strength (SBS) of Turkom-Cera (Turkom-Ceramic (M) Sdn. Bhd., Puchong, Malaysia) all-ceramic material cemented with resin cement Panavia-F (Kuraray Medical Inc., Okayama, Japan). Materials and methods Forty Turkom-Cera ceramic disks (10 mm × 3 mm) were prepared and randomly divided into four groups. The disks were wet ground to 1000-grit and subjected to four surface treatments: (1) No treatment (Control), (2) sandblasting, (3) silane application, and (4) sandblasting + silane. The four groups of 10 specimens each were bonded with Panavia-F resin cement according to manufacturer's recommendations. The SBS was determined using the universal testing machine (Instron) at 0.5 mm/min crosshead speed. Failure modes were recorded and a qualitative micromorphologic examination of different surface treatments was performed. The data were analyzed using the one-way analysis of variance (ANOVA) and Tukey honestly significant difference (HSD) tests. Results The SBS of the control, sandblasting, silane, and sandblasting + silane groups were: 10.8 ± 1.5, 16.4 ± 3.4, 16.2 ± 2.5, and 19.1 ± 2.4 MPa respectively. According to the Tukey HSD test, only the mean SBS of the control group was significantly different from the other three groups. There was no significant difference between sandblasting, silane, and sandblasting + silane groups. Conclusion In this study, the three surface treatments used improved the bond strength of resin cement to Turkom-Cera disks. Clinical significance The surface treatments used in this study appeared to be suitable methods for the cementation of glass infiltrated all-ceramic restorations. How to cite this article Razak AAA, Abu-Hassan MI, AL-Makramani BMA, AL-Sanabani FA, AL-Shami IZ, Almansour HM. Effect of Surface Treatments on the Bond Strength to Turkom-Cera All-Ceramic Material. J Contemp Dent Pract 2016;17(11):920-925.

The Peroneal Groove Deepening Procedure: A Biomechanical Study of Pressure Reduction

2005 ◽  
Vol 26 (6) ◽  
pp. 442-448 ◽  
Author(s):  
Craig I. Title ◽  
Hung-Geun Jung ◽  
Brent G. Parks ◽  
Lew C. Schon
Keyword(s):  
Biomechanical Study ◽  
Posterior Tibial Tendon ◽  
Peroneal Tendon ◽  
Foot And Ankle ◽  
Calcaneofibular Ligament ◽  
Significant Difference ◽  
Mean Pressure ◽  
Fresh Frozen ◽  
The Mean ◽  
Pressure Changes

Background: The goal of this study was to identify pressure changes throughout the peroneal groove after a groove deepening procedure. We hypothesized that pressures would decrease. Methods: Twelve fresh-frozen foot and ankle specimens were used. A thin pressure strip containing four sensor pads was secured within the peroneal groove with pads 1 through 4 positioned at the calcaneofibular ligament (CFL) and at the distal, middle, and proximal groove, respectively. The midstance phase of gait was simulated with loads applied to the plantar foot and posterior tibial tendon and to the peroneus longus and brevis tendons. Pressures were recorded with the ankle in neutral, plantarflexion, dorsiflexion, inversion, and eversion. Groove deepening was done by osteotomizing the posterior fibular wall. Pressure readings were then recorded. Average pressures for each of the four sensor pads after the procedure were compared to those obtained before the procedure. Results: The mean pressure overlying the CFL increased at all five ankle positions; however, these changes were not significant. Significant decreases in pressure were noted within the distal and middle groove at all ankle positions after the peroneal groove deepening procedure. Pressure within the proximal groove increased at all but one position, with a significant difference noted in neutral and plantarflexion. Conclusion: Pressures within the middle and distal peroneal groove significantly decreased after a groove deepening procedure. Combining this technique with peroneal tendon debridement may be advantageous for treatment of partial peroneal tendon tears or recalcitrant peroneal tendinitis.

C-section Cold-Formed Steel as Structural Members in Housing Construction in the Philippines

2019 ◽  
Author(s):  
Bernardo A. Lejano
Keyword(s):  
Axial Compression ◽  
High Speed ◽  
Failure Modes ◽  
Weight Ratio ◽  
High Strength ◽  
The Philippines ◽  
Bending Test ◽  
Housing Construction ◽  
Distortional Buckling ◽  
Cold Formed Steel

<p>Getting good lumber for housing construction is becoming difficult in the Philippines due to existing partial log ban. Although, the use of reinforced concrete is still the most popular in construction, an emerging alternative is the use of cold-formed steel (CFS). It is gaining popularity because of its high strength-to- weight ratio. However, information about the structural performance of locally-produced cold-formed steel is almost nonexistent. Although, design provisions are stipulated in the local Code, these are based on formulas developed abroad, hence the need to investigate these cold-formed steel. This study focuses on the C-section cold-formed steel, which is the most popularly used. The objective is to verify its performance when subjected to axial compression and flexure, both experimentally and computationally. For the computational part, the formulas stipulated in the National Structural Code of the Philippines were followed. For the experimental part, the cold-formed steel members were subjected to compression loads and flexural loads. Aside from usual sensors, high-speed cameras were used to capture the failure modes. For axial compression test, 80 specimens with different lengths and thicknesses were tested. For flexure, 24 specimens of back-to-back C-sections were subjected to 4-point bending test. Results showed the predicted strengths were well below the experimental values. In design, this means the use of Code-based formulas is conservative. Failure modes observed were torsional buckling and distortional buckling. Comparison of failure modes between experiment and computation shows 70% agreement for compression and 75% for flexure. Finite element method calculations were also done and were compared with experimental results.</p>

Structure behavior of concrete filled double-steel-plate composite walls under fire

2019 ◽  
Vol 22 (8) ◽  
pp. 1895-1908
Author(s):  
Fangfang Wei ◽  
Zejun Zheng ◽  
Jun Yu ◽  
Yongquan Wang
Keyword(s):  
Axial Compression ◽  
Compression Ratio ◽  
Axial Load ◽  
Failure Modes ◽  
Steel Plate ◽  
Local Buckling ◽  
Engineering Practice ◽  
Axial Compression Ratio ◽  
Fire Endurance ◽  
Composite Walls

Concrete filled double-steel-plate composite walls with shear studs, one type of steel–concrete–steel walls, are recently developed and have been used in high-rise buildings, for which fire safety is a big concern. In order to investigate the fire endurance of this new type of concrete filled double-steel-plate composite walls, three specimens with different axial compression ratios and different lengths and intervals of shear studs were tested under one-side ISO-834 standard fire to obtain the temperature distribution, deformation, and detailed failure modes. Each specimen consisted of a concrete filled double-steel-plate composite wall-body and two boundary columns. Moreover, finite-element-based numerical investigations were conducted to confirm and extend experimental findings. All the concrete filled double-steel-plate composite walls failed in compression–flexure mode with the local buckling at the compressive steel plate. The results indicate that the fire endurance of concrete filled double-steel-plate composite walls is significantly affected by the axial compression ratio, the eccentricity of the axial load, and the bond strength between shear studs and concrete. Axial compression ratio, defined as the ratio of axial compression to the nominal compressive capacity of concrete filled double-steel-plate composite walls, has both positive and negative effects on the fire endurance of concrete filled double-steel-plate composite walls. The axial load eccentricity toward the unexposed side is much more detrimental to the fire endurance of concrete filled double-steel-plate composite walls than the one toward the exposed side. In engineering practice, it is recommended that proper intervals (not greater than 300 mm) and lengths (not less than 40 mm) of the shear studs should be used to ensure the bond between concrete and steel plates.

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