Mechanical and Clinical Evaluation of a Shape Memory Alloy and Conventional Struts in a Flexible Scoliotic Brace

Wing Yu Chan, Yiu Wan Yip, Kit Lun Yick, Sun Pui Ng, Lu Lu, Kenneth Man Chee Cheung, Kenny Yat Hong Kwan, Jason Pui Yin Cheung, Kelvin Wai Kwok Yeung, Chi Yung Tse

Research output: Journal article publicationJournal articleAcademic researchpeer-review

9 Citations (Scopus)

Abstract

Smart materials have attracted considerable attention in the medical field. In particular, shape memory alloys (SMAs) are most commonly utilized for their superelasticity (SE) in orthopaedic treatment. In this study, the resin struts of a flexible brace for adolescent idiopathic scoliosis (AIS) are replaced with different conventional materials and an SMA. The corrective mechanism mainly depends on the compressive force applied by the brace at the desired location. Therefore, the mechanical properties of the materials used and the interface pressure are both critical factors that influence the treatment effectiveness. The results indicate that titanium is the most rigid among the five types of materials, whereas the brace with SMA struts presents the best recovery properties and the most stable interface pressure. A radiographic examination of two patients with AIS is then conducted to validate the results, which shows that the SMA struts can provide better correction of thoracic curvature. These findings suggest that SMAs can be applied in orthoses because their SE allows for continuous and controllable corrective forces.

Original languageEnglish
Pages (from-to)1194-1205
Number of pages12
JournalAnnals of Biomedical Engineering
Volume46
Issue number8
DOIs
Publication statusPublished - 1 Aug 2018

Keywords

  • Bending stiffness
  • Flexible brace
  • Interface pressure
  • Material selection
  • Nitinol
  • Scoliosis

ASJC Scopus subject areas

  • Biomedical Engineering

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