Effect of alar ligament transection in side-bending stress test: A cadaveric study

This research has focused on the evaluation of raw materials that used in the wings of modern airplane. These materials either would be fiberglass, carbon-fiber or aramid based composites like Kevlar. These common materials have been selected and evaluated depending on experimental data obtained from mechanical tests. These tests include: hardness, tensile strength and bending stress. The tests based on ASTM standards for mechanical properties. The results show increasing in the hardness value of graphite-epoxy by 9% comparing with that of fiberglass and by 18% comparing with that of Kevlar-epoxy. The results also show an increasing in the maximum tensile strength of graphite-epoxy by 2.9 times to that of fiberglass and by 5.5 times to that of Kevlar-epoxy. Furthermore, the results of bending stress test show increasing of the maximum strength of Kevlar-epoxy by 30% comparing to that of glass fiber and by 75% comparing to that of graphite-epoxy.

Download Full-text

Construct Validity of Clinical Tests for Alar Ligament Integrity: An Evaluation Using Magnetic Resonance Imaging

Physical Therapy ◽

10.2522/ptj.20110261 ◽

2012 ◽

Vol 92 (5) ◽

pp. 718-725 ◽

Cited By ~ 19

Author(s):

Peter G. Osmotherly ◽

Darren A. Rivett ◽

Lindsay J. Rowe

Keyword(s):

Magnetic Resonance Imaging ◽

Cervical Spine ◽

Magnetic Resonance ◽

Ligament Length ◽

Stress Tests ◽

Resonance Imaging ◽

Alar Ligament ◽

Alar Ligaments ◽

Side Bending ◽

Rotation Stress

Background The alar ligaments are integral to limiting occipito-atlanto-axial rotation and lateral flexion and enhancing craniocervical stability. Clinical testing of these ligaments is advocated prior to the application of some cervical spine manual therapy procedures. Given the absence of validation of these tests and the potential consequences if manipulation is applied to an unstable upper cervical spine segment, exploration of these tests is necessary. Objective The purpose of this study was to examine the direct effect of the side-bending and rotation stress tests on alar ligaments using magnetic resonance imaging (MRI). Design This was a within-participant experimental study. Methods Sixteen participants underwent MRI in neutral and end-range stress test positions using proton density-weighted sequences in a 3-Tesla system. Measurements followed a standardized protocol relative to the position of the axis. Distances were measured from dens tip to the inferior margin of the foramen magnum and from midsubstance of the dental attachment of the ligament to its occipital insertion. Between-side differences were calculated for each measurement to account for inherent asymmetries in morphology. Differences were compared between the test and neutral positions using a Wilcoxon signed rank test. Results Side-bending stress tests produced a median between-side difference in ligament length of +1.15 mm. Rotation stress tests produced a median between-side difference in ligament length of +2.08 mm. Both results indicate increased measurement of the contralateral alar ligament. Limitations Assessment could be made only in the neutral position due to imaging limitations. Clinical texts state that tests should be performed in 3 positions: neutral, flexion, and extension. Conclusions Both side-bending and rotation stress testing result in a measurable increase in length of the contralateral alar ligament. This finding is consistent with mechanisms that have been described to support their use in clinical practice.

Download Full-text

Study on Strength Calculation and Bend Stress Test of Face Gear

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.86.227 ◽

2011 ◽

Vol 86 ◽

pp. 227-231

Author(s):

Hong Mei Wu ◽

Xin Yuan Yang ◽

Yun Bo Shen

Keyword(s):

Stress Test ◽

Analytical Calculation ◽

Bending Stress ◽

Bend Strength ◽

Test Bed ◽

Face Gear ◽

Simulation Based ◽

Elasticity Equation ◽

Simulation Results ◽

Set Up

Based on normal elasticity equation, this paper has developed the calculation formula of face gear’s contact strength, bend strength and scuffing strength. This work put forward an analytical calculation method of face gear’s bend strength and constructed the analytical model. The result of bend strength of face gear was obtained by computer simulation. Based on the research, we designed and manufactured a suit of face gearbox. According to the tooth space trait, a method was represented to test bending stress of tooth by arrangement of sensing device in the tip end of the tooth of face gear. A test-bed has been set up with which the bending stress of tooth of face gear was carried out. The results showed that the maximal bending stress of test is similar to the simulation results by ANSYS.

Download Full-text

A novel method for internal fixation of basal fifth metatarsal fracture in athletes: a cadaveric study of the F.E.R.I. technique (Fifth metatarsal, Extra-portal, Rigid, Innovative)

Journal of Experimental Orthopaedics ◽

10.1186/s40634-019-0213-5 ◽

2019 ◽

Vol 6 (1) ◽

Cited By ~ 1

Author(s):

Pieter D’Hooghe ◽

Silvio Caravelli ◽

Simone Massimi ◽

James Calder ◽

Peter Dzendrowskyj ◽

...

Keyword(s):

Internal Fixation ◽

Stress Test ◽

Kirschner Wire ◽

Cadaveric Study ◽

Return To Play ◽

Non Union ◽

Kirschner Wire Fixation ◽

Satisfactory Outcome ◽

Novel Method ◽

Intramedullary Screw

Abstract Purpose One of the main problems of Kirschner wire fixation of fifth metatarsal base fractures (in combination with a tension band wiring technique) seems to be hardware intolerance and several studies in athletes also report failure after isolated fixation with a screw only. These reports prompted us to look at new materials and a novel technique through fixation with an intramedullary screw combined with a high-resistance suture via the presented F.E.R.I. (Fifth metatarsal, Extra-portal, Rigid, Innovative) technique. Methods This cadaveric study describes F.E.R.I. technique. On a cadaver, through two mini portals, a full reduction and solid internal fixation with an intramedullary screw and suture cerclage with Fiberwire of a fifth metatarsal base fracture is achieved. In this article, the cadaveric study and proposed surgical technique are explained and illustrated step by step. Results The presented internal fixation F.E.R.I. technique is indicated in acute proximal fractures, stress fractures or non-union of metatarsal 5 (Zone 2–3 by Lawrence and Botte) and it resulted feasible and stable during manual stress test. The authors intend to study this technique in the clinical setting in the near future. Conclusions Fifth metatarsal base fractures gain specific interest when occurring in athletes. In this group of patients, internal fixation is often required to obtain a satisfactory outcome and time to return to play. The aim of the presented cadaveric study is to illustrate an innovative concept of internal fixation, named F.E.R.I.

Download Full-text

Toward Understanding Normal Craniocervical Rotation Occurring During the Rotation Stress Test for the Alar Ligaments

Physical Therapy ◽

10.2522/ptj.20120266 ◽

2013 ◽

Vol 93 (7) ◽

pp. 986-992 ◽

Cited By ~ 6

Author(s):

Peter Grant Osmotherly ◽

Darren Rivett ◽

Lindsay J. Rowe

Keyword(s):

Stress Testing ◽

Stress Test ◽

Intraclass Correlation ◽

Reference Plane ◽

Neutral Position ◽

Alar Ligament ◽

Alar Ligaments ◽

Measurement Protocol ◽

Test Position ◽

Rotation Stress

Background The rotation stress test is recommended for assessing alar ligament integrity. Although some authors, in the literature regarding the rotation stress test, accept that rotation will occur during testing, estimates of range occurring with a normal test response vary between 20 and 40 degrees. None of these estimates are based on formal examination of the test. Objective The purposes of this study were: (1) to examine the range of craniocervical rotation occurring during rotation stress testing for the alar ligaments in individuals who are healthy and (2) to investigate a measurement protocol for quantifying rotation. Design A within-subject experimental study was conducted. Methods Sixteen participants underwent magnetic resonance imaging in neutral and end-range rotation stress test positions. Measurements followed a standardized protocol relative to the position of the axis. A line connecting the transverse foramena of the axis created a reference plane. The position of the occiput in the head-neutral position was calculated as the angle formed between a line joining the foramena lacerum and the reference plane. Measurements were repeated at the end-range test position. Total rotation of the occiput was calculated as the difference in angles measured in neutral and test positions. Measurement was performed on 4 occasions, and reliability of measurements was assessed using the standard error of measurement (SEM) and the intraclass correlation coefficient (ICC). Results Measurement of rotation of the occiput relative to a stabilized axis ranged between 1.7 and 21.5 degrees (X̅=10.6, SD=5.1, SEM=1.14, ICC=.96, 95% confidence interval=.90–.98). Limitations Sustaining the test position for imaging increased the potential for loss of end-range position and image quality. Testing could be performed only in the neutral position, not in 3 planes as commonly described. Conclusions The range of craniocervical rotation during rotation stress testing of intact alar ligaments should typically be 21 degrees or less. Rotation may be quantified using the method protocol outlined.

Download Full-text