Annals of Biomedical Engineering

, Volume 45, Issue 4, pp 1111–1121 | Cite as

Vibration Testing Procedures for Bone Stiffness Assessment in Fractures Treated with External Fixation

  • Lorenza MatteiEmail author
  • Antonia Longo
  • Francesca Di Puccio
  • Enrico Ciulli
  • Stefano Marchetti


A bone healing assessment is crucial for the successful treatment of fractures, particularly in terms of the timing of support devices. However, in clinical practice, this assessment is only made qualitatively through bone manipulation and X-rays, and hence cannot be repeated as often as might be required. The present study reconsiders the quantitative method of frequency response analysis for healing assessments, and specifically for fractures treated with an external fixator. The novelty consists in the fact that bone excitation and response are achieved through fixator pins, thus overcoming the problem of transmission through soft-tissues and their damping effect. The main objective was to develop and validate a test procedure in order to characterize the treated bone. More than 80 tests were performed on a tibia phantom alone, a phantom with pins, and a phantom with a complete fixator. Different excitation techniques and input–output combinations were compared. The results demonstrated the effectiveness of a procedure based on impact tests using a micro-hammer. Pins and fixator were demonstrated to influence the frequency response of the phantom by increasing the number of resonant frequencies. This procedure will be applied in future studies to monitor healing both in in vitro and in vivo conditions.


Fracture healing Bone stiffness Experimental modal analysis External fixator Mechanical vibrations 



The authors gratefully acknowledge Dr. Paolo Neri for providing the electromagnetic shaker, and Dr. Paolo Parchi for his suggestions regarding the focus of the research activity.


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Copyright information

© Biomedical Engineering Society 2016

Authors and Affiliations

  1. 1.Department of Civil and Industrial EngineeringUniversity of PisaPisaItaly
  2. 2.Department of Translational Research and of New Surgical and Medical TechnologiesUniversity of PisaPisaItaly

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