Concentrated stress effects of contoured and non-contoured high Tibial osteotomy plates: A finite-element study

Pei-Wei Weng; Chen-Kun Liaw; Chia-Hsien Chen; Chu-An Luo; Chih-Hwa Chen; Yang-Hwei Tsuang; Shang-Chih Lin

doi:10.1016/j.clinbiomech.2020.105089

Concentrated stress effects of contoured and non-contoured high Tibial osteotomy plates: A finite-element study

Clin Biomech (Bristol, Avon). 2020 Aug:78:105089. doi: 10.1016/j.clinbiomech.2020.105089. Epub 2020 Jun 11.

Authors

Pei-Wei Weng¹, Chen-Kun Liaw², Chia-Hsien Chen¹, Chu-An Luo³, Chih-Hwa Chen⁴, Yang-Hwei Tsuang⁵, Shang-Chih Lin⁶

Affiliations

¹ Department of Orthopaedics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Orthopaedics, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan; Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei, Taiwan.
² Department of Orthopaedics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Orthopaedics, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan.
³ Graduate Institute of Biomedical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan.
⁴ Department of Orthopaedics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan; Department of Orthopaedics, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan; Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei, Taiwan. Electronic address: chihhwache@tmu.edu.tw.
⁵ Department of Orthopaedics, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan.
⁶ Graduate Institute of Biomedical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan. Electronic address: biocax@ymail.com.

PMID: 32593906
DOI: 10.1016/j.clinbiomech.2020.105089

Abstract

Background: The TomoFix plate has been extensively used in high tibial osteotomy surgery to stabilize the distracted tibial bones. However, distal pain related to plate irritation was considered one of the most relevant complications for this fixation device. This study aimed to correlate reports of distal pain with the profiles of the distracted tibia and initial plate and plate contour.

Methods: This study used the finite-element method to investigate the profile-, distraction-, and contour-induced effects on stress distribution of the distal tibia-plate contact. The associations of two tibia profiles (normal and concave), distraction angles, and two plate profiles (contoured and non-contoured) were discussed in this study. The areas and stresses of the distal tibia-plate contact were chosen as comparison indices.

Findings: Before weight-bearing, the non-contoured plates of the normal and concave tibia profiles consistently showed less contact area at the distal tibia-plate region. Consequently, the physiological loads make the non-contoured plate subject to more concentrated bone stresses and thus may induce more pain at the distal tibia-plate region than a contoured plate. When the distraction angle decreases, the tibia-plate gap increases. Prior to fixation, the tibia-plate gap can be evaluated by the profiles of the distracted tibia and non-contoured plate by use of anteroposterior radiograph and computer-aided simulation.

Interpretation: In the situations of a lower distraction angle or a large tibia-plate gap, the use of a plate bender or a lag screw is recommended in order to contour the plate for reducing the concentrated stress at the distal tibia-plate region.

Keywords: Concentrated stress; Contoured plate; Distal pain; High tibial osteotomy; TomoFix plate.

MeSH terms

Bone Plates*
Bone Screws
Computer Simulation
Female
Finite Element Analysis*
Humans
Osteotomy*
Stress, Mechanical*
Tibia / physiology
Tibia / surgery*
Weight-Bearing