Applications of auxetic structures in orthopaedics: A scoping review

Background

Auxetic structures, meta-materials with a negative Poisson's ratio, exhibit unique mechanical behaviour, but there is currently limited use and understanding of how to leverage these structures in orthopaedics.

Objectives

This review aimed to systematically identify applications of auxetic structures within orthopaedics, particularly focusing on the rationale for using auxetic materials, the use of design for additive manufacturing to produce auxetic structures, and performance testing methods. Using a scoping review framework, trends and future directions in these areas were explored.

Methods

Following the Arksey and O'Malley guidelines and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses - Extension for Scoping Reviews checklist, a literature search was performed using Scopus, PubMed, Web of Science, ProQuest – Materials Science and Engineering databases, and Springer Link. Data was analyzed by content analysis.

Results

285 articles were identified, and 31 articles met the inclusion criteria. The areas of orthopaedic applications included structural implants (n = 18), tissue scaffolds (n = 10) and external bracing (n = 3).

Conclusions

The application of auxetic structures for orthopaedics is a growing field of interest and can potentially revolutionize the future of orthopaedic devices. However, further work investigating additional design for additive manufacturing techniques and performance testing methods is required to address the current limitations and advance the clinical translation of auxetic structures.