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Placement-induced effects on high tibial osteotomized construct - biomechanical tests and finite-element analyses
BACKGROUND: High tibial osteotomy (HTO) with a medially opening wedge has been used to treat osteoarthritic knees. However, the osteotomized tibia becomes a highly unstable structure and necessitates the use of plate and screws to stabilize the medial opening and enhance bone healing. A T-shaped pla...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
BioMed Central
2015
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4559000/ https://www.ncbi.nlm.nih.gov/pubmed/26337985 http://dx.doi.org/10.1186/s12891-015-0630-2 |
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author | Luo, Chu-An Hwa, Su-Yang Lin, Shang-Chih Chen, Chun-Ming Tseng, Ching-Shiow |
author_facet | Luo, Chu-An Hwa, Su-Yang Lin, Shang-Chih Chen, Chun-Ming Tseng, Ching-Shiow |
author_sort | Luo, Chu-An |
collection | PubMed |
description | BACKGROUND: High tibial osteotomy (HTO) with a medially opening wedge has been used to treat osteoarthritic knees. However, the osteotomized tibia becomes a highly unstable structure and necessitates the use of plate and screws to stabilize the medial opening and enhance bone healing. A T-shaped plate (e.g. TomoFix) with locking screws has been extensively used as a stabilizer of the HTO wedge. From the biomechanical viewpoint, however, the different plate sites and support bases of the HTO plate should affect the load-transferring path and wedge-stabilizing ability of the HTO construct. This study uses biomechanical tests and finite-element analyses to evaluate the placement- and base-induced effects of the HTO plates on construct performance. METHODS: Test-grade synthetic tibiae are chosen as the standard specimens of the static tests. A medial wedge is created for each specimen and stabilized by three plate variations: hybrid use of T- and I-shaped plates (TIP), anteriorly placed TomoFix (APT), and medially placed TomoFix (MPT). There are five tests for each variation. The failure loads of the three constructs are measured and used as the load references of the fatigue finite-element analysis. The residual life after two hundred thousand cycles is predicted for all variations. RESULTS: The testing results show no occurrence of implant back-out and breakage under all variations. However, the wedge fracture consistently occurs at the opening tip for the APT and MPT and the medially resected plateau for the TIP, respectively. The testing results reveal that both failure load and wedge stiffness of the TIP are the highest, followed by the MPT, while those of the APT are the least (P < 0.05). The fatigue analyses predict comparable values of residual life for the TIP and MPT and the highest value of damage accumulation for the APT. Both experimental and numerical tests show the biomechanical disadvantage of the APT than their counterparts. However, the TIP construct without locking screws shows the highest stress at the plate-screw interfaces. CONCLUSIONS: This study demonstrates the significant effect of placement site and support base on the construct behaviors. The TIP provides a wider base for supporting the HTO wedge even without the use of locking screws, thus significantly enhancing construct stiffness and suppressing wedge fracture. Compared to the APT, the MPT shows performance more comparable to that of the TIP. If a single plate and a smaller incision are considered, the MPT is recommended as the better alternative for stabilizing the medial HTO wedge. |
format | Online Article Text |
id | pubmed-4559000 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-45590002015-09-04 Placement-induced effects on high tibial osteotomized construct - biomechanical tests and finite-element analyses Luo, Chu-An Hwa, Su-Yang Lin, Shang-Chih Chen, Chun-Ming Tseng, Ching-Shiow BMC Musculoskelet Disord Research Article BACKGROUND: High tibial osteotomy (HTO) with a medially opening wedge has been used to treat osteoarthritic knees. However, the osteotomized tibia becomes a highly unstable structure and necessitates the use of plate and screws to stabilize the medial opening and enhance bone healing. A T-shaped plate (e.g. TomoFix) with locking screws has been extensively used as a stabilizer of the HTO wedge. From the biomechanical viewpoint, however, the different plate sites and support bases of the HTO plate should affect the load-transferring path and wedge-stabilizing ability of the HTO construct. This study uses biomechanical tests and finite-element analyses to evaluate the placement- and base-induced effects of the HTO plates on construct performance. METHODS: Test-grade synthetic tibiae are chosen as the standard specimens of the static tests. A medial wedge is created for each specimen and stabilized by three plate variations: hybrid use of T- and I-shaped plates (TIP), anteriorly placed TomoFix (APT), and medially placed TomoFix (MPT). There are five tests for each variation. The failure loads of the three constructs are measured and used as the load references of the fatigue finite-element analysis. The residual life after two hundred thousand cycles is predicted for all variations. RESULTS: The testing results show no occurrence of implant back-out and breakage under all variations. However, the wedge fracture consistently occurs at the opening tip for the APT and MPT and the medially resected plateau for the TIP, respectively. The testing results reveal that both failure load and wedge stiffness of the TIP are the highest, followed by the MPT, while those of the APT are the least (P < 0.05). The fatigue analyses predict comparable values of residual life for the TIP and MPT and the highest value of damage accumulation for the APT. Both experimental and numerical tests show the biomechanical disadvantage of the APT than their counterparts. However, the TIP construct without locking screws shows the highest stress at the plate-screw interfaces. CONCLUSIONS: This study demonstrates the significant effect of placement site and support base on the construct behaviors. The TIP provides a wider base for supporting the HTO wedge even without the use of locking screws, thus significantly enhancing construct stiffness and suppressing wedge fracture. Compared to the APT, the MPT shows performance more comparable to that of the TIP. If a single plate and a smaller incision are considered, the MPT is recommended as the better alternative for stabilizing the medial HTO wedge. BioMed Central 2015-09-04 /pmc/articles/PMC4559000/ /pubmed/26337985 http://dx.doi.org/10.1186/s12891-015-0630-2 Text en © Luo et al. 2015 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/ (http://creativecommons.org/licenses/by/4.0) ), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. |
spellingShingle | Research Article Luo, Chu-An Hwa, Su-Yang Lin, Shang-Chih Chen, Chun-Ming Tseng, Ching-Shiow Placement-induced effects on high tibial osteotomized construct - biomechanical tests and finite-element analyses |
title | Placement-induced effects on high tibial osteotomized construct - biomechanical tests and finite-element analyses |
title_full | Placement-induced effects on high tibial osteotomized construct - biomechanical tests and finite-element analyses |
title_fullStr | Placement-induced effects on high tibial osteotomized construct - biomechanical tests and finite-element analyses |
title_full_unstemmed | Placement-induced effects on high tibial osteotomized construct - biomechanical tests and finite-element analyses |
title_short | Placement-induced effects on high tibial osteotomized construct - biomechanical tests and finite-element analyses |
title_sort | placement-induced effects on high tibial osteotomized construct - biomechanical tests and finite-element analyses |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4559000/ https://www.ncbi.nlm.nih.gov/pubmed/26337985 http://dx.doi.org/10.1186/s12891-015-0630-2 |
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