Low intensity pulsed ultrasound enhances fracture healing in both ovariectomy-induced osteoporotic and age-matched normal bones

Authors

  • Wing-Hoi Cheung,

    Corresponding author
    1. Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
    • Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China. T: 852-2632-1559; F: 852-2632-4618.
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  • Wai-Ching Chin,

    1. Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
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  • Ling Qin,

    1. Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
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  • Kwok-Sui Leung

    1. Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
    2. Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, PR China
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  • Wai-Ching Chin contributed equally to this article.

Abstract

Low intensity pulsed ultrasound (LIPUS) was proven to enhance fracture healing effectively. Similar effect of LIPUS on accelerating the osteoporotic fracture healing was therefore hypothesized. The normal and osteoporotic fracture healings under this non-invasive biophysical intervention of LIPUS were compared and investigated. Closed femoral fracture procedures were performed on 120 Sprague–Dawley rats, in which 60 of them were ovariectomized (OVX). The rats were randomly assigned into four groups: sham OVX with treatment (Sham-T), sham OVX control (Sham-C), OVX with treatment (OVX-T) and OXV control (OVX-C). LIPUS treatment was 20 min a day, 5 days a week for durations of 2, 4, or 8 weeks. Results from weekly radiography, histomorphometry, micro-computed tomography and mechanical test showed both the treatment groups were with better healing responses than their control groups. Moreover, between the normal and the osteoporotic treatment groups, a significantly higher (p = 0.015) callus width (week 4), higher ratio of increment in bone volume to tissue volume ratio value (7.4% more), faster response of endochondral ossification and a higher stiffness measurement were observed in the osteoporotic treatment group. These comparable results on healing responses imply that LIPUS can be applied clinically to enhance both normal and osteoporotic fracture healing. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:129–136, 2012

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