Elsevier

Journal of Biomechanics

Volume 49, Issue 16, 8 December 2016, Pages 4065-4072
Journal of Biomechanics

Acoustic emission in orthopaedics: A state of the art review

https://doi.org/10.1016/j.jbiomech.2016.10.038Get rights and content

Abstract

Acoustic emission (AE) is the phenomenon of sonic and ultrasonic wave generation by materials as they undergo deformation and fracture processes. AE monitoring is widely used throughout civil and mechanical engineering as a highly sensitive and non-destructive technique for structural health monitoring. Advances in computational power and digital data storage have generated much further interest in the possible applications of AE technology. Of particular interest has been its application within the field of Orthopaedic surgery.

This paper examines the current literature surrounding the use of AE technology within Orthopaedics and provides a comprehensive overview of its current applications within Orthopaedic surgery.

The use of AE technology in Orthopaedics is wide ranging and is discussed under the themes of: the study of the biomechanical properties of bone and fracture mechanics, research into failure mechanisms associated with cemented implants, prosthetic design, diagnostic value of AE and clinical application.

AE technology is of great benefit as an Orthopaedic research tool where AE counts can be used to provide a surrogate marker for damage accumulation and flaws can be monitored as they develop. More recently there has been increased interest in the possible clinical applications of AE technology and an appreciation of the potential benefits for the diagnosis and treatment of Orthopaedic pathology.

Despite the challenges involved when adopting AE techniques in vivo the potential of AE technology within Orthopaedics is significant. Already widely used in the research setting, clinical application has shown enormous potential and is a rapidly expanding area of contemporary research.

Aim

This analysis will review and summarise the current literature relating to the use of AE technology within Orthopaedic surgery

Introduction

The phenomenon of sonic and ultrasonic wave generation by materials undergoing deformation and fracture processes is termed Acoustic Emission (AE). AE results from the rapid release of energy during crack formation and propagation within a material and can be detected using specialist sensors. AE technology has been widely applied within civil and mechanical engineering to provide a highly sensitive and non-destructive method to monitor the health of structures. The technique enables both the detection and the location of structural flaws as they develop and, as such, the technology has proven invaluable in investigating the dynamic behaviour of materials (Ono, 2011).

A typical AE system consists of sensors, preamplifiers and a data acquisition system. AE sensors used in biomechanical engineering are typically piezoelectric, employing ceramic elements to generate electric signals in response to mechanical strain. Sensors are typically attached to the surface of the material under investigation using a thermo-plastic adhesive, with multiple sensors required to allow AE source triangulation. The analog signals detected by the sensors are amplified using preamplifiers and fed into a data acquisition system. The signals are converted into digital data, filtered and useful signals (“hits”) registered according to pre-defined parameters. The most common method for AE signal detection is based on threshold discrimination, where an amplitude threshold is defined and any signal exceeding this amplitude triggers a “hit” measurement (Muravin, 2009).

Fig. 1 demonstrates a typical AE signal triggering a “hit”. Annotations outline the standardised terms relating to the relevant parameters of AE signals and hits (MISTRAS, 1992).

Due to the large amounts of data generated through AE measurement research in this field has historically been limited and has principally centred on uses in engineering. Recent advances in computational power and digital data storage have, however, led to a marked expansion in AE research and to the development of increasingly widespread applications of the technology (Rashid and Pullin, 2014).

An area of recent particular interest is the application of AE technology to Orthopaedic surgery, where the non-destructive and highly sensitive nature of AE analysis make it ideally suited.

Section snippets

AE in Orthopaedics

Early applications of AE within Orthopaedics involved its use in vitro to characterise the structural and biomechanical properties of bone (Katz, 1979). It was established that the technique is particularly well suited to the dynamic analysis of bone deformation and fracture processes to which it was, and still is, frequently applied.

Subsequent work has seen AE technology applied within the field of arthroplasty research, with researchers taking advantage of its capability to monitor structural

Discussion

Acoustic Emission technology has been widely used in Orthopaedic research as a tool to assess micro-damage accumulation. More recently, however, there has been increased interest in the possible clinical application of the technology and an appreciation of the potential benefits of applying AE analysis during both the diagnosis and treatment of Orthopaedic pathology. This progression has led to an increased appreciation of, and interest in, the breadth of data available during AE monitoring.

Conclusion

Acoustic Emission technology has yet to find widespread clinical application within the field of Orthopaedic surgery. The technology has, however, been widely used in research where it has mostly been adopted as a research tool using AE signals as a surrogate marker for damage accumulation.

The technology has proven invaluable in the evaluation of the biomechanical properties of bone where it has been widely applied during bending and torsional testing (Aggelis et al., 2015) as well as

Perspectives - The future of AE in orthopaedics

Despite the promise shown in vitro, translation of AE techniques to in vivo applications faces many challenges. In addition to the complex structure of bone interfering with AE transmission, AE technology suitable for clinical application needs to be developed. When considering remote data collection, for example, AE sensors that are wireless and lightweight would be required. Identifying the relevant AE signals amongst extraneous noise is also a substantial challenge (Agcaoglu and Akkus, 2013).

Conflict of Interest

The author declares no conflict of interest associated with this article.

No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.

References (52)

  • L.K. Shark et al.

    Knee acoustic emission: a potential biomarker for quantitative assessment of joint ageing and degeneration

    Med. Eng. Phys.

    (2011)
  • C. Van Toen et al.

    Acoustic emission signals can discriminate between compressive bone fractures and tensile ligament injuries in the spine during dynamic loading

    J. Biomech.

    (2012)
  • Y. Watanabe et al.

    Prediction of mechanical properties of healing fractures using acoustic emission

    J. Orthop. Res.

    (2001)
  • J.G. Wells et al.

    Acoustic emission and mechanical properties of trabecular bone

    Biomaterials

    (1985)
  • T.M. Wright et al.

    Permanent deformation of compact bone monitored by acoustic emission

    J. Biomech.

    (1981)
  • S. Agcaoglu et al.

    Acoustic emission based monitoring of the microdamage evolution during fatigue of human cortical bone

    J Biomech. Eng.

    (2013)
  • D.G. Aggelis et al.

    Fracture of human femur tissue monitored by acoustic emission sensors

    Sensors

    (2015)
  • J. Brandt et al.

    Extended push-out test to characterize the failure of bone-implant interface

    Biomed. Tech. Biomed. Eng.

    (2005)
  • M. Browne et al.

    Passive monitoring of knee joint condition using acoustic emission

    Bone Jt. J.

    (2016)
  • M. Browne et al.

    Nondestructive evaluation of bone cement and bone cement/metal interface failure

    J. Biomed. Mater. Res.; Part B - Appl. Biomater.

    (2010)
  • M. Browne et al.

    The acoustic emission technique in orthopaedics-a review

    J. Strain Anal. Eng. Des.

    (2005)
  • R.A. Fischer et al.

    Analysis of the effect of using two different strain rates on the acoustic emission in bone

    J. Biomech.

    (1986)
  • X.-J. Gao et al.

    Evaluation of the fixation of artificial hip joint by acoustic emission

    Jpn. J. Appl. Phys.

    (1989)
  • Hanagud, S., Hannon, G.T. and Clinton, R., 1974. Acoustic emission and diagnosis of osteoporosis. In: IEEE, Ultrasonics...
  • K. Hasegawa et al.

    An experimental study on the interface strength between titanium mesh cage and vertebra in reference to vertebral bone mineral density

    Spine

    (2001)
  • Y. Hirasawa et al.

    Biomechanical monitoring of healing bone based on acoustic emission technology

    Clin. Orthop. Relat. Res.

    (2002)
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