A combined experimental and computational study of mechanical properties after balloon kyphoplasty

2021 ◽  
pp. 095441192110139
Author(s):  
Philip Purcell ◽  
Fiona McEvoy ◽  
Stephen Tiernan ◽  
Derek Sweeney ◽  
Seamus Morris
Keyword(s):  
Computational Models ◽  
Computational Study ◽  
Case Reports ◽  
Experimental Tests ◽  
Balloon Kyphoplasty ◽  
Fatigue Tests ◽  
Vertebral Compression Fractures ◽  
Baseline Case ◽  
Strength And Stiffness ◽  
Stiffness Loss

Vertebral compression fractures rank among the most frequent injuries to the musculoskeletal system, with more than 1 million fractures per annum worldwide. The past decade has seen a considerable increase in the utilisation of surgical procedures such as balloon kyphoplasty to treat these injuries. While many kyphoplasty studies have examined the risk of damage to adjacent vertebra after treatment, recent case reports have also emerged to indicate the potential for the treated vertebra itself to re-collapse after surgery. The following study presents a combined experimental and computational study of balloon kyphoplasty which aims to establish a methodology capable of evaluating these cases of vertebral re-collapse. Results from both the experimental tests and computational models showed significant increases in strength and stiffness after treatment, by factors ranging from 1.44 to 1.93, respectively. Fatigue tests on treated specimens showed a 37% drop in the rate of stiffness loss compared to the untreated baseline case. Further analysis of the computational models concluded that inhibited PMMA interdigitation at the interface during kyphoplasty could reverse improvements in strength and stiffness that could otherwise be gained by the treatment.

scholarly journals Interlocking birch plywood structures

2021 ◽  
pp. 095605992110222
Author(s):  
Chrysl A Aranha ◽  
Markus Hudert ◽  
Gerhard Fink
Keyword(s):  
High Surface ◽  
Surface Hardness ◽  
Experimental Tests ◽  
Digital Fabrication ◽  
Element Model ◽  
Component Level ◽  
Geometrical Properties ◽  
Stiffness Properties ◽  
The Face ◽  
Strength And Stiffness

Interlocking Particle Structures (IPS) are geometrically stable assemblies, usually fabricated from plate type elements that are interconnected by slotted joints. IPS are demountable and their components have the potential to be used and reused in different structures and configurations. This paper explores the applicability of birch plywood panels, which are characterized by a high surface hardness, for this type of structural system. Experimental tests were conducted to determine the mechanical properties of birch plywood plates. Moreover, IPS connections with different geometrical properties were investigated for two different load exposures: bending and rotation. The characteristics under bending exposure are influenced by the orientation of the face-veneers. For the rotational load exposure, very small strength and stiffness properties have been identified. A linear elastic finite element model is presented that shows a wide agreement with the test results. The study serves as an initial probe into the performance of IPS structures at the component level. Various aspects that are relevant for the design of IPS, such as the assembly, the accuracy and challenges regarding digital fabrication, the durability, and the structural performance are discussed.

O-Arm–Guided Balloon Kyphoplasty: Prospective Single-Center Case Series of 54 Consecutive Patients

2011 ◽  
Vol 68 (suppl_2) ◽  
pp. ons250-ons256 ◽  
Author(s):  
Frédéric Schils
Keyword(s):  
Case Series ◽  
Balloon Kyphoplasty ◽  
Guidance System ◽  
Fluoroscopy Time ◽  
Vertebral Compression Fractures ◽  
Additional Time ◽  
Minimally Invasive Spinal Surgery ◽  
X Ray ◽  
Clinical Series ◽  
The Mean

Abstract Background: Balloon kyphoplasty is widely used to treat vertebral compression fractures. Procedure outcome and safety are directly linked to precise radiological imaging requiring 1 or 2 C arms to allow correct visualization throughout the procedure. This minimally invasive spinal surgery is associated with radiation exposure for both patient and surgeon. In our center, we switched from using a C-arm to an O-arm image guidance system to perform balloon kyphoplasty. Our preliminary experience is reported in Acta Neurochirurgica, and the encouraging results led us to study this subject more extensively. This article presents our complete results. To the best of our knowledge, there is no comparable clinical series describing O-arm use in kyphoplasty procedures published in the literature. Objective: To report our complete results of using the O-arm guidance system to perform balloon kyphoplasty. Methods: We prospectively evaluated O-arm–guided kyphoplasty procedure in 54 consecutive patients and measured x-ray exposure and fluoroscopy time. Results: The mean surgical time for the procedure was 38 minutes with a mean fluoroscopy procedure time of 3.1 minutes. The mean fluoroscopy time by level was 2.5 minutes. Mean irradiation dose by procedure was 220 mGy and by level was 166 mGy. There was a significant reduction in fluoroscopy time and x-ray exposure from 5.1 minutes with classic C-arm use to 3.1 minutes when with O-arm use without additional time required for positioning the system. Conclusion: With this new intraoperative system, the overall surgical and fluoroscopy times can be further reduced in the near future.

FATIGUE FAILURE OF FIBROUS COMPOSITE BASED ON MULTISCALE APPROACH

2021 ◽  
Author(s):  
LAUREN KADLEC ◽  
CASSANDRA HALLER ◽  
YOUNG KWON ◽  
SOO-JEONG PARK ◽  
YUN-HAE KIM
Keyword(s):  
Fatigue Failure ◽  
Fibrous Composite ◽  
Fatigue Tests ◽  
Multiscale Approach ◽  
Failure Model ◽  
Successful Completion ◽  
Constituent Material ◽  
Material Behaviors ◽  
Fatigue Data ◽  
Strength And Stiffness

A framework was presented for a fatigue failure model of fibrous composites using a multiscale approach, which uses the fatigue data of the fiber and matrix materials, respectively. Using this model, fatigue failure of fibrous composite materials and structures can be predicted from the constituent material behaviors. To that end, fiber bundles were tested under cyclic loading to determine their residual strength and stiffness. A successful completion of the model is expected to replace many fatigue tests as the configuration of the fibrous composite is varied.

scholarly journals Effectiveness of Balloon Kyphoplasty in Patients with Painful Vertebral Compression Fractures

2018 ◽  
Vol 07 (03) ◽  
Author(s):  
Cornelis Wilhelmus Jacobus van Tilburg ◽  
Johannes George Groeneweg ◽  
Dirk Leendert Stronks ◽  
Frank Johannes Petrus Maria Huygen
Keyword(s):  
Balloon Kyphoplasty ◽  
Vertebral Compression Fractures ◽  
Compression Fractures

scholarly journals Comparison Of FEA Simulations And Experimental Results For As-Built Additively Manufactured Dogbone Specimens

2021 ◽  
Author(s):  
Prathamesh Baikerikar ◽  
Cameron J Turner
Keyword(s):  
Fused Deposition Modeling ◽  
Experimental Tests ◽  
Continuum Models ◽  
Element Analysis ◽  
Fused Deposition ◽  
Accuracy And Precision ◽  
Structure Strength ◽  
Deposition Modeling ◽  
End Use ◽  
Strength And Stiffness

Abstract Parts built using Fused Deposition Modeling (FDM – an additive manufacturing technology) differ from their design model in terms of their microstructure and material properties. These differences lead to a certain amount of ambiguity regarding the structure, strength and stiffness of the final FDM part. Increasing use of FDM parts as end use products, necessitates accurate simulations and analyses during part design. However, analysis methods such as Finite Element Analysis, are used for analysis of continuum models, and may not accurately represent the non-continuous non-linear FDM parts. Therefore, it is necessary to determine the accuracy and precision of FEA for FDM parts. The goal of this study is to compare FEA simulations of the as-built geometries with the experimental tests of actual FDM parts. Dogbone geometries that include different infill patterns are tested under tensile loading and later simulated using FEA. This study found that FEA results are not always an accurate or reliable means of predicting FDM part behaviors.

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