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Mechanical Performance of Metallic Bone Screws Evaluated Using Bone Models

To evaluate mechanical performance properties of various types of cortical bone screw, cancellous bone screw, and locking bolt, we conducted torsional breaking and durability tests, screw driving torque tests into bone models, and screw pullout tests (crosshead speed: 10 mm/min) after driving torque...

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Autores principales: Okazaki, Yoshimitsu, Hayakawa, Emiko, Tanahashi, Kazumasa, Mori, Jun
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7663295/
https://www.ncbi.nlm.nih.gov/pubmed/33137908
http://dx.doi.org/10.3390/ma13214836
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author Okazaki, Yoshimitsu
Hayakawa, Emiko
Tanahashi, Kazumasa
Mori, Jun
author_facet Okazaki, Yoshimitsu
Hayakawa, Emiko
Tanahashi, Kazumasa
Mori, Jun
author_sort Okazaki, Yoshimitsu
collection PubMed
description To evaluate mechanical performance properties of various types of cortical bone screw, cancellous bone screw, and locking bolt, we conducted torsional breaking and durability tests, screw driving torque tests into bone models, and screw pullout tests (crosshead speed: 10 mm/min) after driving torque tests. The 2° proof and rupture torques of a screw, which were estimated from torque versus rotational angle curves, increased with increasing core diameter of the screw. The durability limit of metallic screws obtained by four-point bending durability tests increased with increasing core diameter. The compressive, tensile, and shear strengths of the bone models used for the mechanical testing of orthopedic devices increased with increasing density of the bone model. The strength and modulus obtained for solid rigid polyurethane foam (SRPF) and cellular rigid polyurethane foam (CRPF) lay on the same straight line. Among the three strengths, the rate of increase in compressive strength with the increase in density was the highest. The maximum torque obtained by screw driving torque tests for up to 8.3 rotations (3000°) into the bone models tended to increase with increasing core diameter. In particular, the maximum torque increased linearly with increasing effective surface area of the screw, as newly defined in this work. The maximum pullout load increased linearly with increasing number of rotations and mechanical strength of the bone model. Screws with low driving torque and high pullout load were considered to have excellent fixation and are a target for development.
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spelling pubmed-76632952020-11-14 Mechanical Performance of Metallic Bone Screws Evaluated Using Bone Models Okazaki, Yoshimitsu Hayakawa, Emiko Tanahashi, Kazumasa Mori, Jun Materials (Basel) Article To evaluate mechanical performance properties of various types of cortical bone screw, cancellous bone screw, and locking bolt, we conducted torsional breaking and durability tests, screw driving torque tests into bone models, and screw pullout tests (crosshead speed: 10 mm/min) after driving torque tests. The 2° proof and rupture torques of a screw, which were estimated from torque versus rotational angle curves, increased with increasing core diameter of the screw. The durability limit of metallic screws obtained by four-point bending durability tests increased with increasing core diameter. The compressive, tensile, and shear strengths of the bone models used for the mechanical testing of orthopedic devices increased with increasing density of the bone model. The strength and modulus obtained for solid rigid polyurethane foam (SRPF) and cellular rigid polyurethane foam (CRPF) lay on the same straight line. Among the three strengths, the rate of increase in compressive strength with the increase in density was the highest. The maximum torque obtained by screw driving torque tests for up to 8.3 rotations (3000°) into the bone models tended to increase with increasing core diameter. In particular, the maximum torque increased linearly with increasing effective surface area of the screw, as newly defined in this work. The maximum pullout load increased linearly with increasing number of rotations and mechanical strength of the bone model. Screws with low driving torque and high pullout load were considered to have excellent fixation and are a target for development. MDPI 2020-10-29 /pmc/articles/PMC7663295/ /pubmed/33137908 http://dx.doi.org/10.3390/ma13214836 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Okazaki, Yoshimitsu
Hayakawa, Emiko
Tanahashi, Kazumasa
Mori, Jun
Mechanical Performance of Metallic Bone Screws Evaluated Using Bone Models
title Mechanical Performance of Metallic Bone Screws Evaluated Using Bone Models
title_full Mechanical Performance of Metallic Bone Screws Evaluated Using Bone Models
title_fullStr Mechanical Performance of Metallic Bone Screws Evaluated Using Bone Models
title_full_unstemmed Mechanical Performance of Metallic Bone Screws Evaluated Using Bone Models
title_short Mechanical Performance of Metallic Bone Screws Evaluated Using Bone Models
title_sort mechanical performance of metallic bone screws evaluated using bone models
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7663295/
https://www.ncbi.nlm.nih.gov/pubmed/33137908
http://dx.doi.org/10.3390/ma13214836
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